Fee

Hi, I'm new to aquarium keeping and one of my golden danios isn't doing too great.
I've had this tank setup for around 3 months and they've been doing just fine until yesterday. My tank is small, only around 3.2 gallons (US), and I've been doing around 30% water changes every couple of weeks, siphoning the gravel and cleaning all decorations inside the tank. Tankmates include 3 zebra danios and 3 golden danios. Under instruction from my local aquarium workers, I haven't heated my tank, so the temperature is quite cool. I feed my fish flake food for tropical fish, again as suggested by my local aquarium. I use a submerged filter, but I'm not too sure of the fine details about how it works. I haven't tested the water for pH, ammonia, nitrate or nitrite levels as I don't yet have the equipment to do so (but I'm going to get it ASAP!)

My golden danio has been very inactive, sitting at the bottom of the tank in a small corner. He breathes heavily and his dorsal fin seems to be much smaller than it used to be. I'm not sure if he is sick or if another fish has had a go at him and left him that way, and I'm not sure what to do. I haven't put him into a quarantine tank yet as I'm not sure if the stress from changing tanks will just make things worse.

Please help!!
Thanks.

Meenu

Hi, welcome to fishlore.
It is hard to answer your question without knowing your water parameters, The API liquid test kit is recommended. It might be an ammonia issue?

iloveengl

Hello Fee. I'm sorry to welcome you to the forum on such a stressful note.

The water parameters will definitely help give us a better idea about what's going on with the water.

In the meantime, I highly suspect the danios are beginning to suffer stress from the confines of a smaller tank. Danios are very active, fast swimmers; the recommend minimum tank size for them is 10-15 US gallons (more for some varieties). When these fish are stressed, they become very aggressive and nippy. Is there anyway to isolate the one that's injured?

aquarist48

Hello Fee and Welcome to Fish Lore.

Sorry to hear that your fish isn't feeling up to par. Until you are able to acquire a test kit I would recommend increasing your water changes. I think you may be a bit over stocked and the increased water changes will help prevent ammonia poisoning. Too, I would recommend adding a water conditioner, Prime is a good one, with each water change. I have a feeling you need something to detox ammonia in your tank and the Prime will help for short periods. Please note that Prime is not a substitute for water changes but an addition to water changes.
Best of luck and keep us posted.
Ken