You can put more "inches of fish" in a heavily planted tank. Like, if your tank is a 10 gallon, then the "inches of fish" rule says that you could only put 5 zebra danios in it, since they're 2 inches long as adults. But if you have lots of plants, they will absorb some of the ammonia the fish produce, so you'll be able to keep more zebras in your tank than just 5. However I'm not sure just how many more. I haven't seen a rule that says how much fish it's sensible to have in a planted tank.
I found this in a book called Planted Tanks but I dont know if its true.
I found this in a book called Planted Tanks but I dont know if its true.