How many goldfish can I keep in a 30l tank?

one - cos they grow big so it will outgrow it. It is the surface area that is important too, not the litres. You can put more fish in a long tank than a tall one for this reason.

um the tank is 50cm X 25cm X 25cm and I have three in it?! Oops

It kinda depends on how big your goldfish are?

If they were like 1-2 inches then i would have thought that would be ok, but if they where like 10 inches i would have definate concerns :lol: :lol:

You just have to realise that they won't stay there forever, they will need to be rehoused before they get to big

nope they are wee small frys 1-2 inches

The final size tank they need will depend on the type of goldfish. The single tail varieties (common goldfish and comet) grow bigger and need more swimming space than the fantails, etc.

My daughter's 2 fish (a fantail and a black moor) are in a 100 litre tank (76x30x50) and this should be big enough for them to live their lives out.

Single tail varieties make great pond fish.

MCT

all were really saying is that once they get bigger it is a good and valid excuse for you to buy a new larger tank. :lol: :lol:

They are fine at the moment debs but will need room to grow. They will be fine for a year or two yet

Personally I do not like to see comets in aquariums, they should be out in nice big ponds. The fancy goldfishes with the long tails are different as they do not swim far or fast.

As a rough guide, to work out how many coldwater fish you can keep, multiply the length and breadth and divide the result by 76 to give you the total amount of fish you can keep in cms. So, 50 x 25 divided by 76 = 16.4cm total. So, theoretically, this means 1 fish 16.4cm or 2 fish 8.2cm or 3 fish 5.4cm etc.

This is a rough guide only as the bigger the fish, the more waste it produces. 3 small 3cm fish will not produce anywhere near the same amount of waste as one 9cm fish. Especially goldfish as they are a full bodied fish and poo heaps!

Good filtration and/or regular water changes are a must for goldfish to be well cared for. Avoid undergravel filters with goldfish as they dig through the substrate and have a tendency to expose the filter plates with their digging.