Ammonia level questions

[MonsterMinis]

A healthy Florida gar will grow approx 1" per month... easily outgrowing a 30 gallon in 2-4 monthes more or less depending on it's current size. GT's and JD's are also Bad tank-mates in general for Gars. everyone as a juvi atm may play nice.. but long-term you will need mutiple tanks to house the fish in all likelyhood. and a Min size of approx 120w gallons for the Gar, or a min of 24" deep tank.

personally I would plan on a tank for the gar and poly, and another for the cichlids. a 75 gallon for each group would likely buy you about 2yrs for the Gar/poly. and I'm not exactly sure on the Cichlids but may be fine for life if they all continued to get along.

 

[Spiritofthesoul]

That takes out all the good bacteria

Doing water change isn't gonna remove any of the nitrifying bacteria. The bulk of your bacteria is found on your filter media, substrate, tank walls and not in the water column. Do the water change! Ammonia, even in small concentration can have unreversible damage on the fish.

I have some algae starting to grow in my tank and i read somewhere that algae will actually eat the ammonia bactera

Algae grow by photosynthesis, they are in no way, carnivores. So bacteria eating algae is just . Algae in the tank help remove nitrates. But many people do not like it since they reduce the visibility of the water and grow all over the walls and deco.
I have algae in my sump, where I don't look until its time to clean the sump so that doesn't bother me.