pH dropping

[Mikedel]

I was wondering what factors would cause pH to drop. Since my tank has been set up the pH has been at 8.3. I check it today and it is in the mid to high 7's. I thought maybe my top off water had a low pH, so I tested it and it was 8.3. What could have caused it?

 

 

Thanks,

Mike

[tinyreef]

low pH can be from overnite respiration, i.e. no photosynthesis occurring to reduce available CO2.

 

it can also come from organic acids released/converted from decaying bio-mass, i.e. dead stuff or too much poo.

 

too much CO2 can triggered low pH. this can come from the ambient atmosphere, too many newly added livestock, and artificial manipulation (e.g. club soda, acids, etc.).

 

have you changed anything lately? new additions, additives, salts, water sources, etc.? the change can even be from batch to batch, e.g. new bag of the same salt, new bottle of water for wc's, and so on. hth