New 450L Cylinder Tank

I've just purchased A 450l cylinder tank and was wondering what tropical fish would suit this type of tank and what type of set up (ornaments) would make the most of the tank?
Any advice you could offer would be greatly appreciated.

Hi Sue

Hardness Level   Soft
Chlorine   0.35
Fluoride   0.94
pH   8.32

Tank dimensions are 30" Diameter by 75" Height

This is my third tank now but a major upgrade from my 100L rectangular aquarium. I spent yesterday setting up the tank with heater, filter, ornaments and plenty of plant but just need to wait for a couple of weeks for the filter to settle and the water to be 100%

Any advice on fish suitable to this environment would be ideal!

Colin is right, there is something odd about your hardness and pH. But how did you get the fluoride reading? If you've taken the data from the water company, the chlorine will be in untreated tapwater not what is in your tank with, hopefully, a dechlorinator.

Once we are sure about the water, you will need to choose fish that are happy in a tank with maximum horizontal swimming distance of 30 inches. Most of the large fish that would be suitable for a rectangular 450 litre tank will be too big for this one. Even fish like zebra danios would be inadvisable as they need at least 3 feet swimming room.


Letting the tank sit is doing nothing, but if you have other tanks you have access to mature media. The easiest way to get this tank ready for fish is to do a fishless cycle, using some media from the other tanks to seed it. Even with a lot of plants you need to check that they will remove any ammonia from the fish by testing the set up with ammonia solution.
However, if by upgrading from the 100 litre tank you mean you intend moving all the fish from that to the new tank, you can just move all the media from the 100 litre into the new tank's filter at the same time as the fish and you won't need to cycle it. Just keep an eye on your ammonia and nitrite levels for several days to be on the safe side.

How are you cycling the filter? Just letting it run is not cycling. You need to add a source of ammonia to cycle cycle a tank. Cycling is the process of growing bacteria in the filter and without a source of food (ammonia) they can't grow.



The dechlorinator will have removed the chlorine that the water company lists.
When you test for pH, leave a glass of water standing for 24 hours and test that as well as newly run tap water. You'll probably find it is different. It's the 'stood' pH you need as the water in the tank has been standing.