Maintaining my PH

TankLife87 · Apr 7, 2019

I know this topic has been talked about a lot, but want to be a little more specific for me.

My ph swings from 7.6 down to 7.2 at night. I use the calibrated apex probe to measure this.
I already run my fuge light in reverse cycle.
I do have a canopy and glass tops on the aquarium to prevent jumping suicidal fish.

I read that running an air stone may help as well but there is already so much water bubbling in the sump with the overflow piping in sump.
I keep hearing to run an air stone.. does anyone have ideas on what air stone to run and where to put it?
Is there a brand that works well timing wise with apex?

Crabs McJones · Apr 7, 2019

I would remove the glass tops and replace them with mesh tops. Poor gas exchange is likely what's causing your issue. And while an airstone may help, pointing a powerhead towards the surface will also tremendously help. It could also be CO2 build up in your home. Do you have the ability to open a window or two? Youd be surprised how much your ph will rise from just opening a window. Another option is if you're running a skimmer, run the airline outside to bring in fresh air to the system.

Billldg · Apr 7, 2019

Agree with @Crabs McJones on all points. I personally use mesh tops and also have a canopy on my DT. I wasn't able to run a line outside from my skimmer, so I installed a Co2 scrubber on my skimmer and raised my PH from 7.9-8.05 to 8.15-8.3. I also open the windows to help refresh the air inside my house.

Dkeller_nc · Apr 7, 2019

One other thing to check is whether your calibration for your pH probe is really correct. I don't know your experience level, so ignore this if you already know:

1) It's helpful to equilibrate the pH calibration buffer packets to the tank (and probe's) temperature. Turn the Apex's temperature compensation for pH calibration "on". While measured pH does change with temperature, it's not a massive change, so this is just a "good practice" aspect.
2) It's important to rinse the pH probe off between buffer immersions, and to dry it with a paper towel or something else suitable.
3) pH probes age over time, and at some point require replacement. One clue to whether you need to replace the probe is how long it takes to reach equilibrium in the pH calibration buffer. If it takes longer than a minute or two to reach a stable millivolt value for a particular buffer, it may be time to replace the probe.
4) It's helpful to check the accuracy of your calibration after completion by rinsing off the probe, drying it, and putting it back into the pH 7 buffer. It should read very close to 7. If not, you may have a problem with the calibration procedure, the age of the probe, or both.

And I'd echo what the other posters noted; gas exchange is critical to remove excess CO2 from the system, and if your home is modern and well-sealed, it may be necessary to take steps to inject fresh air by piping it in from outside. And opening a window near the tank and observing the effect on the tank's pH may be your best clue to whether your indoor air is elevated in CO2 concentration.

EMeyer · Apr 7, 2019

Once you have enough gas exchange, adding more does exactly nothing (once water and atmosphere are in equilibrium). If you have a lot of bubbling already from the drain into your sump, you likely are already there. I predict removing glass tops would do nothing unless you are limited on gas exchange.

Do you run a skimmer?

Myself I've never kept a reef in a well-sealed house, so my house PCO2 is pretty much equal to atmospheric PCO2 :) But this sounds like a "run an external airline" scenario.