Increase of acidity

[bjkalley]

Hi,

I use (or should say was using) a pH controller to regulate my aquarium's CO2 levels. I realized that my drop checker was blue although the pH is lower than 5. Also no pearling from plants. So first I thought the pH probe was dead, I checked tap water but the device showed 7.3. Then I aerated aquarium water and measured pH, it became 5.3. So there is something in water which reduces the pH of water other than carbonic acid. The substrate is inert, it is not organic like amazonia etc. There is no driftwood, roots etc.. I just give 5ml of tropica specialised nutrition with a dose pump everyday to the 250 liter tank. kH is around 1, so even a weak acid can create a huge drop. I think this acid comes from processes like nitrification. In that case how can I use pH controller reliably to control co2? For now I switched to timer and counting co2 bubbles.

Have a nice weekend.

Kind regard,

 

[hypnogogia]

I realized that my drop checker was blue although the pH is lower than 5

Drop checker is independent of pH in tank.

In that case how can I use pH controller reliably to control co2? For now I switched to timer and counting co2 bubbles.

Many would say that pH controller isn’t reliable. However one way of doing it is setting your controller slightly lower than your morning pH. That way, when plants start photosynthesising and pH rises, the controller will be triggered and turn on CO2. This approach will not give you a 1pH drop though.