Water changes if balances are correct

[bobby]

I've been changing 25% water weekly, i check the water before changing and the nitrates and nitrites along with gh ph are all ok. do I need to do a water change as often?

Bob

 

[tstenback]

I would perhaps cut back on the amount say 10% weekly unless the nitrate level is higher than it was the previous week before the water change. The nitrate level is usually your first indication that something is going on in the tank. If you measure this week and the level is 20 ppm and next week the level is still around 20ppm then i would just do the 10% change. If the level is up to around 40 ppm then i would do a larger water change. It could mean that the fish are creating more waste and it may be time to move some out to a new tank or that you are overfeeding or there is something in the tank causing a problem like an old piece of tubifex that you didnt see. HTH