I have high nitrates in my tank... I am almost ready to change the filter in my Tetra Whisper filter. Will that reduce my Nitrates? If not what is the best way to reduce it? The rest of my water perameters are good. Thanks for the help

water change is the best way to reduce nitrates
in your tank. unless you are practicing hydroponics
in your system, there is no other way. please take note
that you have to take precaution in cleaning the filter elements.
there are some very informative thread here about filter cleaning.

as Paul pointed out the only way to reduce nitrates is water changing. the amount you change depend on your tank size and amount & size of your fish. if you are over stocked you could be doing 2 water changes a wk of 30%. if you need to do more than this removing some of the fish is the only answer. you should aim to change 30% of your water in 7 days or a little longer, this I consider reasonable for a oscar tank. your readings should be below 40pph. Its worth checking your tap water too as this may be high in nitrates and can prsent problems.what is your tank size and how many fish do you have, size too??

Thanks for the info... I have a 50 GAL tankwith a Bumblebee Ciclid about 6", an Oscar about 2 or 3 " a pleco and 2 small Cobalt Blur ciclids about 1". I dont think I am over stocked.

50 gal size, with those stock.... you are in the
critical limit. for the meantime, you can bear with
it but requires frequent water change. but oscars grows
fast and in a few months.... problem will crop one after
another.

you soon will be overstocked. 50g is a good size for one oscar no tank mates. so six months and your problem will be arise. look at your feeding and cut down, over feeding will result in high nitrates as fish will eat more than needed. also check your tap nitrates as said, some members have had very high tap nitrates and I myself lived in a area that was 20pph straight from tap. if you tap water is ok you need to do more or larger water changes. I would go with more as there is less chance for anything to go wrong.