New Tank - pH Too Low

Rusty Dalton · Jul 20, 2020

I'm setting up a new tank, 25 days since I added Dr. Tim's beneficial bacteria, and my pH continues to be low:

My parameters have been rather stable:

Salinity

34 - 35 ppt

Temp

77 - 78 f

pH

7.4 - 7.6

ORP

340 - 350 mV

Alkalinity

8.9 - 9.1

Calcium

440 - 450 ppm

Magnesium

1250 - 1260 ppm

Any suggestions? I'm running a Neptune APEX & Trident, and I have confirmed the salinity, temp, pH and alkalinity with API and Hanna test kits to make sure the APEX and Trident are accurate and it is.

Alanna102499 · Jul 20, 2020

Can you get some outside air into your skimmer airline? Open windows clean out carbon dioxide around tank with plants. Are you getting enough agitation on the water surface from your return pump and wave makers?

chipmunkofdoom2 · Jul 20, 2020

Take a cup of water and aerate it outside with an air stone for 10 minutes. If the pH is not between 8.1 and 8.3 after that, there's something wrong with your pH probe.

LeftyReefer · Jul 20, 2020

I'd do a water change after the cycle completes, then check it again.

redfishbluefish · Jul 20, 2020

How are you measuring pH? Let me just say it, I don't believe it. Unless you're in a very new house that is tight as tight can be, stop breathing! The major cause of low pH is carbon dioxide.....what we exhale. If those numbers are real, the best way to lower is to run your skimmer intake line outside to get in fresh air. Otherwise, I think you're seeing a crappy pH kit, and the number is bogus. There, I said it!!!

EDIT TO ADD:

Doh! I wish I'd read first before commenting. I see you're running an Apex with a probe. When is the last time you calibbrated with pH 7 and 10 solutions?

proxy001 · Jul 20, 2020

Calibrate probe... There are only so many variables in Ph. and I though mine was low at 7.9
I would double check Ph with a test kit, it won't be super accurate but you will know if range is off

Adam_1992 · Jul 20, 2020

What does your Ammonia, Nitrites & Nitrates look like?

Rusty Dalton · Jul 20, 2020

redfishbluefish said:
How are you measuring pH? Let me just say it, I don't believe it. Unless you're in a very new house that is tight as tight can be, stop breathing! The major cause of low pH is carbon dioxide.....what we exhale. If those numbers are real, the best way to lower is to run your skimmer intake line outside to get in fresh air. Otherwise, I think you're seeing a crappy pH kit, and the number is bogus. There, I said it!!!

EDIT TO ADD:

Doh! I wish I'd read first before commenting. I see you're running an Apex with a probe. When is the last time you calibbrated with pH 7 and 10 solutions?

The house is about 10 years old.

I did a calibration about a week ago on the APEX probe. The API pH test show the same reading as the APEX...

proxy001 · Jul 20, 2020

Do you run a skimmer?

Rusty Dalton · Jul 20, 2020

proxy001 said:
Calibrate probe... There are only so many variables in Ph. and I though mine was low at 7.9
I would double check Ph with a test kit, it won't be super accurate but you will know if range is off

Calibrated and the test kit matches

Rusty Dalton · Jul 20, 2020

Adam_1992 said:
What does your Ammonia, Nitrites & Nitrates look like?

I just tested all three and they are all at 0 ppm

Rusty Dalton · Jul 20, 2020

proxy001 said:
Do you run a skimmer?

Yes, Red Sea RSK-600

Rusty Dalton · Jul 20, 2020

chipmunkofdoom2 said:
Take a cup of water and aerate it outside with an air stone for 10 minutes. If the pH is not between 8.1 and 8.3 after that, there's something wrong with your pH probe.

Doing this right now, stay tuned...

Rusty Dalton · Jul 20, 2020

chipmunkofdoom2 said:
Take a cup of water and aerate it outside with an air stone for 10 minutes. If the pH is not between 8.1 and 8.3 after that, there's something wrong with your pH probe.

Both the APEX probe and the API test kit had the pH at 8.2 after 10 mins with an air stone in the cup of water.

SCiMMiA · Jul 20, 2020

Rusty Dalton said:
Both the APEX probe and the API test kit had the pH at 8.2 after 10 mins with an air stone in the cup of water.

This thread will tell you an easy fix:

This is what happens when you fix co2 in your house

I'm not sure if I am posting this in the right section but let's do it ! I had a lot of problems with corals (almost dying to dying) in the summer time when the AC was turned on into a perfectly sealed house. I had pH drop to 7.6 some times. I read a lot about co2 but I also read a lot about...

www.reef2reef.com

proxy001 · Jul 20, 2020

CO2 in the house. wow, I didn't realize it could make just a difference. You are talking 0.5. I have lowish Ph. But it's Florida, difficult to leave windows opened in the summer and my understanding in that my AC systems just recirculates inside air, no outdoor air intake.
OP, what is your long term plan?

SCiMMiA · Jul 20, 2020

proxy001 said:
CO2 in the house. wow, I didn't realize it could make just a difference. You are talking 0.5. I have lowish Ph. But it's Florida, difficult to leave windows opened in the summer and my understanding in that my AC systems just recirculates inside air, no outdoor air intake.
OP, what is your long term plan?

It's easy, I keep my stove vent hood ON at the lowest setting.
The co2 stays under 1000ppm and pH problems are from the past !

Yes the AC has to work a little more since hot air from outside is reaching inside but it is worth it !