new tank-novice-idle fish

Question
URGENT-3 day idle tank(5.5 gallon) before adding 1  black moor and  1
golden fantail (approx. 1 inch each) - extremely lively first few days- looked
very healthy with much activity-now very listless-both staying under cover of
shells in corners-came out for feeding + looked fine then right back to
their
'private' rooms- big no activity change worrying me-what to do if anything?
tank has fake plants,two fan shells and gravel-good filter-no heater or
oxyngenator -told not needed-wife and cat love fish-Ii love wife and cat-
please help

Answer
Hi Scott, :)

I think the issue here is water quality related...Pollution trouble.

You see the aquarium hasn't had a chance to "cycle" yet.

Cycling or Establishing your tank is where two types of special bacteria grow and colonize in your aquarium to get rid of waste the fish produce -- Ammonia.
The first type of bacteria convert ammonia into "nitrite" which is still toxic. But later, the second type of bacteria develop to convert nitrite into harmless "Nitrate".

*You can easily test for all three levels. Ammonia, nitrites, and nitrates with simple test kits from your petstore or they will test your water for free.

They are not present when you first setup your tank and they need time to develop in your aquarium  --- around 6 weeks. And during that time, you must be careful not to stock your aquarium too soon with too many fish or the pollution level will overwhelm what little bacteria that have had a chance to grow and the fish will literally poison themselves. Stocking your aquarium gradually is the key.

After your aquarium is setup and the equipment is running smoothly. Start out with just about 4 reasonably hardy fish like Danios. Ideally you'd test your water for ammonia about every to every other day. Give the aquarium a week and check ammonia and nitrites. IF they are ZERO then you can add about 3-4 more small fish. This process is continued until the aquarium is fully stocked.

~Being that your aquarium already contains fish that can pollute their water to toxic levels in a matter of a couple of days... You'll have to take action on a daily basis to prevent the little fish from suffering from the damaging affects of ammonia.

~The best way to combat this is to start doing daily 50% water changes to lower the ammonia level at least until some bacteria filtration develop. Always making sure replacement water is treated with a water conditioner and you insure the temp of the new water is equal to or just a bit warmer than your aquarium.

Really, to be honest, your goldies need a bigger aquarium. A bigger environment to grow and more water volume to dilute their waste. Otherwise, this may be a reoccurring battle of water quality issues off and on and your goldies may become quite sick. They may be babies now, but of course they will soon grow.

Even an inexpensive 10 gallon with a hang on the back type power filter (10 gallons come in convenient 'kits' nowadays containing everything you need) would be a drastic improvement to the 5gal. Later on they would be better off in a 20-29 gallon tank.

Sorry for the bad news.

I do hope this helps! And I hope your goldies can get better!
Karen~