pH dropped to below 7

disaster999 · Sep 27, 2024

My tank has been suffering from low pH for a while now...it kind of started out of nowhere a while back where the pH dropped off a cliff one day from 8.1-8.2 daily to just around 7.5-7.8 seemingly overnight. I didnt do anything different either.

Ive tried to open my windows as much as possible but with 35c and 70%+ humidity in peak summer its unbearably hot at home and my chiller is having a hard time keeping up. Ive added a fan to help with evaporative cooling and hoping it would help oxygenate the water and bring up the pH but it doesnt seem to help. The increased evap means i have to dose more kalk to my system which wrecked havoc on the alkalinity in the system and shot way up to 11dkh+. Dosing pH buffer was just as bad as its only a momentary fix and it jacks up my alkalinity. The pH have been on a downhill slope since that initial drop and its gotten as low as 6.9 at nights. Ive added a CO2 scrubber and that only brought it up to 7.89 at its highest before exhausting its usefulness in less than a week. I could keep changing out the media but its not that sustainable in the long run.

Ive read about keeping a fuge which would help convert the CO2 to O2 in hopes it would help raise the pH, but thats a big hope considering it need to raise it to 1 full point to where it is now Its something I should add to my tank but it takes time in designing and building for my setup. What else can I do to help raise the pH as much as possible?

Garf · Sep 27, 2024

disaster999 said:
My tank has been suffering from low pH for a while now...it kind of started out of nowhere a while back where the pH dropped off a cliff one day from 8.1-8.2 daily to just around 7.5-7.8 seemingly overnight. I didnt do anything different either.

Ive tried to open my windows as much as possible but with 35c and 70%+ humidity in peak summer its unbearably hot at home and my chiller is having a hard time keeping up. Ive added a fan to help with evaporative cooling and hoping it would help oxygenate the water and bring up the pH but it doesnt seem to help. The increased evap means i have to dose more kalk to my system which wrecked havoc on the alkalinity in the system and shot way up to 11dkh+. Dosing pH buffer was just as bad as its only a momentary fix and it jacks up my alkalinity. The pH have been on a downhill slope since that initial drop and its gotten as low as 6.9 at nights. Ive added a CO2 scrubber and that only brought it up to 7.89 at its highest before exhausting its usefulness in less than a week. I could keep changing out the media but its not that sustainable in the long run.

Ive read about keeping a fuge which would help convert the CO2 to O2 in hopes it would help raise the pH, but thats a big hope considering it need to raise it to 1 full point to where it is now Its something I should add to my tank but it takes time in designing and building for my setup. What else can I do to help raise the pH as much as possible?

You sure the pH probe is good?

disaster999 · Sep 27, 2024

Garf said:
You sure the pH probe is good?

Thats another thing Im checking. Ive cleaned and calibrated a few times and the numbers didnt change much. Ive checked my kalk solution and it reads over 12pH, Tap water is slightly lower than 7. I have another prob and more calibration solution coming to ensure the probe I have is good.

gbroadbridge · Sep 27, 2024

disaster999 said:
My tank has been suffering from low pH for a while now...it kind of started out of nowhere a while back where the pH dropped off a cliff one day from 8.1-8.2 daily to just around 7.5-7.8 seemingly overnight. I didnt do anything different either.

Ive tried to open my windows as much as possible but with 35c and 70%+ humidity in peak summer its unbearably hot at home and my chiller is having a hard time keeping up. Ive added a fan to help with evaporative cooling and hoping it would help oxygenate the water and bring up the pH but it doesnt seem to help. The increased evap means i have to dose more kalk to my system which wrecked havoc on the alkalinity in the system and shot way up to 11dkh+. Dosing pH buffer was just as bad as its only a momentary fix and it jacks up my alkalinity. The pH have been on a downhill slope since that initial drop and its gotten as low as 6.9 at nights. Ive added a CO2 scrubber and that only brought it up to 7.89 at its highest before exhausting its usefulness in less than a week. I could keep changing out the media but its not that sustainable in the long run.

Ive read about keeping a fuge which would help convert the CO2 to O2 in hopes it would help raise the pH, but thats a big hope considering it need to raise it to 1 full point to where it is now Its something I should add to my tank but it takes time in designing and building for my setup. What else can I do to help raise the pH as much as possible?

Sounds like a measurement error.

I'd clean the probe if you haven't already.

crazyfishmom · Sep 27, 2024

I would consider the Hanna pH checker. It’s a good sanity check piece of equipment to have when pH goes outside the typical range and you’re using a pH probe. I don’t trust pH probes at all.

Randy Holmes-Farley · Sep 27, 2024

pH below about 7.5 is not typically accurate.

Try this aeration test, which will evaluate both the calibration/probe function and the extent of CO2 issues, if any:

https://www.reefedition.com/ph-and-the-reef-aquarium/
The Aeration Test

Some of the possible causes of low pH listed above require an effort to diagnose. Problems 3 and 4 are quite common, and here is a way to distinguish them. Remove a cup of tank water and measure its pH. Then aerate it for an hour with an airstone using outside air. Its pH should rise if it is unusually low for the measured alkalinity (Figure 2). Then repeat the same experiment on a new cup of water using inside air. If its pH also rises, then the aquarium’s pH will rise simply with more aeration because it is only the aquarium that contains excess carbon dioxide. If the pH does not rise in the cup (or rises very little) when aerating with indoor air, then that air likely contains excess CO2, and more aeration with that same air will not solve the low pH problem (although aeration with fresher air should). Be careful implementing this test if the outside aeration test results in a large temperature change (more than 5°C or 10°F), because such changes alone impact pH measurements.