Reef Angel Forum

So here's my daily pH readings.
pH regularly shows a daily drop from the low 8's to <6 from around 2pm to midnight. Coincidentally, that's the warmest part of the day and matches pretty closely with the activity of the fan blowing across my sump. I also have a Seneye monitor on the tank and its pH readings do not correlate this drop. It shows a more expected curve of pH rising slightly during the day and dropping slightly at night. My tank is doing well, so I suspect that the pH really isn't dropping into the 5's on a daily basis.

I have a theory that the fan blowing across the water may be imparting a static charge to the tank and affecting the pH probe. I put a grounding probe in with no effect (I guess I should check continuity on it to make sure it works).

Any thoughts?

--Colin

I have my fan blowing on the sump water too, but don't have pH drops like you are showing.
I do have a grounding probe in the sump though.

I checked continuity on the grounding probe and I think it may have had a problem. I replaced the plug end, so we'll see how this afternoon goes.

--Colin

I was having the same problem.
I knew there was no way ph was going from 8.3 to almost 7.2 every night.
Ending up being a bad float switch.
So I would think the fan is the culprit.

Did some experimenting yesterday. Grounding probe had no effect. pH reading drops when fan is on (steady drop, not instant) and rises steadily when fan goes off. No drop if fan is on but pointed away from the water.