Hi, I have a 3 week old 55 gal tank (I'm into my 4th week now) with 2 angels, 4 zebra dano's, 2 platy, 2 swordtail and 2 cory cats. I've kept my temp at 80 degrees, my pH 8. I figured my tank was starting to cycle because I started to see an ammonia reading. I started to do 25% water changes...