Originally Posted by Fiki
What I want to say is that, due extremely low buffer capacity such as kH zero, pH value simply can not be stabile, especially if you use pressurized CO2 at the same time. Therefore, I've been trying to avoid often fluctuation of pH caused by buffer insufficiency in aquarium water, as they can cause a lot of problems regarding the fishes health and possible stress. In addition, I would appreciate if you could make a short list of aquatic plants and fishes that you successfully grow at KH zero, using the CO2 injection at the same time.
Personally, I am not sure if the CO2 tables we use are correct. After spending years chasing KH, CO2 and pH I found easier way. No KH buffering, no pH testing and no sick fish and plants. Actually, fish are much happier and plants grow even healthier. The plant list includes several dozen plant species from Echinodorus and Cryptocoryne to Wallichii and Toninas. Never had a plant that wouldnít like it. Lower the KH nicer the plant.
Fish I have are Tetras, Angels, Altums and Discus, naturally soft water fish. Brackish and Tanganyikan Cichlids are not compatible of course.
Generally fish donít like pH changes and high CO2. The actual pH doesnít matter. CO2 is natural to the fish. It creates stability at pH ~ 5.6. It never goes bellow 5 or so. (As an experiment I added peat moss to lower it even more, bellow CO2 capacity of 5.65 to 3.7 and still no problem)
We can not stress more the need to use CO2 only. No other acids are safe.
If you see your fish in stress or dead then it is due to high CO2, poison or non CO2 acid.
Originally Posted by banderbe
Hi Edward. How do you avoid the dreaded pH crash? Or is that just another myth?
Can you define such crash?
What we see is CO2 overdose not pH crash. It is the CO2 killing the fish not the low pH.
Tropical rainy season removes carbonates (KH) buffering and takes large amounts of humic and carbonic (CO2) acid. Are there casualties because of some pH crash? No.
We shouldnít be afraid exploring more natural approach growing fish and plants in our aquariums.