Co2 Question

[xxblackatlasxx]

Good Morning everyone,

I am still within my first 6 months of the hobby and was wondering a few things. Let me start off by saying that I know that you are not supposed to chase pH. Ok now that that is out of the way.

I have noticed that my my pH on my apex and my manual test kits read about from 7.5 - 7.7. I am doing a mixed system with fish and coral. I have tried the method of a co2 scrubber as well as running a fresh line out the window to pull in fresh air.

I might be crazy, but is it possible that my home does not have much c02 to exchange with the oxygen so there is not much to diffuse. There is only about 11 fish currently in the 130 gallon tank.

Thanks again for any advice. If this is a silly thought people let me know.

Atlas.

 

[ca1ore]

The first thing to check with pH is whether your measurement devices/kits are accurate. 7.5 is very low for a reef tank. The second thing to check is your alkalinity. If that is low, raising it should also raise pH. Do you run a CaRx? If not, and alk is within range, then the only likely culprit is ambient CO2 levels. A CO2 scrubber/fresh air works for some people, but not others (it does not work for me). Opening a window might help - though that becomes problematic as the outside temp/humidity rises.

 

[SinCityRee4r]

In my opinion I run a co2 scrubber with airline outside. I did make my PH more stable and a bit higher. What made the biggest difference was increasing my turnover rate. I used to run at about 550GPH. I am now running over 700GPH and my PH haze increased by 9-10. I also Installed powerheads agitating water surface to help with co2 gas exchange. Maybe one of these solutions will help your issue also. Good luck and Happy Reefing.

 

[xxblackatlasxx]

The first thing to check with pH is whether your measurement devices/kits are accurate. 7.5 is very low for a reef tank. The second thing to check is your alkalinity. If that is low, raising it should also raise pH. Do you run a CaRx? If not, and alk is within range, then the only likely culprit is ambient CO2 levels. A CO2 scrubber/fresh air works for some people, but not others (it does not work for me). Opening a window might help - though that becomes problematic as the outside temp/humidity rises.

I am a little lower on the alkalinity scale. Around a 8.2ish. I think the range is 8 - 11. I don't currently use CARX, but I bought some kalkwasser at one point to help bring my alkalinity up. I was told by the store not to use it though because my Calcium was slightly over 500. Since the range for this is 400 - 450. They told me to let this fall on it own as it used up by my tank. I tried opening a window because I bought the scrubber. It didnt really seem to help.

 

[xxblackatlasxx]

Could the problem also be my tank is under stocked? The largest fish that I have is approximately a 4ish-inch yellow tang. So he is still a juvenile. 6 firefish, 1 blue damsel, 1 3-inch tomini tang, and two small wrasse.

 

[ca1ore]

More fish = more released CO2 …. so all things equal, lower stocking usually means higher pH. Take a sample of your water, aerate it for a while outside and then measure the pH. That will tell you whether there is a CO2/carbonic acid issue. If there is, then some additional descriptions of your system would help us to help you.

 

[AZRipp]

Be sure you have good air exchange over the top of the tank's water surface. Water agitation and gentle air flow helps. Just be aware that stronger airflow can lower the tanks temperature. I actually use this technique to control my tank's temperature. Your ALK at 8.2 shouldn't be the problem, but slowly raising it may help. I would be curious to see if things improve simply getting it closer to 9. As ca1ore stated, definitely make sure your testing device (Apex with Probe - "calibrated") and test kit are accurate before getting too spun up.

 

[BestMomEver]

Be sure you have good air exchange over the top of the tank's water surface. Water agitation and gentle air flow helps. Just be aware that stronger airflow can lower the tanks temperature. I actually use this technique to control my tank's temperature. Your ALK at 8.2 shouldn't be the problem, but slowly raising it may help. I would be curious to see if things improve simply getting it closer to 9. As ca1ore stated, definitely make sure your testing device (Apex with Probe - "calibrated") and test kit are accurate before getting too spun up.

I put a small fan up so it can blow across the top of the water. The goal was to stop the mildew forming in my canopy. One of the other things it did was raise the pH.

 

[xxblackatlasxx]

I will get some more ph probe calibration fluid and re-calibrate it. I have a fan blowing across the sump for the purpose of cooling when it the water temperate starts to rise. I have an apex powerhead on each end of the tank. I think my surface agitation is pretty good.

More fish = more released CO2 …. so all things equal, lower stocking usually means higher pH. Take a sample of your water, aerate it for a while outside and then measure the pH. That will tell you whether there is a CO2/carbonic acid issue. If there is, then some additional descriptions of your system would help us to help you.

So after I take some water out of my face and aerate for a bit what kind of results am I looking for. What type of descriptions would you like?

 

[AZRipp]

So after I take some water out of my face and aerate for a bit what kind of results am I looking for. What type of descriptions would you like?

You're just looking to see if the pH comes up showing that there was a concentration of CO2 in the water. It will naturally come up, but if it raises significantly, it's showing there was an over concentration. (I believe that is waht ca1ore was getting at.)

 

[ca1ore]

Correct. Aerating a water sample outside will give you a sense of how much of your low pH is a result of high CO2 concentrations. If your tank is at 7.8, but after aerating you get to 8.2, you'll know it is a CO2 problem. Then it's a matter of working out where it's coming from. Is your sump sealed up in the stand for example where some input of fresh air might help. Is your tank 'marinating' in an internal environment high in CO2 (this is my issue)?

 

[xxblackatlasxx]

Thanks everyone. I will try this later today when I get home. And when you say aerate, can I just use a air pump with a wood stone on it. or what do you recommend?

 

[AZRipp]

... when you say aerate, can I just use a air pump with a wood stone on it. or what do you recommend?

That or simply put the airline in the container of water for awhile.

 

[xxblackatlasxx]

So I did a manual test and this is the result. The one on the right is water directly from my aquarium. The one on the left is after I aerated it for about a hour completely outside on my screened in patio.

It appears to be exactly what you guys said it is. I have a issue with co2 in my tank. And it is bringing my ph down. My sump in not in a sealed area. It's open in the back. Like I said earlier I have to of the apex powerheads located in the top half of the tank. One on each side.

My tank is in my office. I dont think this area is a place where there is a high concentration of co2, but I could be wrong. That's why I bought the co2 scrubber to assist in this, but I guess it is not working. I might need to run this air stone in my sump for more oxygen exchange.

 

[xxblackatlasxx]

So it looks like my surface agetation is good. Maybe I need to tilt my powerheads more towards my rocks and less at the surface. Maybe the pockets of co2 are around the rocks.

 

[AZRipp]

OK, that's odd. What is your Mag level? It's not going to do anything for pH, but curious since your CA is so high. Since your CA levels are high, I would make sure your Mag level is 1400+ and slowly start increasing your Alk level closer to 9 over a few days. What are you testing your Alk/CA/Mag with?

 

[xxblackatlasxx]

OK, that's odd. What is your Mag level? It's not going to do anything for pH, but curious since your CA is so high. Since your CA levels are high, I would make sure your Mag level is 1400+ and slowly start increasing your Alk level closer to 9 over a few days. What are you testing your Alk/CA/Mag with?

I just saw this. My Mag is around 1350. I am using a Salifert test kit for Alk/CA/Mag. I can retest it when I get home today. I was supposed to do my weekly water test yesterday, but got busy with chores around the home.