pH question you may not have encountered

[John J in Pickens]

I am about to fire up my BioCube 16 tank this weekend or next. I have two Ocellaris Clowns (tank raised for the past 7 years) that I intend to transfer to the bioCube. For the past 7 years, they have lived in a 10-gallon tank that has a trickle filter built in, along with a couple of small Hermit Crabs. Granted, I have not done water changes near as often in this tank as I should have (usually like one gallon per month), but the Clowns have done fine, eat like pigs, and are about 3 inches long.

I decided this morning to test the water in the 10-gallon tank using my new API Saltwater Master Test kit. As I figured, the Ammonia level and Nitrite levels were zero. The Nitrate level was high, 160 ppm. I had a feeling the pH would probably be low, and it was, only 7.4 ppm. I'm concerned as to what to do to get the Clowns used to a higher pH.

I don't know at this point if a water change is what I should do or not. The clowns have been living in this low-pH level tank for years, and by all accounts seem fine. I know that when I put in the water for the BioCube, the pH level should be acceptable (I am buying seawater from my LFS). Should I do some kind of slow drip acclimation to adjust the pH on the clowns from 7.4 to the pH of the seawater I am buying for my BioCube? I haven't asked the folks at the LFS what the pH level is of the seawater they sell, but I am fairly sure it is acceptable. If I went this route, how long should I take doing a drip acclimation to bring the pH up for the clowns before putting them in the BioCube? I have also seen a product called Proper pH 8.2 Powder. Has anyone used it? Would this be a good way to raise the pH in the 10-gallon tank to get the clowns used to a higher pH?

I can promise you that I certainly will not allow the pH (and nitrate) levels to get out of line with the BioCube once it is up and running. I am grateful for any assistance that is offered. TIA!

 

[Spare time]

A pH of 7.4 is impossible in a reef tank (unless you injected some insane amount of carbon dioxide). Don't use a pH boosting additive unless you are trying to dose to alkalinity (and sometimes alk+calcium in the same product) at the same time as they are the same thing. You need a better pH test if you are concerned.

pH is determined by the ambient carbon dioxide levels (and in turn the amount of hydrogen ions in a solution). If a tank has a solid lid, this will hinder gas exchange and result in a lower pH, same with low surface agitation. However, the room also needs to be well ventilated (such as having an open window) to allow the levels of carbon dioxide in the room to not be elevated (as is common indoors). Alternative ways to raise pH would be an algae scrubber or refugium that consume carbon dioxide, dosing a high pH alk additive (soda ash for example) if alk consumption calls for dosing, or running a carbon dioxide scrubber (which is more complicated than the first two).

 

[1979fishgeek]

I test a lot of hobbiest water at work and used to think pH under 7.8 was impossible, but it’s definitely not. I’ve tested water (triple checking) and had a lot of tanks running in the mid to low 7s like 7.4 or 7.6 and even one at 6.4!

It’s a head scratcher for me what causes it to drop that low, I often suggest opening a window in the room the tanks in if it’s winter time as co2 can build up in homes with all the doors and windows shut causing the Ph to drop. Also putting a co2 scrubber on the air inlet to a skimmer or even running the tube through a wall outside might help this as well.

In many of the cases Alk is high and the customers say they don’t dose anything, but once that PH drops I believe it’s actually dissolving the substrate and rocks not to mention coral skeletons.

Adding Kalk to ATO can do wonders, as it increases the Ph but also the Alk and Calc too.

I’d love to hear the science behind marine water pH being so low. In some cases I think a increase in organic’s might also contribute but in some of the tanks I’ve tested nutrients are really quite low.

Considering the effort I used to put into making RO water acidic for breeding various black water fishes in the past using peat and sphagnum moss it’s quite surprising how it happens in tanks so full of calcium carbonate.

 

[Spare time]

I test a lot of hobbiest water at work and used to think pH under 7.8 was impossible, but it’s definitely not. I’ve tested water (triple checking) and had a lot of tanks running in the mid to low 7s like 7.4 or 7.6 and even one at 6.4!

It’s a head scratcher for me what causes it to drop that low, I often suggest opening a window in the room the tanks in if it’s winter time as co2 can build up in homes with all the doors and windows shut causing the Ph to drop. Also putting a co2 scrubber on the air inlet to a skimmer or even running the tube through a wall outside might help this as well.

In many of the cases Alk is high and the customers say they don’t dose anything, but once that PH drops I believe it’s actually dissolving the substrate and rocks not to mention coral skeletons.

Adding Kalk to ATO can do wonders, as it increases the Ph but also the Alk and Calc too.

I’d love to hear the science behind marine water pH being so low. In some cases I think a increase in organic’s might also contribute but in some of the tanks I’ve tested nutrients are really quite low.

Considering the effort I used to put into making RO water acidic for breeding various black water fishes in the past using peat and sphagnum moss it’s quite surprising how it happens in tanks so full of calcium carbonate.

I thought it was very difficult because the sand, rock, and coral would be dissolving at such a low pH. I thought they act as a buffer and would prevent such low values. @Randy Holmes-Farley am I missing something? I thought this was what you have mentioned before but I want to double check. I read on another thread 7.5 was the lowest that a normal reef tank may get to.

 

[Randy Holmes-Farley]

I thought it was very difficult because the sand, rock, and coral would be dissolving at such a low pH. I thought they act as a buffer and would prevent such low values. @Randy Holmes-Farley am I missing something? I thought this was what you have mentioned before but I want to double check. I read on another thread 7.5 was the lowest that a normal reef tank may get to.

Maybe that pH 6.4 was not a reef tank and did not have any calcium carbonate in it. Or it was not accurate.

The only way anyone is going to get to low pH like that is if alk is very low (say, less than 2 dKH) and there is no CaCO3 to dissolve.

 

[Randy Holmes-Farley]

I am about to fire up my BioCube 16 tank this weekend or next. I have two Ocellaris Clowns (tank raised for the past 7 years) that I intend to transfer to the bioCube. For the past 7 years, they have lived in a 10-gallon tank that has a trickle filter built in, along with a couple of small Hermit Crabs. Granted, I have not done water changes near as often in this tank as I should have (usually like one gallon per month), but the Clowns have done fine, eat like pigs, and are about 3 inches long.

I decided this morning to test the water in the 10-gallon tank using my new API Saltwater Master Test kit. As I figured, the Ammonia level and Nitrite levels were zero. The Nitrate level was high, 160 ppm. I had a feeling the pH would probably be low, and it was, only 7.4 ppm. I'm concerned as to what to do to get the Clowns used to a higher pH.

I don't know at this point if a water change is what I should do or not. The clowns have been living in this low-pH level tank for years, and by all accounts seem fine. I know that when I put in the water for the BioCube, the pH level should be acceptable (I am buying seawater from my LFS). Should I do some kind of slow drip acclimation to adjust the pH on the clowns from 7.4 to the pH of the seawater I am buying for my BioCube? I haven't asked the folks at the LFS what the pH level is of the seawater they sell, but I am fairly sure it is acceptable. If I went this route, how long should I take doing a drip acclimation to bring the pH up for the clowns before putting them in the BioCube? I have also seen a product called Proper pH 8.2 Powder. Has anyone used it? Would this be a good way to raise the pH in the 10-gallon tank to get the clowns used to a higher pH?

I can promise you that I certainly will not allow the pH (and nitrate) levels to get out of line with the BioCube once it is up and running. I am grateful for any assistance that is offered. TIA!

If nitrate is very high and you have never measured and maintained alkalinity, the super low alk might be your issue. pH directly relates to the alkalinity.

First step: measure the alkalinity .

 

[John J in Pickens]

Maybe that pH 6.4 was not a reef tank and did not have any calcium carbonate in it. Or it was not accurate.

The only way anyone is going to get to low pH like that is if alk is very low (say, less than 2 dKH) and there is no CaCO3 to dissolve.

The 10-gallon tank's pH is actually 7.5 (I tested it again this morning.) I understand this is still way too low. I think if I had done regular water changes over the past 7 years it has been running, the pH would likely be closer to normal range. This 10-gallon tank has only been used to house the two Oscellaris Clownfish and 3 hermit crabs that will go into the BioCube 16, as soon as I have it running and cycled. Then, I intend to break down the 10-gallon tank and sterilize it and use it as a hospital/quarantine tank.

 

[YOYOYOReefer]

I bet the 6.4 sample came from a calcium reactor. . At PH= 6.4 no typical reef tank corals will live

 

[Briansreef]

PH has been my biggest battle. PH runs 7.8 with outside air source to high volume pump with micro bubblers and my skimmer. Chaeto to help at night and Kalk for my Alk and calc. I’ve tried house plants next to tank and co2 scrubbers all at once 7.8. On a good day when windows can be opened too I get to 8.0. Tested with a calibrated Hanna meter. Good luck in your ph battle.

 

[Randy Holmes-Farley]

The 10-gallon tank's pH is actually 7.5 (I tested it again this morning.) I understand this is still way too low. I think if I had done regular water changes over the past 7 years it has been running, the pH would likely be closer to normal range. This 10-gallon tank has only been used to house the two Oscellaris Clownfish and 3 hermit crabs that will go into the BioCube 16, as soon as I have it running and cycled. Then, I intend to break down the 10-gallon tank and sterilize it and use it as a hospital/quarantine tank.

Yes, that is a believable number. The pH 6.4 I was referring to was posted by fishgeek above.