Thoughts on methods of eliminating water changes ?

[Tristren]

Folks thinking about water changes need also to know that anyone who uses sodium bicarbonate/carbonate and calcium chloride for calcium and alkalinity is effectively doing water changes (especially in terms of export). This includes Glennf as well as folks using two part systems.

For example, in a tank requiring 2.2 dKH of alkalinity per day and the proportional amount of calcium will increase in salinity by about 64% over the course of a year. Since obviously folks maintain salinity, some water is removed.

That salinity reduction is equivalent, at least in terms of export, to about 8% changed monthly. It would also be equivalent to 8% changed monthly in terms of element import if the method used includes appropriate levels of all elements (as claimed by ESV/B-ionic and Balling methods).

Ok, I think I have been following up to this point. But in all of this (the water chemistry side of the hobby) I feel like I'm back in school at that point where I have read the theory and can maybe regurgitate it well enough so I think I get it, but haven't really internalized it so when I look ahead to some extrapolation in a future chapter I am lost.
So apologies for being the one to stop the class to ask for a refresher on something but can you explain:

"anyone who uses sodium bicarbonate/carbonate and calcium chloride for calcium and alkalinity is effectively doing water changes"

and then

"will increase in salinity by about 64% over the course of a year"

Thanks!
Tony

 

[Axelrodi202]

This thread has been a fascinating read. I come from the world of planted tanks, where more frequent water changes (weekly) are a widely accepted practice, but such systems are by necessity running with more nutrients.

Something I have yet to see discussed is hormones or other secretions by fish. In the freshwater world, it is well-established that certain fish, such as discus, excrete hormones while young that inhibit the growth of other fish. Hence discus grown in tanks where water is changed infrequently (even if it remains low in nutrients) will grow stunted, failing to reach proper length and shape, even if given ample space. Meanwhile discus grown in water changed very frequently (multiple times a day) will rapidly grow quite large, even in a small volume container.

Is this a topic discussed in the saltwater world? Do fish grown in systems with infrequent water changes grow more slowly and to a smaller size than those in systems with more water changes? I still do not have reef tanks (am very young and need to strike out on my own and accumulate the proper finances first), but when I do it would be for the purpose of having big fish (emperor angel, achilles tang), so this topic is of interest to me.

 

[Rick Krejci]

Great discussion! Through the years, I've had very stable (anemone/Soft) tanks that have gone 4-5 years without a water change just using Kalk in the ATO to keep calcium and Alk up. No sump, just had a HOB Deltec skimmer and no other filtration whatsoever. At the time not so much was known about the trace elements and I frankly didn't worry about it. Had a medium-low bioload and my numbers were always super stable with Nitrates always near 0. Water would yellow, so I would occasionally run a canister with Carbon for a day or so to clear it up. Never crashed, just had to tear it down to move.

I'm super interested in this discussion at this moment because I'm about to start a new tank (reefer 250) and am choosing an approach. I've always liked the natural approach, and am considering the Triton-ish approach with a great fuge light with Chaeto and a good skimmer. But am still pondering the matter.

I've also been considering a continuous water change approach, but my tank is in my living room so would be limited to the space under the sump. So 3 tanks, 1x ATO RO fresh water, 1x Empty tank for outgoing water and 1x Salt water for replacement. It would be nice to only have 2 tanks, an RO fresh and an empty for outgoing. Since I'm planning on a controller with salinity probe, I was wondering if it would be possible to dose the actual salt in granular form into a super high flow area based on salinity readings rather than pre-mixing the salt. This way, my RO fresh pump can act as both an ATO only, and when some water is removed from the tank, the ATO will replace its volume and the salinity would be adjusted if needed. This would also resolve the issue of the 2 part increasing the salinity as well as the Skimmer filling up decreasing the salinity. Not sure how I'd dispense the salt though...

Some obvious concerns...will the salt completely dissolve? Can one keep the salt in flowing form without caking. Or would it be possible to have the salt in "cake" form and just drop one at a time in? Not super comfortable with single point failure of salinity probe...maybe redundancy there?

May be an un-achievable idea, but it would really make the control system much simpler and make it more of a closed loop system from a salinity standpoint. Anyone tried this or considered it and found a fatal flaw?

 

[Ryanbrs]

I do not understand the whole discussion. At one hand – we have a lot of brands selling hobby grade tests – often based on colour depend optical determination by a human eye. Many of these tests claim that they can detect very low levels of the actual compound. There is test kits that claim very low levels of phosphorus – no one is talking about acid cleaning of vials in these case. Many people try to tweak their aquariums with methods that claim they could show reliable values around 10 ppb of phosphorus. This with instruments with a price below $100. We have tests that we tweak our levels of calcium, magnesium and alkalinity with. Tests that can be inaccurate after certain time after opening – but we are relying on them.

On the other hand we have tests that are a lot safer (but with limits also) that can be used as check points. But even here is necessary to use our own ability of perception in order to judge if the value is a “**** happens” value or a real. With these methods, as with hobby tests grade kits, it’s important to use them as a trend indicator and not relay on individually figures.

But I think it’s important to use the same vendor, the same test kits and so one. Is impossible to compare values between different vendors or test kits – they have all their own limits.

On example – I have done 4 test with Triton during this last year. According to calcium levels – they have shown levels around 500 ppm. My hobby grade kit has shown values around 400 – 430. The corals look good and they grow. I have try to maintain that level (400 – 420) with help of my hobby grade kit. Two weeks ago – my hobby grade test was empty and I got a refill of the same brand. Now it show around 470 – 480 ppm – closer to Triton. The plan now is to let it go down to levels (with my hobby grade kit) around 440 and in a month or two – send a new triton test.

I use the Triton test in order to see if there is some long term changes in my water. I have discover three trends that is steady – the potassium level is slowly going down (I do not use zeovit but a fast growing chaeto refugium) Now it’s time to put in some potassium and I´m able to calculate a daily dose in order to maintain a rather steady level. I have notice a slow increase of sulphur and high levels of silicates. The silicates – I probably know the source off – but the sulphur source is still unknown. I suspect the forming of hydrogen sulphide in my DSB and the following oxidation of this compound.

I´m using tap water – therefore I want to have an eye on the cupper levels in my aquarium.

As food I´m only using frozen food – no pellets, granulates or flakes.

The Triton test is for me a tool – like other tools in the hobby – but a tool that I do not want to be rid of because it works like a lever in order to get a better understanding and knowledge of my aquarium. But without the head beyond the keyboard – the results say nothing regardless of method.

Forum like R2R also helps in order to evaluate the figures and methods because we are a mix of people with different knowledges in different fields

And for the moment – I test with a very low rate of WC – I will evaluate what happens if you try to run the system as closed as possible including a high biodiversity. But WC will be a tool – if I need it

Sincerely Lasse

It is true that the reefing community has a fairly unrealistic expectation for accuracy with the hobby grade test kits we use. Regardless of what any of them claim they are really just designed to get you close and keep you there consistently which is adequate for almost all of our needs. Most of the good ones are consistent as long as the method is performed fairly similar each time but I would not call them accurate. We have struggled with this over the last year as we have looked for some of the more accurate solutions for reporting various parameters. We started by testing them against each other and they are all very different and worse yet each individual person performs and reads them differently. The obvious issue is, which kit or interpretation of the results is right? The answer, none. With most tests, you will never get a kit with tools, method, and instructions designed to be easy and affordable to produce lab quality results. You will also never get each person to perform and interpret the results the same.

For our own internal uses, it became obvious we need to create standards to test against so we moved on to freshly mixed artificial seawater spiked with Hach standards. After that, we also created standards using ACS sodium chloride for salinity and the related standard. All working with Hach for the best approach for each test, considering typical interferences. In the end, most of the $15-30 hobby grade test kits, related methods, and tools were accurate enough and most very consistent but a reading of 420 ppm calcium could easily be 390 as 450 and 8 DKH could be 7 or 9 depending on the kit, method and where your eyes determine the end point is. The color comparison kits are kind of all over the place because almost no one is reading the shades of green, pink or blue the same so it is hard to say. In the end I think you are best off not looking for the best or "most accurate" but the one which is easiest for you to personally perform and read consistently.

For calcium and alkalinity, I think we ended up determining the Hach kits were both the most accurate to the standards but also the easiest to consistently read the end points between multiple users. However, they are $260 and $290 each and I sincerely doubt that the average reefer is going to find a lot of value in this level of accuracy.

hhttps://www.hach.com/alkalinity-test-kit-model-al-dt/product?id=7640219547&callback=qs
https://www.hach.com/hardness-total-calcium-test-kit-model-hac-dt/product?id=7640219514

Point being, no matter what we are using to test I think we just need to have reasonable expectations for accuracy. The methods and procedures are really designed to provide cost effective "useable results" to get us fairly close to the goal. In the case of minor and trace elements, I think each individual needs to decide if they care at all. If they don't, all of them are a waste of time. If you are dosing trace element products, wanting some window into the results is certainly understandable and probably wise. From that point, it is just deciding the best of the available methods of doing so. I haven't used ICP tests long enough to comment on their value but I can say I never trusted many of the hobby grade trace element test kits out there and many either cost too much or take to long to perform to have value to me.

 

[Randy Holmes-Farley]

So apologies for being the one to stop the class to ask for a refresher on something but can you explain:

"anyone who uses sodium bicarbonate/carbonate and calcium chloride for calcium and alkalinity is effectively doing water changes"

and then

"will increase in salinity by about 64% over the course of a year"

Thanks!
Tony

Sure.

If you add sodium carbonate and calcium chloride, and let corals consume calcium carbonate for skeletons, you leave sodium and chloride in the water. That increases salinity over time.

In a perfect two part or balling, they add more things so that you leave more than just sodium and chloride. You leave everything that is in seawater.

So the net effect is no change in the composition of the water, but the salinity rises. That part is exactly like adding water during a water change.

When you adjust the salinity back to normal, that is exactly like removing water in a water change.

 

[Randy Holmes-Farley]

Had anyone else see this effect????

Many macroalgae do benefit from supplemental iron. Some can green up in a day or two of first dosing if they are depleted.

 

[Ryanbrs]

Great discussion! Through the years, I've had very stable (anemone/Soft) tanks that have gone 4-5 years without a water change just using Kalk in the ATO to keep calcium and Alk up. No sump, just had a HOB Deltec skimmer and no other filtration whatsoever. At the time not so much was known about the trace elements and I frankly didn't worry about it. Had a medium-low bioload and my numbers were always super stable with Nitrates always near 0. Water would yellow, so I would occasionally run a canister with Carbon for a day or so to clear it up. Never crashed, just had to tear it down to move.

I'm super interested in this discussion at this moment because I'm about to start a new tank (reefer 250) and am choosing an approach. I've always liked the natural approach, and am considering the Triton-ish approach with a great fuge light with Chaeto and a good skimmer. But am still pondering the matter.

I've also been considering a continuous water change approach, but my tank is in my living room so would be limited to the space under the sump. So 3 tanks, 1x ATO RO fresh water, 1x Empty tank for outgoing water and 1x Salt water for replacement. It would be nice to only have 2 tanks, an RO fresh and an empty for outgoing. Since I'm planning on a controller with salinity probe, I was wondering if it would be possible to dose the actual salt in granular form into a super high flow area based on salinity readings rather than pre-mixing the salt. This way, my RO fresh pump can act as both an ATO only, and when some water is removed from the tank, the ATO will replace its volume and the salinity would be adjusted if needed. This would also resolve the issue of the 2 part increasing the salinity as well as the Skimmer filling up decreasing the salinity. Not sure how I'd dispense the salt though...

Some obvious concerns...will the salt completely dissolve? Can one keep the salt in flowing form without caking. Or would it be possible to have the salt in "cake" form and just drop one at a time in? Not super comfortable with single point failure of salinity probe...maybe redundancy there?

May be an un-achievable idea, but it would really make the control system much simpler and make it more of a closed loop system from a salinity standpoint. Anyone tried this or considered it and found a fatal flaw?

I have not personally found salinity probes to be accurate or stable enough to automate any functions on the tank. I only use them for alarms and activating or deactivating non-critical equipment based on major deviations from the norm. Like closing a solenoid on the ATO line if the salinity has dropped substantially.

 

[jason2459]

They are highly susceptible to interference. I use my apex salinity probes for alerts and not to actually control anything. But normally I find them fairly accurate.

 

[Randy Holmes-Farley]

While I still don't believe that minor and trace elements are "required" for a successful reef tank, exploring potential benefits is a fun and interesting extension of the hobby. If a reefer is looking to explore the presumed benefits associated with maintaining them I have always operated under the principle that, for the same reason that water changes are not an effective solution for calcium and alkalinity in a medium to high demand tank they won't be for minor and trace elements as well. This presumes the important elements are depleted in a somewhat similar ratio has calcium and alkalinity. I don't know the accuracy of that statement. Thoughts ?

I agree that water changes may not adequately maintain trace elements (at least not all). I did 1% daily changes, but still dosed iron and silicate because they were rapidly depleted, and some other trace elements may have been depleted based on Triton testing (molybdenum, maybe others such as vanadium, but the Triton limits do not allow good quantitation at NSW levels for all of them). Dosing them is something I considered, but never carefully experimented with.

What I did do was add trace element cocktails several times over the years and never noticed anything notable to make it worth continuing.

 

[Randy Holmes-Farley]

They are highly susceptible to interference. I use my apex salinity probes for alerts and not to actually control anything. But normally I find them fairly accurate.

That may be because reefers do not use high quality enough conductivity probes. Te best probes use 4 electrodes

This is one of the first things I asked Trition USA when they told me the system was designed around a 2/4 part and limited to no maintenance water changes. Their answer was the system is designed to account for salinity and you can either skim wet to remove some salt water and combined with an ATO will appropriately dilute the tank over time. Alternatively, you can simply remove a small amount of water from time to time to supplement a dry skim. My follow up to that was "doesn't that process reduce all the other elements over time as well?" Thier response was that this is a well-understood process and the core 7 accounts for this effect. Hard to imagine that is done perfectly but it can certainly be significantly better than most. Like most of the claims manufacturers make, it is difficult to know how accurate they are in any other way than simply use the product and monitor the long term levels with the best of the available testing options we have.

Randy, do you have any thoughts on the possibility of such an approach and how close you could get? More or less an 8% monthly change through wet skimming combined with a 4 part designed to account for that dilution and keeps most of the elements in balance?

Both Tropic Marin (Balling) and ESV (B-ionic) claim to do this essentially perfectly. It should be no harder than making a salt mix match NSW, but there are costs associated with how "close" to exactly NSW you want to get for elements that are often present as impurities in other salt mix components at levels high enough to be important..

FWIW, I've never seen an analysis of either B-ionic or the Balling mixes to know how well they attain this goal.

 

[Ryanbrs]

I agree that water changes may not adequately maintain trace elements (at least not all). I did 1% daily changes, but still dosed iron and silicate because they were rapidly depleted, and some other trace elements may have been depleted based on Triton testing (molybdenum, maybe others such as vanadium, but the Triton limits do not allow good quantitation at NSW levels for all of them). Dosing them is something I considered, but never carefully experimented with.

What I did do was add trace element cocktails several times over the years and never noticed anything notable to make it worth continuing.

We often refer to them as magic elixirs at the shop but I like trace element cocktails better : )

 

[Randy Holmes-Farley]

This thread has been a fascinating read. I come from the world of planted tanks, where more frequent water changes (weekly) are a widely accepted practice, but such systems are by necessity running with more nutrients.

Something I have yet to see discussed is hormones or other secretions by fish. In the freshwater world, it is well-established that certain fish, such as discus, excrete hormones while young that inhibit the growth of other fish. Hence discus grown in tanks where water is changed infrequently (even if it remains low in nutrients) will grow stunted, failing to reach proper length and shape, even if given ample space. Meanwhile discus grown in water changed very frequently (multiple times a day) will rapidly grow quite large, even in a small volume container.

Is this a topic discussed in the saltwater world? Do fish grown in systems with infrequent water changes grow more slowly and to a smaller size than those in systems with more water changes? I still do not have reef tanks (am very young and need to strike out on my own and accumulate the proper finances first), but when I do it would be for the purpose of having big fish (emperor angel, achilles tang), so this topic is of interest to me.

We frequently discuss organic molecules and toxins that so many of the creatures we keep intentionally make to reduce predation and competition. But we have so many different organisms and analyzing organics is so difficult that there is very little specific information available.

We use a number of methods to export organics (GAC, skimmers, Purigen, other media), but the fact that some organics may accumulate and not be adequately exported by any of the means we use is one of the reasons I recommend water changes.

 

[Rick Krejci]

I have not personally found salinity probes to be accurate or stable enough to automate any functions on the tank. I only use them for alarms and activating or deactivating non-critical equipment based on major deviations from the norm. Like closing a solenoid on the ATO line if the salinity has dropped substantially.

Good feedback...I've been old school for so long, being a SW engineer, I'm looking forward to automating and monitoring. I just need to get to know the limitations before jumping to conclusions. Thanks!

 

[Randy Holmes-Farley]

Good feedback...I've been old school for so long, being a SW engineer, I'm looking forward to automating and monitoring. I just need to get to know the limitations before jumping to conclusions. Thanks!

Conductivity is, IMO, the best way to measure salinity (it is how chemical oceanographers do it) but the best instruments are not cheap (e.g., those using 4 electrodes, etc) and the probes should not be left in tank water 24/7 (IMO) because anything growing or getting stuck between the electrodes will alter the readings.

 

[Lasse]

I'm not laughing at you............you are focusing on the article...............I linked the article and told you to scan down and read table 7. It is a reference you asked for concerning trace element uptake by algae............the data in the table is relevant to the discussion in this thread.

For anyone interested I'd make note of the Zn and Mn levels.

algae trace metal uptake table by Big E 52, on Flickr

Another reference again in relation to the threads discussion and focus--


Gracilaria Parvispora dry weight analysis:

Nitrogen @ 2.50%
Phosphorous @ 0.082%
Potassium @ 13.54%
Calcium @ 0.555%
Magnesium @ 1.163
Sulfur @ 4.82
Zinc @ 139ppm
Iron @ 107ppm
Manganese @ 20ppm
Copper @ 7.0 ppm

A lot of people use macro algae for algae filters/refugiums. Chaeto and Gracilaria are popular choices. There is a ton of info on the web on algae uptake of trace elements and metals. If people want more info do some google searches as I've mentioned.

If you want to know what's in your algae from your scrubber take it to a lab and get a dry weight analysis.

Thanks a lot - this is important if you harvest a lot. I have notice a depletion of Potassium in my aquaria and I do not use zeolit - I suspected my macro for this and your reference give me right in that suspicion.

Sincerely Lasse

 

[Mark Gray]

https://www.bulkreefsupply.com/vide...v&utm_campaign=brstv&utm_content=brstv_080417

 

[Mark Gray]

Thanks a lot - this is important if you harvest a lot. I have notice a depletion of Potassium in my aquaria and I do not use zeolit - I suspected my macro for this and your reference give me right in that suspicion.

Sincerely Lasse

Thanks just starting to harvest now I went through your tank thread nice tank man

 

[Lasse]

Conductivity is, IMO, the best way to measure salinity (it is how chemical oceanographers do it) but the best instruments are not cheap (e.g., those using 4 electrodes, etc) and the probes should not be left in tank water 24/7 (IMO) because anything growing or getting stuck between the electrodes will alter the readings.

I use the probe of GHL and if you put it in an aera with strong current and are very carefully with temperatures during calibration - it works rathe good - give a stable level that change if you take out some saltwater and put in some freshwater. Mayby it not show the exact salinity but if I have 34.4 or 34.8 psu does not matter so much for me as long as I can use it as a relative tool

Sincerely Lasse

 

[Lasse]

This thread has been a fascinating read. I come from the world of planted tanks, where more frequent water changes (weekly) are a widely accepted practice, but such systems are by necessity running with more nutrients.

Something I have yet to see discussed is hormones or other secretions by fish. In the freshwater world, it is well-established that certain fish, such as discus, excrete hormones while young that inhibit the growth of other fish. Hence discus grown in tanks where water is changed infrequently (even if it remains low in nutrients) will grow stunted, failing to reach proper length and shape, even if given ample space. Meanwhile discus grown in water changed very frequently (multiple times a day) will rapidly grow quite large, even in a small volume container.

Is this a topic discussed in the saltwater world? Do fish grown in systems with infrequent water changes grow more slowly and to a smaller size than those in systems with more water changes? I still do not have reef tanks (am very young and need to strike out on my own and accumulate the proper finances first), but when I do it would be for the purpose of having big fish (emperor angel, achilles tang), so this topic is of interest to me.

It’s true that some fish (maybe most) can extract pheromones that make their fellows of the same species to grow much slower or to stop growing. But the examples I have seen (in practical fish farming) - it is specific pheromones for each species. I was growing Tanganyika ccichlids when I was young an we found out that if we had 200 of one species in a 250 l aquaria – we got stunted fish – but if we mix 4 species with 50 of each in the same aquaria – the stunting problem was much lesser.

In freshwater – it is also known that high levels of nitrate (NO3) inhibit growth for some species (> 200 – 300 ppm can affect the growth pattern for European eel as an example)

I do not think there is a “growth inhibition pheromone” problem in saltwater if you do not try to breed the same species in large number in the same tank. I think you can have a lot of fishes – of different species – in the same tank without problem



Sincerely Lasse

 

[Axelrodi202]

Thanks for the replies Randy and Lasse! As a freshwater hobbyist I am definitely jealous of all the organics export methods available to reefers, though as Randy mentions I am sure they do not remove 100%, especially over long periods. Very good point about species-specificity. Anecdotally it seems single discus do not experience the same stunting problems when raised with less water changes than would a group. Evolutionarily it makes sense that a fish's secreted growth-inhibiting hormones would only act on other individuals and not itself. So it seems this would not be an issue if say one were trying to raise an angelfish or tang to its full potential.