Have lived by this mostly however in reading and listening to other aquarium people I understand there are other variables to consider. I have a 55 gal tank freshwater. My outside canister filters 415 gal per hour. It’s a medium planted aquarium. I do water changes every 10-14 days and change water while at nitrates are at 25ppm. Here is my question I’ve added up my “inches” and now have 64 inches of fish. I would love to add 8 cherry barbs for their color. Currently I have 7 Rainbow, 3 Cory, 1 bristled nosed pleco, 8 silver tip tetra, 2 long tailed Congo tetre, 2 albino Congo tetra and 4 flying silver fox of which I likely will remove when the get too big. Do you think I should stop or would the cherry barb be safe to add. No current fish problems.