Hi guys, I'm after a cheap substrate for a coldwater tank and i thought of Akadama. I understand it changes the water perameters initially so I wondered if my goldfish would have a problem with that? Unfortunatly, I can't house them elsewhere and i'm considering changing this to a tropical tank once they pass away. The tank is not planted apart from a couple of huge Java Ferns. Currently running th tank bare bottom as something in the substrate decided to start killing fish. Failing this route its going to be getting inert gravel of some description. Whats your thoughts?