Added Fish To Uncycled Tank


I added x2 small goldfish to an uncycled tank. I didn't know about cycling or anything.

Anyhow what do I do now?

Tank is 16 litres, has Aqua one H100 filter and an oxygen shell.

Water is always cloudy? Do I need a small air pump that makes bubbles as well? Fish seem happy they have been in tank for 1 month now and I only added filter 11 days ago?


Grant's Reply

To quickly explain what an un-cycled tank is, it is a tank that hasn't yet built up a big enough colony of useful bacteria in its filter to process waste from the fish into harmless compounds.

An unfiltered aquarium won't go through a cycle. It will build up some useful bacteria, but not enough to have much of an affect on the waste produced by the fish.

This is why frequent partial water changes are essential on unfiltered aquariums.

Depending on temperature, your filter will take up to 14 days to establish a bacteria colony, so you are almost there already.

An Aqua H100 filter has a flow of 100 litres per hour. A 16 litre aquarium needs a flow of 32 litres an hour. You have lots of spare capacity.

I would set the flow control on the top of the filter to minimum otherwise your fish will be fighting against a strong water current all the time.

Give the aquarium another week to settle down and see if the cloudiness clears.
If it is due to a bacterial bloom, it will.
If it is caused by an algal bloom, it won't as the algae are too small for the filter to filter out. Goldfish don't mind slightly green water but it doesn't exactly enhance the look of the aquarium.

Reduce any light sources hitting the aquarium.

You don't need an air pump, and I would be careful that the oxygen shell isn't causing the cloudiness.
Be careful that it doesn't alter the pH too much in a small aquarium as it dissolves.
It adds little if anything to the well-being of the fish.


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