Why doesn't my PH rise above 8?

[BigHildy53]

I have a CO2 scrubber, and that used to raise my PH to 8.3. Now my PH only goes to 8. It will drop to 7.6 when the skimmer is off for a few hours. I've checked for airline leaks which may bypass the co2 media. I have a 180g display. The CO2 media is in two BRS jumbo reactors. I use a container with water as the air input to the canisters. I believe there is an ample amount of surface agitation. The house has one adult, two children and two dogs. I dose BRS alk and calcium. Any ideas as to why the PH just won't go above 8?

Alk 9.7
Phosphate .5
Nitrates 25
Nitrite 0
Ammonia 0
ORP 450

 

[hijinks7]

Your co2 media needs to be replaced?

Your ph probe (if you use one?) needs to be re-calibrated or replaced?

 

[chipmunkofdoom2]

Surface agitation will not help with pH unless the air around your tank has less CO2 than the air in the tank. Surface agitation creates an interface between your tank and the air where gas exchange can occur. This will only lower your CO2 (thereby raising your pH) if the air around your tank has lower CO2 than your tank does. If the air around your tank has more CO2 than your tank does (which sounds like the case since pH drops when you turn off the skimmer), surface agitation is going to increase CO2 and decrease pH, not the other way around.

Note that I'm not advocating against surface agitation in general. However, if you want to raise pH and you have CO2 problems, it's not going to help you.

 

[ELChingonsReef]

I'm having the same exact problem..im at work all day..I can't leave windows open when I'm not home. My ph is always 7.8 all day until I get home and open the windows then it only gets to about 7.9. This is with a co2 reactor. I have a 65 gallon reef . No matter what I do I never see 8.3 ph.

 

[LRT]

Agreed pounding co2 rich air back into system is counterproductive. I dont run the co2 media i ran my skimmers air lines outside instead. Co2 media needs to be replaced?
Do you have co2 monitor to check levels?
Hows your humidity?
I'm finding with co2 around 4-600 im perfectly good with tons of surface agitation, skimmer lines ran outside in sitting around 8-8.2.
Soon as my humidity rises around 50% my ph begins to lower on me.

 

[Randy Holmes-Farley Verified Community Expert]

I'm having the same exact problem..im at work all day..I can't leave windows open when I'm not home. My ph is always 7.8 all day until I get home and open the windows then it only gets to about 7.9. This is with a co2 reactor. I have a 65 gallon reef . No matter what I do I never see 8.3 ph.

pH 8.3 is not any special goal, IMO. I wouldn't agonize over it if it is in the pH 7.8 to 7.9 range.

Raising it could involve using higher pH alk additives, if you wanted, along with fresher air tot eh tank, or a scrubber.

 

[Aeb1419]

I saw the thread and I am curious about the concerns with regards to pH. Not that we shouldnt have but I havent tested my pH for about a year now with no concerns. Corals and fish look fine. Does everyone do this with regards to something that is happening/immediate concern or is this a chasing numbers game?

I am generally interested because I hear people growing corals at an amazing rate and my coral growth seems rather slow. Could pH be the factor?

 

[Randy Holmes-Farley Verified Community Expert]

Does everyone do this with regards to something that is happening/immediate concern or is this a chasing numbers game?

Does it need to be one or the other?

Low pH does make it harder for some organisms to calcify.

pH below 7.7 is a more serious concern as skeletons can even slowly dissolve.

 

[mdb_talon]

I saw the thread and I am curious about the concerns with regards to pH. Not that we shouldnt have but I havent tested my pH for about a year now with no concerns. Corals and fish look fine. Does everyone do this with regards to something that is happening/immediate concern or is this a chasing numbers game?

I am generally interested because I hear people growing corals at an amazing rate and my coral growth seems rather slow. Could pH be the factor?

Many corals do grow faster at a higher PH yes. Have read many studies and it is hard to quantify how much. Whether it is worth "chasing numbers" i dont know....but personally i find in a completely unscientific study of my own tanks i get much faster growth at 8.2-8.3 than at 7.8-7.9.

 

[Aeb1419]

Thanks for the input. I think maybe I should start monitoring ny pH. Haha

 

[ELChingonsReef]

pH 8.3 is not any special goal, IMO. I wouldn't agonize over it if it is in the pH 7.8 to 7.9 range.

Raising it could involve using higher pH alk additives, if you wanted, along with fresher air tot eh tank, or a scrubber.

I'm using a co2 scrubber. I used a phosban 150 filled it with the brs media . I'm using a eshops 120 skimmer. It doesn't seem to suck much air though. I would need 15 feet of tubing to run a fresh air line outside I don't think that small skimmer would be able to get the air it needs from a 1/2 inch line 15 feet long. Im considering using reef buffer even though people tell me I shouldn't do that. What's your opinion on reef buffer for ph . I have a 65 gallon tank with a 20 gallon sump probably running 55 gallons of total water alkalinity is at 8.7 PH is at 7.5 phosphate 0.3 calcium is at 493 magnesium is at 1345 nitrates are at 15 I run 3 reactors for carbon phosguard and biopellets because I don't have a refugium. That's my system in a nutshell. I probably have too much live rock for my 65 gallon tank my calcium is always high.

 

[mdb_talon]

I'm using a co2 scrubber. I used a phosban 150 filled it with the brs media . I'm using a eshops 120 skimmer. It doesn't seem to suck much air though. I would need 15 feet of tubing to run a fresh air line outside I don't think that small skimmer would be able to get the air it needs from a 1/2 inch line 15 feet long. Im considering using reef buffer even though people tell me I shouldn't do that. What's your opinion on reef buffer for ph . I have a 65 gallon tank with a 20 gallon sump probably running 55 gallons of total water alkalinity is at 8.7 PH is at 7.5 phosphate 0.3 calcium is at 493 magnesium is at 1345 nitrates are at 15 I run 3 reactors for carbon phosguard and biopellets because I don't have a refugium. That's my system in a nutshell. I probably have too much live rock for my 65 gallon tank my calcium is always high.

Reef buffer is just adding alkalinity. It is fine if you want to raise alk, but if you want to raise PH and not alk then it probably does not make sense to use. Some alk products are going to raise PH more than others and in my experience the products marketed for increasing PH are not always the best at actually increasing PH.

 

[jefft0826]

I found a big chunk of salt built up on my Ph probe. I removed it and recalibrated and was back to normal.
What are you using to check ph

 

[ELChingonsReef]

I thought of that too..maybe my pH probe is dirty or needs to be recalibrated. I'm using the apex for my ph probe. I'll check the probe..does anyone know how far down in the water the apex ph probes need to be..I have mine 25% submerged in the sump water because when my return pump stops I herd its not a good idea to have the probe completely under salt water