Snake_Eyes;1262711; said:If you don't have a test kit get one. You'll have to determine yourself what amount of water needs to be changed to keep your nitrates low.
I'm currently treating HITH with my oscar and I'm doing three 50% or two 75-80% a week.
I would also see what you water is comming out at from you tap, I had a prob with nitrates, they was reading on the test kit I had dark red [dark red = 50 - 75] BUT when I did a tap checked on the water from the tap that was reading 50 - 75 straight away, I did try other kits but all gave the same.
Good luck getting him sorted out
Shane