The instructions say to rinse the loose carbon dust, but the water doesn't have to wash clear. I've done this and when I put into my filter along with a bio-bag, black immediately entered the water. I took out asap, let it clear up, changed water, next day Nh3 & Nh4 where high again. I put in again today and left for awhile with the tank water turning black, then clearing. Is Ammo-Carb suppose to do this? This is only a 16 gallon tank and I have too many fish based on 1 gallon per inch by 2 gallons. I will be purchasing a larger tank, but what do I do meanwhile? I test the levels of this and the PH daily as the PH has dropped to 6.0, despite using API PH Up for several days. Our tap water has a high alkaline level of 8.2 to 8.6. Can you help me to figure out and fix what is wrong? I've tried everything I know except suck the gravel clean with a siphon. I don't understand why the Ph has dropped so low when I was having trouble with it being too high originally.