HD: But I see jonathan's tank seems lack of biological filtration, that's why I told him.
TBTB: He does not have a bio filter, is that what you are saying?
HD: My main tank, got 5.5-6 pH in it, my tap water around 7.5-8 pH.
So I try to manipulate it as natural as possible, that's why I put 60 kg ceramic sponge ring media in my 220 gallon tank filtration system (my sump is around 80 gallon), IME they did great to maintain pH, keep it at 5.5 to 6.
TBTB: IME and AFAIK, ceramic media increases pH slightly. But I too am looking to learn
HD: So I decided to apply the same biological media composition in my 5 other tanks.
And the result was same, so I keep it like that.
TBTB: How long has it taken for the pH to go to 5.5-6 from 7.5-8? Does the pH jump up after you clean the filters?
HD: If you know the scientific reason on this, correlation between biological filtration and pH maintain, I want to know, and I am very grateful for the information, for me, it just result of many2 tempts, trials and errors.
TBTB: My understanding is that all by itself, bio media would not change your pH or buffer it. The accumulation of detritus acidifies water. Certain balance of aerobic and anaerobic bacterial activity can shift the pH too but the effect may be convoluted, hard to predict. When one sees CO2 (carbon dioxide) bubbles produced in their filter, that should be accompanied by an acidic shift in pH because CO2 is acidic CO2 + H2O = H2C03 - carbonic acid. Many say this is an indication that filter is overdue for cleaning.