This is my previous post...

Well I tested my water today and...
Ammonia .25
Nitrites 0
Nitrates 5
What happened? I'm feeding the fish the same amount as always. My last water change was Monday night, but I did a water change last night because I had .25 for ammonia.
Where did I go wrong?
(Sorry for the long post)
~ Jessica

I forgot to mention, I replaced the AquaClear 70 filter with a Whisper 60. I used the same filter media but maybe this is my problem. I replaced the Aqua Clear Wednesday night. My water param problems started Thursday night.

~ Jessica

You haven't gone wrong!

Since you have them in more water, the ammonia is more dilute.
It's good you put the filter media from the 10 gallon in the new tank. It already had a start on getting the biofilter bacteria established. There are probably not enough biobugs there yet for it to be totally cycled (to handle the amount of ammonia being produced and convert it immediately to nitrAte), but you have a good start.

On a side note, you want to keep your filter pads for as long as possible and never rinse them in tap water... only discarded tank water. If they really get stopped up, smack them against something to clear them. If you have two pads, don't replace them both at the same time.

What's the temperature of the tank?
How long had the 10 gallon been up and running?

The tank is about 72 F. The 10 gallon had been running up until Monday so, about 2 full weeks.

~ Jessica

Cool. So the ammonia eaters should be getting up to speed and the nitrIte eaters should be starting to develop.

With pH of 7.4 and temp of 72, I wouldn't worry about ammonia unless it gets up to 2ppm.

When you start seeing nitrIte, I'd add salt at 1 teaspoon per gallon of water. predissolve in tank water and make sure it disperses well when you add it. You can use table salt as long as it doesn't contain yellow prussiate of soda. Rock salt is cheap and works well. NitrIte is toxic. It enters thru the gills and binds up the red blood cells keeping them from being able to carry oxygen. Salt helps protect against nitrIte poisoning because it competes with nitrIte for uptake thru the gills. After you get it salted, when you do partial water changes just add 1 tsp of salt per gallon changed till nitrItes come down to 0, then you can skip adding any more salt. Your partial water changes will then remove it over time.