A few days ago I noticed our cobalt blue dwarf gourami was not looking his best. He didn't come up to eat his food (which is not normal behaviour) and was swimming around near the bottom of the tank. The next morning he was lying on the bottom of the tank, not dead, but not too good either. At the time our flame dwarf was looking fine and swimming around normally. I took out the cobalt and put him in the hospital tank, where he unfortunately died a couple of hours later.
The next day I noticed the flame wasn't looking healthy either!! He'd gone from eating normally, to swimming around listlessly like the cobalt. He's now lying on the bottom of the tank, and I'm about to move him to the hospital tank too... but I fear it's probably too late.
I did worry about water quality initially. It hasn't been a long time since a major water change, and all the other fish are healthy, but I checked and I found the water hardness is quite high and the nitrates were bordering on too high. I gave the water another change, cleaned the filter and added new nitrate reducing filter pads etc.) I went to the fish shop today to see if I could find something to reduce the hardness (the general hardness is quite high, but the KH is fine) and they told me to try to replace the tank water with rainwater (although I have seen something you can put in the filter to soften the water).
I do have a rainwater tank, but the water is a bit yellowish looking and had some sort of larvae in it (maybe not a problem?!) I tested the tank water and the hardness is extremely low... but am a bit worried about the colour, and whether there may be some contaminants in it (mind you, the dog drinks it and seems perfectly healthy).
However, ultimately I think it's probably not a water quality issue since both gouramis behaved similarly to each other, and the other fish don't appear affected at all. I haven't had a lot of luck with dwarf gouramis, as I lost my beautiful neon blue dwarf gourami earlier this year also mysteriously (as he didn't appear sick at all... and suddenly he was gone). I've had some fungal issues with neon tetras, but most of the other fish seem fine, even ones that would appear to be more delicate (such as glass fish).
I really don't want to give up on dwarf gourami as they're absolutely my favourite fish!! I have read about this Dwarf Gourami Iridivirus (sp??) and am concerned it's that. Perhaps the cobalt actually came to us with the virus and passed it to the flame? (We had the flame a few weeks longer).
Now the fish didn't really look all that sick until displaying symptoms. The flame does appear a bit more swollen than usual, although I couldn't have said the same for the cobalt who looked okay until the last day or so.
I need a bit of advice here! I really don't think Flame is going to make it, which is really sad (yeah, his name is Flame!) especially after the death of the other one a couple of days ago... I am a bit worried about purchasing more, given this history of losing the poor little guys! But I don't want to give up on them either.