I have a 20 gallon tank. 9 days ago, I added Ace Hardware brand ammonia to the tank and got the ammonia up to 4ppm (I have the API test kit). I keep the light off and the temp of the water is about 78 degrees fahrenheit (fixed-temp, submersible heater). I have checked it a few times between then and now and it has remained at about 4ppm. Today, it finally appears to be somewhere in between 2ppm and 4ppm. Is this the typical amount of time it takes to get things going or is there something I can do or test for to speed things up a bit? Thanks in advance!!