[fish878]

I can't get my ph below 6.9. I have an automated co2 system and a water kh of 3. When I first got my co2 system I could lower the ph in a matter of minutes. Now I can't get it below 6.9 despite having my regulator and bubbles per second cranked to the max. I've also tried replacing the tubing running from the reactor to the regulator. Any suggestions?

 

[OverThinker]

Couldn't you add some peat?

 

[airborne_r6]

Why are you trying to lower the pH? Are you trying to get the CO2 concentration up?

 

[j-gens]

have you checked your water stats lately?

 

[Left C]

Something is rotten in Denmark.

- Have you calibrated your probe lately?

- Is the probe bad? They only last about a year (give or take).

- Is there a leak somewhere?

 

[Church]

...Or do you have something in the tank that is buffering the pH? Limestone, crushed coral, etc.?

 

[calfish64]

This may sound silly but one time I had leak on the bubble counter so the PH never got lower even when I cranked up co2 all the way.

You can try to put tank water and probe in a cup and bubble co2 into it. The ph reading should go down quickly. From there you should be able to isolate the problem.

 

[smoq]

I still wonder why you want to lower ph even further. I think ph6.9 is optimum for planted tanks

 

[justin182]

like smoq said, why would you lower the pH any further? is it for your fish?

 

[fish878]

Okay, it looks like a bad probe. I've only had it for about 3 months so I didn't want to think that was the issue. I was trying to get a ph of around 6.7 because I have some unusually soft tap water in my tank. Thanks everyone.