Ammonia levels will not drop

Question
I have a 25 gallon tank that's been set up for about 6 weeks now. After the tank cycled I went ahead and added a few fish. As of now, I've got one Pleco, one Dalmation Molly, 3 Striped Danios, and a Platy.

I have a heater in there that keeps the temps between 76-78 degrees at all times. I've also got an air pump pushing air through an air stone and through a little ship/hiding hole. Not sure how much of this matters, but I'm trying to be as thorough as possible.

For the last two weeks or so, I've been seeing ammonia levels rising with my tester. I'm up to about 1.5ppm now. Everything else tests correctly, except nitrites, which shows barely over safe levels. pH shows between 7.2 and 7.8 at all times as well. I've been doing daily 20% water changes, and vacuuming the gravel every other day to try to bring the ammonia levels down. I've been using an ammonia reducer (AmQuel), and I've gotten to the point now where I'm only feeding them tropical flakes once a day.

I use aquarium salt to help with water chemistry, and every other aspect of my water seems to be perfect or near perfect.  I've since gone from a cheap filter to an aqua-clear 30 gallon, as well as using ammonia reducer media in the filter.  

I've followed every instruction I could find about reducing ammonia and it still seems to be slowly rising.  The fish seem fine.  They are active, seem to be breathing normally, and there is no redness or bleeding from the gills.  They eat like crazy, swim around with eachother, and overall, they seem happy.

One more note, I've tried two different ammonia tests.  The one I use daily is an API ammonia tester, and the second is a cheap dip strip test from wal mart.  Both show about the same levels.

Thank you for any help you can give.  Sorry for the long question, I was just trying to be as thorough as possible.  

Answer
Hi Chris;

The nitrogen cycle is commonly misunderstood so it's important for me to know how you got your tank through it. Were there ammonia or nitrite readings during that time? It usually does take a few weeks. But in order to get a new tank established and through that break-in period it needs fish or some other source of ammonia in it to add waste for the beneficial bacteria to feed on. Once the first fish (or waste product) is added then the process begins. If the tank was empty of fish or another source of ammonia during the time it was supposed to be going through the break-in, it hasn't done that yet. I think the addition of fish has now started the process and it's going to be a few more weeks before it finally settles down. But, even if the process was completed, the addition of fish will cause ammonia to rise because the beneficial bacteria needs to now grow new colonies to compensate for the new additional bio-load. It can take awhile for it to settle down again. That's why it's important to add new fish in very small populations. The beneficial bacteria can compensate for the new ones more easily and ammonia levels won't rise so high so it causes less stress to the fish.  

Here is my own web page about the whole crazy process and how to handle it;

http://expert-fish-help.xanga.com/

Sometimes the addition of products that are supposed to bind the ammonia such as "AmQuel" or "Ammo Lock" can cause a false positive on your testers. Look on the label of the tester and see if it uses "Nessler Reagent". If so, you may have to get a different type.

Get back to me as soon as you can about the break-in method you used and hopefully we can get this straightened out soon...

At Your Service;
Chris Robbins