There are 9 angel fish in 50 gallon tank. I feed them twice a day and do regular water change of 25 - 30% every week. Every Week when i test the water Nitrates is 5 to 10 PPM. Thinking of doing biweekly water change but am scared if Nitrates spikes.
Have also reduced feeding to control. Please let me know if I can do bi-weekly or continue weekly water change?
Attached the bed of my tank.

Have also reduced feeding to control. Please let me know if I can do bi-weekly or continue weekly water change?
Attached the bed of my tank.
