Hi, my name is Rose and my husband and I have a 30 gallon tall tank with 2 placostemus' and as of right now we have 1 fantail and a regular white and gold goldfish. Anyways 2 have died from internal bleeding. How do I know this? Well the one after he died I left him lay out on a paper towel and after a while he just started bleeding from underneath his skin. Before he died he started staying at the top of the water above the bubble curtain in the back sucking up all the bubbles he could. Anyways the last 2 fish that died did the same things now this white and gold goldfish is doing it too. What is causing this??? We bought some test strips and the people told us to stop feeding them for a few days so we did and the ph levels and all that went to normal well now they are back to sky high again and we just dont know what to do.