Ok my tanks are full, but is there a list of fish that we really dont need?

I think you need all the fish, because there is loads of different combinations to make different fish. But I'm not sure, so you will also have to wait for other people's views too.
Thanks, Becky.

I say no more of the 4 doller fish

yes I have a step 3 tanks, step 3 food and some good combos but am full and still have 4 magic fish I need, Can I breed the cheaper fish later if I need them?

You can breed most fish later, yes -- and you can always buy more eggs if you need a particular fish but can't seem to breed to get it.

There's many more possible fish combinations than the 60 you can hold in three tanks, so you have to sell fish if you want to try and breed them all (I won't say how many are possible, but I think you can find that out pretty easily ).

The fish may not be worth much but price is not always a factor in what fish to keep. The cheaper fish are needed in order to get some of the other fish.