Equipment Review: Aquarium Engineering ACR (Automatic Calcium Reactor)

[svester]

Disclaimer: This thread is intended to be an objective review of the features, performance, vulnerabilities, and experience of owning an Automatic Calcium Reactor by Aquarium Engineering. It is not a thread about the company, the owner, war stories, or what have you. Please join the conversation if you have comments, questions, or interest, and lets discuss this piece of reefing gear!

Ok, lets get started!

Aquarium Engineering ACR - Review and Walkthrough
Model Reviewed: June 2020 Stacked 8" ACR

I bought the unit because I like "different" reef gear, solid engineering concepts, and I dislike how my pH probe was always wandering out of calibration and getting fouled in my old Calcium Reactor. This unit seemed worth the money, whereas I must say some of the other saturation reactors are just insanely priced.

Here are pictures of it disassembled and one of it running. As you can see, it is a saturation reactor, which means, it maintains a bubble of CO2 at the top of the reactor, and recirculates this through the volume of the reactor, maintaining a low pH in the water, dissolving the media until a state of saturation is reached upon which time the CO2 stops being absorbed by the water. The alkalinity, calcium, magnesium, and trace element rich water is then dosed into the aquarium by the controller. That same controller also feeds more CO2 into the unit when the float valve in the lid says the CO2 bubble has been depleted.

In this fashion, the reactor runs with no pH probe to wander out of calibration or foul. It pushes water up through the two chambers, and then recirculates it with a sicce pump.

The reactor must be fed with a pump, and ideally from an area devoid of microbubbles.

Here's a shot of the lid with the: Effluent out (left, clear), Purge line (middle, yellow), and CO2 recirc line (right, yellow). Also you can see the float switch cable (black).

Here is a pic of the regulator that comes with the unit, you can see that it is feeding the reactor at about 8 or 9psi.

Performance Review:

Construction is solid, parts are machined from PVC, the large tubes are clear PVC, and a lot of thought went into the design. Perhaps too much thought, because the units are constantly changing and being updated and improved.

The reactor is quiet during operation. In fact, the solenoids in the control module are the loudest part. Based on feedback in the facebook group, the control module is also the most failure prone portion in previous variants, though mine has been problem free.

Setup was straightforward using the instructions from AE, the unit does not come with instructions, or any assembly guidance at all, but the owner recently released a set of instructions online.

I am pleased to say that my unit was leak-free from the vendor, setup went exactly as planned, and it has been reliably churning out effluent for weeks now. Tomorrow when I get a chance I will test the reactor effluent alkalinity again, but it is very high as you would expect (30-40+dKh).

Media/Maintenance:

The suggested Magnesium media to go in the bottom chamber is remag (dolomite) and then reborn (coral skeletons) go in the top, larger, chamber. Although the new reborn (after the shutdown) is much smaller particles and seems more likely to clog and less prone to efficient water flow.

Basically, the unit then runs itself. Maintenance includes:

• Topping off media when it runs low
• Checking effluent potency from time to time to ensure proper operation
• Maybe changing effluent tubing in the control box? (unknown how long it lasts getting pinched)
• Recirculation and Feed Pump maintenance

The Control Module and valve module:

Effluent delivery is controlled by a super simple “time on, time off” control box. The top button is the “time on” that the solenoid will open for, then the bottom button is the “time off” that the solenoid will close the effluent line for. Want more alkalinity? Increase time on, or reduce time off. Want less? Reduce time on, or increase time off.

The CO2 bubble float switch is a simple conductivity switch, so your Apex could just as easily read it via a break-out box and control a Carbon Doser regulator to maintain the CO2 bubble in the unit, and the effluent could just as easily be metered with a Kamoer, Versa, or Masterflex peristaltic pump, but the stock system is working well so I have not had to enact “Plan B”.

Here is the inside of the valve module. On the left you can see the CO2 control portion, a check valve and a solenoid. Then on the right, the effluent control portion, a big old solenoid to pinch the effluent tube.

Final Thoughts:

So in summary, thus far, I'd give the unit an 8.5 out of 10. Only docking it 1 point for not coming with any instructions (people shouldn't have to join a facebook group to get instructions), and 0.5 point for the loud effluent control box. My unit is in a fishroom, and I can still hear the "CLUNK" of the solenoid opening and closing as it causes a water hammer. I may try a less forceful feed pump and see if that helps the situation (currently using a dedicated small magdrive). That being said, if the unit is in your living room, you may not love the bubble noises and solenoid noises. However, the unit is very solid construction, and other than the pinch-hose in the effluent control, I don't see many wear items if any, so I would expect the unit to last ages. AE uses high quality O-rings, excellent attention to detail of all machined parts, and everything fits together very well. When one buys a boutique piece of equipment, created by a largely one-man show, there are certain issues that are worth mentioning. For example if you have problems, shipping issues, need parts, etc, you need to find the owner, which can be easy or hard depending on the day, but I will say, based on the ownership experience thus far, I would buy this unit again.

Could you tell me or take a picture of you power supply. I know it 12v dc but need to order one and don’t want to get the wrong one

 

[Scubabum]

Could you tell me or take a picture of you power supply. I know it 12v dc but need to order one and don’t want to get the wrong one

Hey Svester. Reef Engineer no longer has this Calcium Reactor. I bought it along with his tank and gear. I follow this thread so happy to help with the picture of the Power Supply. Here you go:

 

[Dennis Cartier]

I have some controller developments to report. I have been running one of my v3 designs for awhile now and recently noticed that my auto purge function was not working satisfactorily. I found that the feed pump, or something inline with it, was slowing the flow of the feed water, so the fixed 1 minute purge cycle I was using was not allowing enough time to clear enough of the CO2 from the reactor. That got me to thinking about all the ways to feed the reactor.

At one point I considered using a peristaltic pump to feed the reactor, just like I am doing with the effluent. My concern about that idea back then was that I might accidentally generate too much pressure inside the reactor and pop a seam. After thinking about it today, I realized I am now using an IFM sensor that has 2 outputs, and I am only using 1 of the 2 to drive the Clippard valve. The other output was unused, so I could hook it to a relay and control a Masterlex peristaltic pump on the feed side.

So that is what I did. I used a 24v relay to interface into the Masterflex remote port. This allows the pressure inside the reactor to be used to control the operation of the feed pump. However, in my previous setup, the IFM is upstream of the CO2 check valve, so it would not actually be able to read the pressure that the pump could apply to the ACR. So I added a Plast-o-matic gauge guard and moved the IFM to downstream of the CO2 check valve.

I started my new controller design up and was not sure what to expect. I had visions of a popped ACR, lol. The first surprise was that the pressure reading on the IFM was super low and was not increasing. I had the IFM set to keep the Clippard open until 8 PSI, and then be disabled until the PSI dropped to 7.2 PSI. The gauge was barely able to reach 5.0 PSI and the Clippard was held open constantly. I started to wonder if the addition of the gauge guard had messed with the accuracy or sensitivity of the IFM. A quick test, pulling the IFM off and plugging it directly into the line coming for my regulator (set to 10 PSI), confirmed that it was reading accurately. On a hunch, I increased my regulator pressure to 12 PSI and the IFM on the ACR crept up to 6 PSI. Hmm, it seemed like the ACR was only able to get up to about half of the regulator pressure. So I increased my regulator pressure to 15 PSI, and the IFM went up to 8.0 PSI and disabled the Clippard. That seemed to do the trick.

Ok, so to control the feed pump, I have output 2 of the IFM set to stop the Masterflex when the pressure hits 7.2 PSI, and to restart the pump when the pressure hits 7.0 PSI. The idea is that when the water level in the ACR gets below the trigger point of the float switch, the feed pump will come on and re-pressurize the CO2 pocket, lifting the water level and keeping it very close to the trigger point of the float switch. As it turns out, that is exactly what it does. The Clippard opens much less frequently as compared to the previous version with the IFM upstream of the check valve. When it does open, it stays open for a few seconds instead of the tiny little burst it used previously. With the pump being used to limit the pressure on the downside, the PSI never falls below 7.0 PSI inside the ACR. Previously, the pressure would sometimes drop into the 5's or 4's when the water level was below the float valve. It was actually even worse because the pressure inside the ACR was probably about 50% of that based on the higher regulator pressures that I needed to use to get to 8.0 PSI (as measured on the wet side).

I have the feed Masterflex set to 20ml/min, which is about 4 times what the effluent pump is allowing out. The head and tubing I am using is good to 25 PSI of back pressure. So all good.

I am quite pleased with how my ACR is running with this new design. Hopefully my effluent strength does not change too much, but I am keeping an eye on my dKH levels just in case.

 

[Dennis Cartier]

After running the new configuration overnight, I can say that it is a huge improvement. Just like my DIY design ran better than the factory version, this is a step above that. Keeping the ACR as a sealed environment and directly controlling the internal pressure makes for a smooth running reactor.

However the pH of my external chamber has went lower than anytime in the past. It normally bottoms out at 6.12 the morning after a vent, and as of now, it is 6.09 and I suspect, still dropping. My alk has started to climb as a result. I will give it the rest of the day and adjust the duty cycle of the effluent pump lower if needed.

 

[Sisterlimonpot]

Long story short... you pressurized the reactor to allow more gas to stay suspended in water???

 

[Dennis Cartier]

Long story short... you pressurized the reactor to allow more gas to stay suspended in water???

Yes, but that was not my original intent. I kind of always assumed that my ACR was staying at saturation, but by keeping it under a constant, stable pressure, I have found that there was still room for improvement on the saturation front.

My original intent was to get a better handle on the cycling of the reactor and get things happening in an orderly deterministic way. Which this new setup does perfectly. A simple glance at the indicator LEDs on the IFM along with the pressure reading and I can tell what stage of a cycle the reactor is in now.

I am not sure if you are an ACR user or not, but they are saturation mode reactors like the Deltec and Dastaco. So keeping an excess buffer of CO2 available to super saturate newly added water is required.

 

[Sisterlimonpot]

Yes, but that was not my original intent. I kind of always assumed that my ACR was staying at saturation, but by keeping it under a constant, stable pressure, I have found that there was still room for improvement on the saturation front.

My original intent was to get a better handle on the cycling of the reactor and get things happening in an orderly deterministic way. Which this new setup does perfectly. A simple glance at the indicator LEDs on the IFM along with the pressure reading and I can tell what stage of a cycle the reactor is in now.

I am not sure if you are an ACR user or not, but they are saturation mode reactors like the Deltec and Dastaco. So keeping an excess buffer of CO2 available to super saturate newly added water is required.

I do not use a saturated CaRx like dastaco or acr, although I'm extremely familiar with the concept.

I think you're going to find out that pressurizing any CaRx will yield better results. Saturation (c02 absorption) under varying pressures will be different. The positive results you're seeing is due to pushing more gasses into suspension. If the acr was working as intended, just by increasing the reactor pressure, you'll be able to lengthen the interval between purge events because you're making better use of the co2 in the chamber. I think you will discover that [if] there is an underlying issue with the purge event, you fixed it by making the reactor more efficient.

I also think that if there is a carx out there inadvertently designed for positive pressure, the acr would rank high up there.

 

[Dennis Cartier]

I ran into a bit of a hiccup with the new controller methodology. The pH of my secondary chamber continues to drop, now at 6.04. What I did not expect is that the secondary, a Geo 618 without the CO2 feed, is getting quite fizzy with CO2 bubbles that are falling out of suspension at the lower pressure of the secondary chamber. I have inadvertently turned my secondary chamber into a CaRx.

So I guess I will lower the presets down to a lower PSI to prevent such an overabundance of CO2 getting passed along to the secondary. I will try a target of 4 to 5 PSI instead of the 7 to 8 PSI I am running now and see how that goes.

 

[Mark Gray]

I have some controller developments to report. I have been running one of my v3 designs for awhile now and recently noticed that my auto purge function was not working satisfactorily. I found that the feed pump, or something inline with it, was slowing the flow of the feed water, so the fixed 1 minute purge cycle I was using was not allowing enough time to clear enough of the CO2 from the reactor. That got me to thinking about all the ways to feed the reactor.

At one point I considered using a peristaltic pump to feed the reactor, just like I am doing with the effluent. My concern about that idea back then was that I might accidentally generate too much pressure inside the reactor and pop a seam. After thinking about it today, I realized I am now using an IFM sensor that has 2 outputs, and I am only using 1 of the 2 to drive the Clippard valve. The other output was unused, so I could hook it to a relay and control a Masterlex peristaltic pump on the feed side.

So that is what I did. I used a 24v relay to interface into the Masterflex remote port. This allows the pressure inside the reactor to be used to control the operation of the feed pump. However, in my previous setup, the IFM is upstream of the CO2 check valve, so it would not actually be able to read the pressure that the pump could apply to the ACR. So I added a Plast-o-matic gauge guard and moved the IFM to downstream of the CO2 check valve.

I started my new controller design up and was not sure what to expect. I had visions of a popped ACR, lol. The first surprise was that the pressure reading on the IFM was super low and was not increasing. I had the IFM set to keep the Clippard open until 8 PSI, and then be disabled until the PSI dropped to 7.2 PSI. The gauge was barely able to reach 5.0 PSI and the Clippard was held open constantly. I started to wonder if the addition of the gauge guard had messed with the accuracy or sensitivity of the IFM. A quick test, pulling the IFM off and plugging it directly into the line coming for my regulator (set to 10 PSI), confirmed that it was reading accurately. On a hunch, I increased my regulator pressure to 12 PSI and the IFM on the ACR crept up to 6 PSI. Hmm, it seemed like the ACR was only able to get up to about half of the regulator pressure. So I increased my regulator pressure to 15 PSI, and the IFM went up to 8.0 PSI and disabled the Clippard. That seemed to do the trick.

Ok, so to control the feed pump, I have output 2 of the IFM set to stop the Masterflex when the pressure hits 7.2 PSI, and to restart the pump when the pressure hits 7.0 PSI. The idea is that when the water level in the ACR gets below the trigger point of the float switch, the feed pump will come on and re-pressurize the CO2 pocket, lifting the water level and keeping it very close to the trigger point of the float switch. As it turns out, that is exactly what it does. The Clippard opens much less frequently as compared to the previous version with the IFM upstream of the check valve. When it does open, it stays open for a few seconds instead of the tiny little burst it used previously. With the pump being used to limit the pressure on the downside, the PSI never falls below 7.0 PSI inside the ACR. Previously, the pressure would sometimes drop into the 5's or 4's when the water level was below the float valve. It was actually even worse because the pressure inside the ACR was probably about 50% of that based on the higher regulator pressures that I needed to use to get to 8.0 PSI (as measured on the wet side).

I have the feed Masterflex set to 20ml/min, which is about 4 times what the effluent pump is allowing out. The head and tubing I am using is good to 25 PSI of back pressure. So all good.

I am quite pleased with how my ACR is running with this new design. Hopefully my effluent strength does not change too much, but I am keeping an eye on my dKH levels just in case.

Nice I don't have time to modify mine till after the first of the year, but I may come back and ask you a few questions

 

[Dennis Cartier]

ACR Controller v4

As some of you may know, Aquarium Engineering (AE) has ceased operations, so the ACR line of calcium reactors no longer has manufacturer support. With this in mind, I present the latest and (I think) the best version of a community sourced controller for operating the ACR line of calcium reactors.

This new version, although similar to the past v1, v2, and v3 versions of this project, operates in a completely different fashion. To see how it differs, we need to review how the factory controller works.

Factory Controller

The factory controller that came with the ACR’s (there are a number of different iterations of factory controllers) all operate similar to the following.

A pinch valve on the effluent line is triggered by a periodic timer where you can set the dwell and duty cycle. The feed from the tank is hooked to a manifold or dedicated pump that runs constantly. Each time the timer triggers the pinch valve, a stream of effluent is released back to the tank. You adjust the alkalinity level by varying the duty cycle and dwell time of the periodic timer to affect the amount of effluent returned by each cycle of the pinch valve.

A solenoid or in some cases, another pinch valve meters the CO2 addition. This is actuated by the float switch in the lid of the ACR. When the CO2 pocket in the top of the reactor shrinks, the float switch rises and actuates the CO2 addition. The volume of the CO2 pocket is supposed to (roughly) follow the level set by the float switch. The expectation is that as CO2 is dissolved into the water column of the reactor, the float switch rises and triggers the addition of fresh CO2. So the ACR operates based on the saturation level of CO2 within the water column.

In practice, a number of issues arise with the factory controller:

• Effluent can back flow into the tank should the feed pump ever stop. This leads to a possibly tank damaging alk spike (depending on flow rate)
• Too high of CO2 pressure can cause the water level to drop below the float valve and the CO2 pocket continues to expand until it reaches the circulation pump intake
• The pinch valves sometimes fail to close properly, dumping an unexpectedly large amount of effluent into the tank
• The factory controllers did not have adequate protection from water ingress, often allowing water to reach their CO2 components, causing corrosion, leeching and controller failure
• Hard to tune to get it running, and keep it running stable

The dependence on a pinch valve in the factory controller for effluent metering was to eliminate the need for a peristaltic pump to be used. In practice, the pinch valve caused too many issues to make it an acceptable substitution for the peristaltic pump.

The metering of the CO2 using a solenoid and float valve was more successful than the pinch valve on the effluent. However it suffers from only working correctly within non obvious limits. The regulator pressure being too high or the feed pump head pressure being too low, or too high can alter its performance and defeat the correct functioning of the reactor by allowing the CO2 pocket to ‘jump’ the float valve level and expand until it reaches the pump intake.

ACR Controller v1, v2, v3

The community developed controllers to replace the factory controller, replacing the effluent pinch valve with a peristaltic pump and using a much more durable and faster Clippard pneumatic valve to meter the CO2. In the v2 and v3 versions, a programmable pressure sensor was added to allow the pressures and timing of the Clippard valve to be adjusted. This helped to avoid the (obvious) corner cases that the factory controller exhibited, but overall, the v1, v2 and v3 controllers operated on the same principle as the factory controller. Only the cycling of the float valve was used to meter the CO2.

ACR Controller v4

For the 4th generation of the controller, a new method of operation has been incorporated. Instead of being driven solely by the float switch, the float switch now becomes just an input.

With the addition of the pressure sensor in the v2 and v3, we could now automate logic and processes based on the measured pressure. Unlike the previous versions, which only used the pressure sensor for the most basic things like displaying the real time pressure, limiting the maximum pressure, and tweaking the flow of CO2 through the Clippard valve.

In this latest version of the controller, the pressure sensor is now responsible for control of the reactor, not the float switch. The float switch is still required and used as a signal, but it is no longer solely responsible for control.

To accomplish this, we use a pressure sensor with 2 programmable outputs and featuring a finer resolution for the pressure presets. The first output (Output 1) controls the Clippard valve for CO2 addition, and the second output (Output 2) controls the feed pump for periodically adding feed water to the reactor.

We use a peristaltic pump for both the feed pump and effluent pump in this version. This allows the reactor to operate in a sealed fashion at a preset pressure. We are able to keep the internal pressure of the reactor within a 1.0 PSI pressure range of the reset, using the new methodology.

Settings for the pressure sensor for this example:

• Both outputs using hysteresis normally closed (hNC) setting
• Output 1 set point (sP1) set to 5.0 PSI
• Output 1 reset point (rP1) set to 4.2 PSI
• Output 2 set point (sP2) set to 4.4 PSI
• Output 2 reset point (rP2) set to 4.0 PSI

An example of a cycle using the new controller:

1. The pressure reads 4.6 PSI, both Output 1 and Output 2 are off.
2. The effluent pump is running, removing effluent and decreasing the water level within the reactor. As the water level decreases, the CO2 pocket expands and drops in pressure.
3. The pressure reading reaches 4.2 PSI, Output 1’s reset point, Output 1 is turned on and the Output 1 LED is lit. The Clippard valve is not energized at this point, as the float valve is (most likely) down and not floating.
4. The pressure reading reaches 4.0 PSI, Output 2’s reset point, Output 2 is turned on and the Output 2 LED is lit.
5. The feed pump starts pumping tank water into the reactor at a flow rate several times what the effluent pump is removing effluent at.
6. The pressure starts to rise inside the reactor as the excess feed water starts to raise the water level, compressing the CO2 pocket and increasing its pressure.
7. As the pressure reading rises, approaching Output 2’s reset point, the float valve will close when the water level rises enough for it to float.
8. The Clippard valve will be opened, driving the pressure higher and exceeding the set point of Output 2 (4.4 PSI). Output 2 is turned off.
9. The feed pump will be stopped as Output 2 has turned off.
10. The pressure will reach the set point of Output 1. This may take a couple of attempts as the newly added CO2 gets absorbed and the valve re-opens to add more until the preset (5.0 PSI) is reached.
11. Output 1 is turned off.
12. The pressure settles back to around 4.6 PSI as CO2 is dissolved. The cycle is now complete

Differences between the v4 controller and previous versions

The new version operates in a much smoother, deterministic way. At each step of a cycle, the specific equipment required for that stage of the cycle is enabled to move the cycle towards completion. This allows the controller to restart after venting and to recover from unusual startup conditions, and always move towards a stable cycle.

The CO2 valve is activated in a more sustained fashion compared to previous versions. Previously the Clippard would open for a fraction of a second to provide a small burst of CO2, and did this frequently.

The v2 and v3 versions had the pressure sensor installed after the Clippard valve, but before the CO2 check valve. This version has the pressure sensor installed on the wet side, after the CO2 check valve. This requires a membrane to be added to protect the sensor from water ingress and damage.

The previous versions would use much higher pressure presets. Because the pressure sensor is now reading the internal pressure of the reactor, a lower pressure preset is warranted. The back pressure on the CO2 check valve, reduced the internal pressure that was attained internally, so a reading of 8.0 PSI with the previous version was only reaching approximately 60% of the preset pressure (~5.0 PSI).

This version is highly tunable for different supplementation requirements by adjusting the pressure presets, in addition to the typical effluent flow adjustments.

Care in selecting the pressure presets is required, especially the set point of the output controlling CO2, as the internal pressure WILL be driven to that preset pressure. Selecting too high of a preset can damage the attached reactor. A limit of 5.0 PSI is suggested. Users with stacked reactors may need to use a lower preset to prevent leakage at the middle o-ring.

The new version can also support a manual and automatic venting cycle. The automatic vent, like previous versions, requires the addition of an additional relay, a timer and an electronic 3-way valve. For clarity, only the manual vent version is shown in the schematic.

New Hardware Requirements

The biggest change in the hardware is the need for a second peristaltic pump. The pump must be rated for continuous duty, have an adjustable flow rate, be able to auto start on power up, resume presets on power up and it is helpful if it can be remotely stopped and started. The pumps that tick all these boxes are the Masterflex pumps that are adjustable, and have a remote port for controlling the pump. The Kamoer FX-STP is also a good candidate. It can be toggled on and off easily as it uses a low voltage DC power supply.

The pressure sensor needs to support 2 outputs for this version, and the pressure range should be much lower to allow for a greater resolution of the presets. In the IFM product ranges, the PN7006, PN7007, PN7009, PN7206, PN7207 and PN7209 are all usable. They originate from Germany and are used often in the industrial and automation sectors. These are all discontinued parts, so they are only available from ebay and sell for a fraction of their original cost. Keeping an eye on listings, you can usually source one for < $50 and sometimes new in box listings come up for around the same price. For purchasing a new pressure sensor, Automation Direct offers the QPSL-AP-42 which supports 2 outputs and offers the needed resolution for presets. The Automation Direct parts originate in China. I no longer recommend the Automation Direct part as it appears it is not able to be used with liquids.

To protect the pressure sensor, a gauge guard that incorporates a membrane to keep the water from reaching the sensor is required. The Plast-o-matic GGMEB1-PP is suggested as it is the most affordable and provides good resistance to CO2. The (2) GGMEB1-PP guards that I tested had 100% failure rate. Both had the same deficiency, allowing pressure to leak across the membrane. I don't recommend these and instead suggest seaching Ebay for new in box (NIB) modesl of guards such as the GGMT1-PV. This is a discontinued part, so they cost about half of the GGME version but are tried and true. They were widely used in industry, so they regularly appear on Ebay.

To control the feed pump, a relay may be required. This would be driven by an output from the pressure sensor. For pumps that have a remote control port, like many of the Masterflex drives, or use a low voltage DC power supply, like the Kamoer, then a relay is the best choice. For toggling line voltage pumps (120V), an external power bar that has outlets that can be controlled directly from the pressure sensor output is a better choice. Something like the IoT Relay can be used to toggle a 120V outlet for the pump, on and off, directly from the pressure sensor.

The circuit diagram of the v4 controller is below.

ACR Controller v4 PDF

The v4 controller can be constructed using a project box to house the 24v power supply connection, the vent switch, the valve open LED and the feed pump relay (depending on feed pump type) , as well as making wiring connections. Both the pressure sensor and Clippard relay offer quality connection cables, so the pressure sensor and Clippard valve can be located remotely, near to the CO2/ACR components that they interface to, with their connection cables terminating inside the controller project box.

Selecting Pressure Presets

For correct operation of the controller, a few rules must be followed when selecting the pressure sensor presets. Below, we assume that Output 1 controls the CO2 and Output 2 controls the feed pump.

For discussion, the following labels apply:

• sP1 = Output 1 set point
• rP1 = Output 1 reset point
• sP2 = Output 2 set point
• rP2 = Output 2 reset point

The settings must adhere to the following:

sP1>sP2>rP1>rP2

Note:

1. The setting of sP1 will be the maximum pressure the reactor is exposed to. This setting must take into account the limits of the ACR to prevent damaging the reactor.
2. The setting of sP2 must be less than sP1 and greater than rP1.
3. The setting of rP1 must be less than sP2 and greater than rP2.
4. The setting of rP2 must be less than the setting of rP1. This will be the lowest pressure the reactor operates at, during normal operation.

This post will be updated with further info/build details as they become available.

 

[Sisterlimonpot]

Seems well thought out. The availability of the pressure sensors seems a concern. Do you think there can be a suitable substitute to a sensor that is more readily available?

 

[Dennis Cartier]

Seems well thought out. The availability of the pressure sensors seems a concern. Do you think there can be a suitable substitute to a sensor that is more readily available?

Update: The QPSL-AP-42 is not rated for use with liquids, so it can't be used in a v4 controller. Only the IFM parts are known to be compatible.

The QPSL-AP-42 from Automation Direct is readily available off the shelf and is affordable ($84.00). They also offer an IFM clone, sourced from China, that is a more expensive ($272.00). I would rather purchase a used IFM though than pay that much for a clone.

I use the IFM products as I found them first, so I purchased quite a few off ebay before I found the Automation Direct parts. I have (6) PN7007 parts arriving next week in fact, that I snapped up for $50 each, unused, brand new in their original boxes.

Because the IFM sensors are so widely used in industry, as retired equipment is being broken down, there is a steady supply of equipment pulls that appear on ebay. In my experience keeping an eye on listings and waiting for a unit that is in good shape, is the right model and is available at a decent price is pretty easy. Just don't be too quick to jump on the first listing you see as better/cheaper ones are usually on the way. I consider $30 a good price for a used one in good shape.

Automation Direct is a good source for the connection cables that the IFM sensors (and the Chinese clones) use. The QPSL-AP-42 model includes it's own cable. So you save a bit, by not having to purchase one, like you do for an IFM.

 

[panic]

I just found my controller full of water. It's toast, so I will be making a shopping list to build your controller Dennis, thank you!

-edit, I think building this might be way out of my league

I also bought the new version of his controller with the built-in peristaltic pump. Does anyone have the apex program to get this going?

 

[Dennis Cartier]

I just found my controller full of water. It's toast, so I will be making a shopping list to build your controller Dennis, thank you!

-edit, I think building this might be way out of my league

I also bought the new version of his controller with the built-in peristaltic pump. Does anyone have the apex program to get this going?

Building it is not that hard actually. I can also lend a hand if need be.

Can you post a picture of the updated controller with the peristaltic pump as I have never seen that version?

 

[Dennis Cartier]

Update: The QPSL-AP-42 appears to not support the use of liquids, so use in a v4 controller is
not possible.

Anyone who is thinking of building a v4 controller, please hold off on buying the QPSL-AP-42. I am waiting for a response from Automation Direct concerning it's ability to be used with a gauge guard. The reason is that you have to fill the sensor side of the guard with liquid, normally oil or water, and the AD part only lists gases as a medium. So I want to confirm that it can be liquid filled. Otherwise it will only work on the dry side (before check valve) and can't be used in a v4.

I am in the process of building a v4 controller for a forum member, and @panic 's recent factory controller failure got me to thinking that it would be helpful if I had a couple of pre-built v4 controllers on the shelf for exactly these sorts of events. Then when a factory controller expires, I can simply overnight it to the affected tank owner to minimize the impact of the failure on the tank. I have started collecting up parts to build 2 controllers.

Everything will be at cost, plus the shipping. There will be no charge for assembling it, because that would make it in to a job, and being retired, I only want a hobby, not a job.

 

[panic]

I’d love to get one of those Dennis! I have all the pieces for the v1 coming Tuesday. Dosing and frequent water changes is keeping my alk up while I lack the calcium reactor and I’m seeing burned tips on a few acros and the euphelia are shrunk up a little. All is OK in the reef for now.

Here is the “new” controller I barely received from AE before he went completely silent:

Here’s my old controller when I opened it up:

 

[Dennis Cartier]

I’d love to get one of those Dennis! I have all the pieces for the v1 coming Tuesday. Dosing and frequent water changes is keeping my alk up while I lack the calcium reactor and I’m seeing burned tips on a few acros and the euphelia are shrunk up a little. All is OK in the reef for now.

Here is the “new” controller I barely received from AE before he went completely silent:

Here’s my old controller when I opened it up:

I thought you might! I am glad to hear that you have your tank stabilized. I plan to post a thread in the DIY section to help others see a v4 being built step by step, so you will get to see your controller being built.

Ok, I have never seen that controller before, but I can make some educated guesses on how it works. There will be a stepper driver inside along with Bill's typical CO2 hardware (check valve, solenoid|pinch valve). The interface on the front is a PWM speed controller. Using it you can adjust a square wave that will be advancing the stepper motor by way of the stepper driver. Each transition of the square wave will advance the stepper 1 step. So you essentially set the speed of the stepper and control the flow through the ACR by adjusting the speed of the pulses. The Apex cable is either as a signal to an Apex, or possibly as an alternate source of pulses to the stepper driver to allow the speed to be varied by the Apex. It could be either.

Wow, that factory controller is full! The check valve that you can see if the photo is from the RODI industry and is not intended for CO2. I recently had the Murlok version of that valve fail on me and had an air pump fill with water, so I no longer recommend them in any capacity for tanks and would never have thought their use with CO2 was a good idea.

 

[second_decimal]

I built the v3 controller (with help from Dennis) and it works great. One challenge I ran into was the noise from the recirculating pump. My tank is pretty much silent so little noises become glaring jackhammers. The suction intake from the recirculating pump kept sucking in Co2 bubbles rising to the top of the reactor causing the pump to cavitate and creating all sorts of undesirable noises. I was able to address this with a simple 2 liter plastic bottle and creating an angled shield to divert the bubbles to the opposite side of the reactor where they are too far away from the intake to get sucked in. This was very simple with just some scissors and now it is silent. Sorry I didn’t take any pictures but it really is not complicated. Other than that, the controller is solid, silent and works great. I will be upgrading to v4 though since it seems to capture more of the technological capabilities of the IFM.

Thank you Dennis!!

 

[panic]

I built the v1 with help from Dennis, thank you again Sir. My Alk has been just as stable as it was with the ACR. I have the purge set as I did before to expel room air introduced to the reactor from normal use as I had before using the Apex (once a day for 90 seconds, I think). This was a simple fix as far as building it. I highly recommend at least having these parts on the ready for anyone with the ACR for WHEN it fails.

 

[Dennis Cartier]

I built the v1 with help from Dennis, thank you again Sir. My Alk has been just as stable as it was with the ACR. I have the purge set as I did before to expel room air introduced to the reactor from normal use as I had before using the Apex (once a day for 90 seconds, I think). This was a simple fix as far as building it. I highly recommend at least having these parts on the ready for anyone with the ACR for WHEN it fails.

Your welcome @panic . I agree, having either a ready to go v1 or the parts to build one on hand is a very good idea for anyone running a factory controller on an ACR still.

Can you share the details on how you are purging with the Apex on your ACR? I don't use Apex, so I had not really considered that users may want to leverage their Apex for implementing the venting and purging of the ACR. Offering Apex users the ability to integrate would probably remove the need for a standalone timer and possibly the DIN relay that the venting requires.

The v4 controller design is progressing nicely. I have built one so far for a forum member and it allowed me to fine tune the process. However I got an unexpected result when I upgraded my own controller to using the budget friendly gauge guard and I am doing some testing to see if the differences in the guard are the source of the issue, or if it is just a defective guard.

Here is an example of what a v4 unit build will look like.

I built a jig to assist with the placement and drilling of the holes, but sadly my drill press is too limited in vertical height to accommodate it. So I had to drill the holes in the jig, and box, by hand and managed to mess the spacing up. Doh.