I've read that an airstone should be kept running to keep the water well oxygenated, but i give CO2 to my water and airstone cannot be run all the time because it defeats the purpose of giving CO2 as CO2 escapes the from the surface. Now i'm running the airstone only when the light goes out, all night that is (about 14hrs). But i'm concerned about the pH swings, i've read at many places that pH swings are very bad for Discus.

Will the pH swings in my case be harmful to the fish?
Will the Oxygen given by the plants be enough during daytime?

picture of my tank to assist your answers..



I have 8 juveniles in my 55G now along with 4 kuhli loaches and 3 apple snails.