how many fish to cycle a tank?

[Kirsty]

I read that too few means the tank wont go through a full cycle and too many means the fish will die.
How many would you recommend? I have a 63 litre tank.

 

[pseud]

4 or 5 hardy fish, such as zebra danios.

 

[foty89]

It is not really that the tank will not cycle, it is just that it will be in stages. When you do a fish cycle, the beneficial bacteria need to develop in the tank while there are fish there. This bacteria takes time to grow and you have to balance it's growth with the number of fish. Too many and the fish will die. However, too few DOES NOT mean that the tank will not cycle. It will cycle to the level of fish in the tank.

So each time you add new fish to a tank cycled in this way, it will go through a mini cycle where the bacteria have to grow in amount to handle the new fish.

This is why the fishless cycle and products like bio-spira have gained popularity. They are arguably simpler and you can stock at higher levels faster.

I would say that the suggestion of four or five zebra danios is a good one, they are a hardy fish and are often used in fish cycling a tank.

The sticky threads on this board and others are great resources for learning about keeping fish, make sure you use them.

 

[Shnookina]

i have a 28 gallon tank and these are the fish i have in my siggy they have been cycling for about a week now and only one has died, and that was with dropsy

 

[b.c.f.c]

i used 4 zebera danios to cycle my tank and now still have 1 of them left

 

[foty89]

i have a 28 gallon tank and these are the fish i have in my siggy they have been cycling for about a week now and only one has died, and that was with dropsy

I am somewhat surprised that your neons are doing OK, they are not generally a good fish for cycling. However, you do have a decent size tank with only a few fish, so maybe it is going to work out for you.