Originally Posted by Karmascapes
Ok so just got back from the water plants farm and got a test kit for ph as well as ammonia levels. The ammonia levels were ok but the ph went straight to blue which according to the card included means at the 9.0 or higher level. I know that isn't good and can kill the fish so what is the immediate recovery method? The water temps are actually staying relatively ok, i am beginning to think it is due to a real lack of O2.
I picked up some water lillies, water lettuce, and something called parrot feathers. They told me one of the best plants to use to produce oxygen is a water hyathicid (?). But they are illegal for some reason here in AR. Any idea about that?
You pretty much ruled out an Oxygen problem in post #3 when you said that the fish were staying in the deepest area during the day. If it was an oxygen problem, they would be at the surface "gasping" or under the waterfall.
A pH of 9.0 seems unusually high, but I know that certain municipalities keep the pH high to prevent corrosion and biofilm buildup in the supply lines. I would double check the accuracy of the pH test kit. Test a sample of water from most any bottled water. It should read somewhere close to 7.0 or alternately, if you can collect some rainfall, test it. It should read between 5.0 and 6.0. Yea, all rain is acid now.
Koi can handle a pH of 9.0, but it is not recommended because anything over this can cause mortality. Adjusting the pH can be more dangerous than leaving it high unless it is done ever so gradually. Koi are great adapters to different environmental conditions, what they are not good at is adjusting to a sudden, sizable change in these conditions. Additionally, ammonia becomes more toxic the higher the pH and the higher the temperature, so any ammonia level detected must be correlated to the existing temperature and pH. On top of all that, nitrifying bacteria function at a much lower level at high pH (9.0+).
I am suspecting that you have possible an ammonia problem or even possible a NitrIte problem from insufficient bioconversion. (Unplugging system overnight, that "smell".)