Hi my tank is 26g I have 13priscilla Tetras 7amano shrimp 5male platys and 1 silver Molly fluval c3 filter and thinking of adding a second filter. I use fluval Excel flourish for the plants I have an air stone.
An 8 gallon tank is absurdly too small for those fish. First the angel has got to go, they need 29 gallons ideally, I'd say 20 being the absolute minimum. The gourami needs a 10-20 gallon tank. The guppy and the betta are OK for this size tank but out of your fish that is it.