OK, so Valentino (bought 2-14-11) can from a very dirty little bowl in the pet store we just found. He was a bit skittish in the bowl, but is very pretty so I bought him anyway. Got him home and slowly introduced him to his new tank, he seemed fine, was somewhat friendly towards us, but spent a lot of time pacing the back of the tank. He was eating, but not as well as the other fish. We got him a new heater, the old one was one of those "betta" heaters that only increase the room temp by 5 degrees. We kept the house a warmer 70 for the couple of days waiting for the new heaters to come in. We slowly brough his temp from 75 to 79 and then he stopped eating. He'd try a bit then spit it out. Even the worms were spit back out.
Oliver who was bought from a different pet store on 2-12-11 was your typical hyper begging for food every time he saw a shadow type fish. He had the same betta heater and his tank was also 75 and is now 79. Same thing, slowly introduced him to his home, he LOVED it. He was super friendly and fun to watch.
I did water changes on all three tanks, added the conditioner even though we have well water with no chlorine. (it's been tested and everything is fine) Everyone seemed fine and ate their worm treats.
Last night we came home from work and Oliver and Valentino were just sitting at the tops of their tanks. Barely breathing. Not much gill movement. We noticed that Oliver has foggy eyes, like a blind animal has. His eyes were crystal clear that morning. We skipped their dinners as neither were eating.
This morning the same thing. Both are still floating and not breathing much and no gill movement. No eating again. No response when we come up to the tank. I tried to stick my finger in Valentinos tank and could actually pet him very lightly and he wouldn't move. He finally would move up to breath but that was it.
Aside from the heaters nothing is different. It wasn't a drastic temp difference only from 75 to 79 and it took 4 hours to do it.
Is this just bad luck and the new fish were most likely sick? It really can't be something with the heaters can it? The third tank has the same heater, although over a year older. When we switched that tank from the betta heater to the new one he was fine and it didn't phase him at all. He had the same water change. The same readings. Same temp. Same everything.