Hiya, i came home after a coldish day and when i went to check on my pond 12 of my 24 goldfish were dead. I have a 400 gallon pond that i just instaled like two weeks ago, and when i checked the water the ph was 6! Everything else was normal, so did the ph or the cold water kill my fish? And was i overcrowding the new pond?
Sorry for all the questions but how many fish should i put in my pond for now? And what can i do to save my other fish?

Sorry for all the questions but how many fish should i put in my pond for now? And what can i do to save my other fish?
