Koi Pond Care
Koi Pond pH
Pond PH is only a measurement of the free Hydrogen ions in the water and is very, very dynamic. Your pond pH can change overnight...In particular, your pond pH is prone to fall, and "crashes" are quick, and fatal. Interestingly, many people say they checked their pH last week, and are surprised to find that their pond pH changed overnight.In simple terms, the pH in your koi pond is supported in range by the carbonate activity of the water (measured in Total Alkalinity) and when the carbonates are exhausted, or overloaded, your pond pH plummets to 5.5 and kills your pond filter bacteria and koi. In other situations, your pond pH can glide downward very slowly over months and thus your resident koi can survive a low pH but your new koi you keep buying perish quickly as they enter your koi pond water with a very acid pH.
Check the pH in your koi pond regularly, and also, to get a grip on your 'safety net', measure your pond water's carbonate activity as Carbon Hardness (KH) as well.