Hi Christine, I agree with Amanda, you either need a bigger tank or return some of those fish.
I see by your aquarium info that you don't know about the
nitrogen cycle, here's an article explaining it:
http://www.fishlore.com/NitrogenCycle.htm
Here's a basic explanation of the nitrogen cycle:
First your
ammonia (from fish waste and left over food) will rise, in a few weeks you'll see the
nitrite levels rise and the ammonia levels start to drop. After a few more weeks you'll see the
nitrate levels rise and the nitrite levels drop.
Ammonia and nitrites are toxic to your fish. So until your cycle is complete, you need to keep the levels down with daily water changes.
When you having readings of 0 on both ammonia and nitrites with some nitrates showing, your cycle is done.
Do you have a water
test kit? If not, you'll need one. The
API master kit is highly recommended and very accurate. The strips aren't reliable, so don't waste you money on them.
It's always a good idea to quarantine new inhabitants to your tank for a good 2 weeks, some recommend a month to be sure they don't bring in a disease and wipe out your tank.
Good luck.
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