Do you need to cycle fish tanks?

Yes you need to cycle your tanks. Cycling is basically the start of the bacterial formation in your tank. What this bacteria does is remove any ammonia in your tank. Ammonia is poisonous to fish. You can cycle your tank with fish or without. Going a fishless cycle is better and easier. If you will cycle with fish get a few cheap fish don't buy expensive ones. You can find a bunch of articles by just searching google.