I have 3 three inch fantail goldfish in a 30 gallon tank. Parameters are
Temp 72 F
Ammonia = 0
Nitrate = undetectable
Nitrite = undetectable
PH = 6.8
I don't have an a hardness test.
They get along really well and like to school so don't appear to be stressed. There's managable algae buildup and I change 20% of water everyweek and keep temperature consistant. They're all fed dried flake food once a day and eat it all in 5 minutes. Plant are plastic. Substrate is 5mm gravel. Fish-safe rocks and natural fish safe driftwood for hiding. Minimal vibrations. No direct sunlight. Salt content 5ml per 10 gallons once per week when water changed.
On friday I was suprised to see one of them sleeping upside down at the surface of the tank braced against one of the air hoses. Very clever fish! But no self respecting gold fish would flip himself upside down intentionally. So, I cleaned the tank as usual and treated the water with stress coat to condition it, and fed them some gel food with an anti paracidic in it incase there's something living in him. He hasen't slept upside down since then (friday morning) and otherwise seems fine. But tonight I noticed him sleeping at the bottom of the tank, rightside up, and braced against a broadleaf plant leaf on the lower right corner. He used to sleep with his school mates in a group at the lower right corner. Since the problem isn't showing many symptoms yet, and his mates are not attacking him yet, can you guys give me some advice on what to do? Do you think he might have just unintentionally swallowed too much air? Sorry about the lack of grammer in this post, it's 12:50 AM here and I need sleep. Anyway, I'd like to help the little guy if possible before he can't right himself at all...Thanks everyone! :D