Tested pH with lab pH meter and it's 7.5!

[arking_mark]

I will bring to my lfs a sample of water for doublecheking the kh, since I am 100 % sure about pH. And yes, obviously aeration test was performed outside

Then your pH meter is off or something else is going on.

 

[KonradTO]

Then your pH meter is off or something else is going on.

PH meter cannot be off because I tested with 2 different meters and they were differing only by 0.1

 

[arking_mark]

PH meter cannot be off because I tested with 2 different meters and they were differing only by 0.1

So there is a mathematical model for pH, dKH, and CO2. Given any two of these #s, you can calculate the 3rd. Clearly your #s don't add up.

To simply figuring out what's wrong, instead of using tank water, use a batch of freshly mixed artificial salt water. Aerate it outside for an hour and then measure the pH. If you are getting a pH number below 8.2 NBS your meter(s) or measurement techniques are off.

Two pH meters matching could just mean they were both calibrated wrong. This could happen if the calibration fluids used are off.

 

[Randy Holmes-Farley]

PH meter cannot be off because I tested with 2 different meters and they were differing only by 0.1

Maybe they were both calibrated with the same wrong buffer, or not calibrated.

I suppose its possible the aeration needs to go longer, or didn't use normal CO2 air, but there's no uncertainty what pH should be if the alk is at least 6 dKH.

 

[Reef.]

PH meter cannot be off because I tested with 2 different meters and they were differing only by 0.1

Were both the indoor and outside tests carried out at around the same temps?
Not sure if this would account for your results but would have an affect on your results if the temps were vastly different.

 

[KonradTO]

Yeah something is not working either my kh test or there could be some problem with the calibration buffer in the lab. I will check freshly mixed water and see what I get. Also my "guy" at the lfs told me that he will bring his personal test kit (salifert) to check what's going on (they use jbl which apparently doesnt work well with saltwater)

 

[ReefGeezer]

A good investment is a Milwaukee or PinPoint pH meter. They aren't expensive, are accurate enough, and can be bought used. Be advised when buying used, you might have to buy a new probe. They are often "dried out" and inoperative. Two-point calibration using standards below/above the expected range is still the all important factor when trying to get accurate readings.

 

[KonradTO]

Ok I just came back from the lfs. His measurement of kH were different from what I get with my test:
With salifert Kh measured 7.8 dkh
For pH he was going to use a normal jbl test and told me to come back tomorrow when he will bring his ph probe. Also salinity is a bit low (33ppm) which might be one of the reasons why kH is so low. I use red sea coral pro salts which should give a kH of 11.5 at 35 ppm.

 

[KonradTO]

Will sodium carbonate increase my pH a bit if I raise my kh from 7.8 to 11-12 dkh?

 

[Randy Holmes-Farley]

Will sodium carbonate increase my pH a bit if I raise my kh from 7.8 to 11-12 dkh?

There are two effects.

Regardless of how you raise the alkalinity, the pH will rises because higher alk at the same CO2 levels will result in higher pH. That is a "permanent" sort of effect.

What you use to raise the alkalinity ranges from things with a small pH lowering effect when first added (sodium bicarbonate) to things that raise pH a fair amount when first added (sodium carbonate) to things that raise pH a lot when first added (sodium hydroxide). This effect only lasts until the tank comes back into equilibrium with teh CO2 level. Of course, if you end up adding some every day, you get a "temporary" pH boost every day.

The temporary effects are about as shown there for a 1.4 dKH instantaneous alk boost:

bicarbonate; -0.06 pH units
carbonate: ~0.35 pH units
Hydroxide: ~ 0.7 pH units

The exact rise (or fall) will depend on the absolute alk you are starting from (higher alk gives a smaller rise or fall due to more buffering).

 

[KonradTO]

There are two effects.

Regardless of how you raise the alkalinity, the pH will rises because higher alk at the same CO2 levels will result in higher pH. That is a "permanent" sort of effect.

What you use to raise the alkalinity ranges from things with a small pH lowering effect when first added (sodium bicarbonate) to things that raise pH a fair amount when first added (sodium carbonate) to things that raise pH a lot when first added (sodium hydroxide). This effect only lasts until the tank comes back into equilibrium with teh CO2 level. Of course, if you end up adding some every day, you get a "temporary" pH boost every day.

The temporary effects are about as shown there for a 1.4 dKH instantaneous alk boost:

bicarbonate; -0.06 pH units
carbonate: ~0.35 pH units
Hydroxide: ~ 0.7 pH units

The exact rise (or fall) will depend on the absolute alk you are starting from (higher alk gives a smaller rise or fall due to more buffering).

Wow thanks! So basically it's better to raise kh slowly and spread each day the sodium carbonate dose, since I can benefit also of a slight pH boost every time I dose it. I am gonna raise kh from 7.8 to 11 so I should expect an increase of 0.7 ph each day right? Or the 0.7 increase gets shared between each day I divide the solution for?

 

[Randy Holmes-Farley]

Wow thanks! So basically it's better to raise kh slowly and spread each day the sodium carbonate dose, since I can benefit also of a slight pH boost every time I dose it. I am gonna raise kh from 7.8 to 11 so I should expect an increase of 0.7 ph each day right? Or the 0.7 increase gets shared between each day I divide the solution for?

How much alk you add each day depends on the consumption in the tank, but usually is more like 0.5 to 2 dKH per day.

The effect of an addition can drop back in a few hours, and spreading out the addition makes the overall rise smaller, but may make the average pH a bit higher than all at once dosing.

 

[alberttjohn8]

I just came back from the lfs. His measurement of kH were different from what I get with my test:
With salifert Kh measured 7.8 dkh
hello dear
Teatv

 

[KonradTO]

How much alk you add each day depends on the consumption in the tank, but usually is more like 0.5 to 2 dKH per day.

The effect of an addition can drop back in a few hours, and spreading out the addition makes the overall rise smaller, but may make the average pH a bit higher than all at once dosing.

I don't have corals so apparently it's mostly due to macros consumption. Still as far as I understood from previous replies even a kh of 7.8 should prevent my pH to drop so low right?

 

[KonradTO]

Ok not much I can do right now other than:
Test from a 3rd source my pH (lfs)
I will bring kH to 10-11 with sodium carbonate within 3-4 days (is it slow enough?) and test pH daily
leave my tank open for this time. I do not have an ato as with the lid I get no evaporation at all, but I will top off manually.

I also have an ongoing ostreopsis outbreak so I am doing some more stuff on that regard in the meanwhile. Hopefully raising kH and pH will help that as well

 

[Adam1985]

Ok not much I can do right now other than:
Test from a 3rd source my pH (lfs)
I will bring kH to 10-11 with sodium carbonate within 3-4 days (is it slow enough?) and test pH daily
leave my tank open for this time. I do not have an ato as with the lid I get no evaporation at all, but I will top off manually.

I also have an ongoing ostreopsis outbreak so I am doing some more stuff on that regard in the meanwhile. Hopefully raising kH and pH will help that as well

Personally I’d first try to relax as if you’re anything like me, this situation is driving you crazy. It might seem like everything is going wrong at the same time.

Issue is if you try to fix the problems all at the same time, it’s hard to know what worked and didn’t.

If it were me, I’d start by establishing a simple test routine with reliable kits/equipment. For example, I test pH, T, sal, KH, NO3, and PO4 almost daily. I think we could help you on the testing topic separately, as good data is very important. I realize you’re already working on this part as well.

After establishing the routine, I’d then start documenting the baseline numbers and write in a notebook or app your test results and what you do with your tank from here out. Date and time of each entry; try not to miss entries if you test or take actions with your tank. But this isn’t to chase numbers, it’s to build a database so we can understand cause and effect in your particular system.

If it were me based on what you describe, for actions on the tank, I’d start with a series of WC’s, frequent but smallish ones, made with clean RODI and your desired salt to get the parameters you want. Perhaps 10% every other day for two weeks or until things get back on track. Keep temp and salinity of the fresh saltwater similar to the tank as usual.

I’d consider if a rip clean might help, it’s something to think about. You can search it on here. But in any case even if not doing a rip clean, I’d make sure to remove any dead/dying macros or any detritus you can reach without breaking the tank down. Turkey baste your rocks.

For pH, while you don’t have a sump, if you could swing a good quality HOB skimmer with a CO2 scrubber on the air intake, you’ll see a step change pH improvement. Later you could consider full or partial recirculation. If you can’t do a skimmer or prefer not to, perhaps you could somehow scrub the air feeding your airstone (I’m thinking air pump -> hose -> scrubber -> hose -> check valve ->hose -> airstone). Placing the air pump outside might also be a helpful action if inside air CO2 levels are driving your pH down.

Regardless of the skimmer/scrubber topic, if you want higher alkalinity I’d suggest you start using a good and complete two part. I personally use Randy’s high pH recipe with strontium added. If you’d truly rather avoid NaOH, you could use Na2CO3. But NaOH will give the biggest pH boost as Randy mentioned.

Then put the two part on a dosing pump and divide into as many small doses as you can, into a high flow area for quick dilution, avoiding direct contact with tank inhabitants, and not forgetting to offset the part 1 and 2 dosing times to avoid precipitation. For total starting dose, you could use the BRS 2 part calculator as the strengths of both recipes are the same.

I’d then continue the routine and test daily around the same time for at least 1-2 weeks before making further changes, except for slight tweaking up or down on the two part dosing. For raising your alkalinity from 7.8 dKH to 10 dKH, maybe doing that over a couple of weeks would be better than a couple of days. Skipping a test here and there is fine; judge your progress by how your tank looks. Photos can be helpful to evaluate changes over time which are hard to notice as we look at our tanks so often.

If it were me, I’d start with the water changes and high pH two part while planning out what to do/not do with the scrubber/skimmer topic. I’d check ammonia and make sure you don’t have any significant amount before increasing the pH.

At the two week mark, and with two weeks of data, I think we could then evaluate the situation and plan next steps.

I hope this helps, I’ve been in the same boat and it isn’t fun. But we’re all here to help you get through it.

Adam

 

[Reef.]

I just came back from the lfs. His measurement of kH were different from what I get with my test:
With salifert Kh measured 7.8 dkh
hello dear
Teatv

With salifert if you stop as soon as you see a lavender colour the kh will be accurate, salifert is very good for kh but the instructions are misleading, if you try and match the colour they show in the instructions the result will be wrong.

 

[KonradTO]

Wow thanks for the detailed answer!

Issue is if you try to fix the problems all at the same time, it’s hard to know what worked and didn’t.

True. I unfortunately had too much of dinos at the moment (they started growing on my porcelain crab too !!). I must say that after yesterday I installed the UV light and cut all the macros overgrown with dinos, the situation now looks much better. I covered the tank with towels and turned off all my lights. For now it seems clean but I know its too early to decide if it worked.

If it were me, I’d start by establishing a simple test routine with reliable kits/equipment. For example, I test pH, T, sal, KH, NO3, and PO4 almost daily. I think we could help you on the testing topic separately, as good data is very important. I realize you’re already working on this part as well.

Yes I usually do this weekly. My problem was that with my test kit for pH, for example, I was sure I had ph 8, but apparently the test was not that accurate. I also found out that if I use my pipette for measuring the water for the test it differs from the vials provided by the test brand (sera). Basically they say "fill until 5ml mark" but its not really 5ml. This had me testing for weeks in the wrong way probably.
I tested today pH at my lfs but I think that- their pH probe is not working well. Was giving pH 7.1 and all the other probes in the lab are on 7.6-7.7 range. I get basically 3 different measures from 3 different probes.

If it were me based on what you describe, for actions on the tank, I’d start with a series of WC’s, frequent but smallish ones, made with clean RODI and your desired salt to get the parameters you want. Perhaps 10% every other day for two weeks or until things get back on track. Keep temp and salinity of the fresh saltwater similar to the tank as usual.

Yes this sounds like a good idea. I actually was reducing WC to increase my N and P, but since I can dose now I could try with this.

I’d consider if a rip clean might help, it’s something to think about. You can search it on here. But in any case even if not doing a rip clean, I’d make sure to remove any dead/dying macros or any detritus you can reach without breaking the tank down. Turkey baste your rocks.

I would rather avoid rip clean since I don't have another tank where to relocate temporarily my stuff. Also fish and inverts look healthy, better not to play with fire.

For pH, while you don’t have a sump, if you could swing a good quality HOB skimmer with a CO2 scrubber on the air intake, you’ll see a step change pH improvement. Later you could consider full or partial recirculation. If you can’t do a skimmer or prefer not to, perhaps you could somehow scrub the air feeding your airstone (I’m thinking air pump -> hose -> scrubber -> hose -> check valve ->hose -> airstone). Placing the air pump outside might also be a helpful action if inside air CO2 levels are driving your pH down.

Yes this is also what the guy at my LFS told me. I am just a bit ticked because everything comes with big costs with this hobby and if I can manage to solve the problem without buying a lot of unnecessary items I would rather try that way. Many people told me that skimmer is not necessary since I have so many macros, but I did not consider the problem with pH. My plan now would be to raise kH to the upper limit (11-12 dkH) and see how it goes with pH. If stays stable around 8 despite CO2 higher than usual I would be happy. If it does not work I am going to either install a sump or get a hob skimmer and co2 scrubber.

Regardless of the skimmer/scrubber topic, if you want higher alkalinity I’d suggest you start using a good and complete two part. I personally use Randy’s high pH recipe with strontium added. If you’d truly rather avoid NaOH, you could use Na2CO3. But NaOH will give the biggest pH boost as Randy mentioned.

What's the difference with Na3CO3 only? I tested Ca and Mg and they are in the right range, giving that I have no corals yet. Maybe coralline could be using those in the long term.. I can see it growing quite fast on the back of the tank.

I’d then continue the routine and test daily around the same time for at least 1-2 weeks before making further changes, except for slight tweaking up or down on the two part dosing. For raising your alkalinity from 7.8 dKH to 10 dKH, maybe doing that over a couple of weeks would be better than a couple of days. Skipping a test here and there is fine; judge your progress by how your tank looks. Photos can be helpful to evaluate changes over time which are hard to notice as we look at our tanks so often.

Yes good point. I have no dosing pumps yet (I actually don't even have a decent led for corals yet), but I can just manually dose every morning and evening dividing the solution 14 times.

I hope this helps, I’ve been in the same boat and it isn’t fun. But we’re all here to help you get through it.

Adam

Thanks so much for the advice. I am not too much concerned until my livestock is healthy and eating, but until I solve this ph and dino problems I don't want to add corals. Which is annoying but, well, better to wait than to waste money and corals.

 

[KonradTO]

With salifert if you stop as soon as you see a lavender colour the kh will be accurate, salifert is very good for kh but the instructions are misleading, if you try and match the colour they show in the instructions the result will be wrong.

yes the guy from the LFS did the whole process in front of me. Colour started to shift around 7.5 dkH and was as the test instructions at 7.8. SO let's say I am below 8. Which is weird because I use coral pro salts from red sea, which should have 12 dkH. My plants and coraline are depleting it faster than I tought. I was reading somewhere that if you don't have corals 10% WC should be sufficient for elements depletion but my macros do not agree XD

 

[Reef.]

Check your salinity, something is not right, most likely a testing error or salinity is off, but your salinity would have to be crazy low to be 4 dkh off.

I think the evaporation will be less than you think, my tank is 14g with a mesh lid, maybe 500ml evaporation a day. Boiling the kettle or taking a bath/shower would put much more moisture into the room than a small tank.