I did the fishless cycle until it was ready. I first introduced 3 Platty. All levels stayed at 0. After a week I introduced 3 more Platty. All levels remained at zero at first. I took 1 Platty back to the store as he had become aggressive. The ammonia had gone up and that is why I believe it happened. Anyway, I also found out that 6 Platty in a 10g were too many. Is 5 still too many?
Tank Size: 10g
Fish: 5 Platty
Tester: API Master Test Kit
Filter: Aqueon Quiet Flow 10 (It was a smaller filter before, but I changed it to this and seeded it.)
Temp: 74-76 Light off, 76-78 Light on
Heater: I don't use a heater.
I use gravel.
Food: Freeze dried brine shrimp, tropical flakes, freeze dried bloodworms. I feed them once a day.
Do I need a bigger filter? What kind of filter should I get for my fish?
Edit: I do 20% water changes every week. Last week I did a 50%.