nitrates and w/c's?

[TrashmanNYC]

I did a 50% w/c this afternoon.......before the w/c the nitrates were around 10-15ppm.........i checked them again tonight and it seems to be about the same.......is this normal, or is there something wrong?

Robb

[DJRansome]

You would expect to reduce Nitrates by 50% if you did a 50% change. What does your tap water test?

[Afreakin]

Are your filters clean? Do you clean your substrate? At times your filter can house a large amount of Nitrate. The same thing goes for your substate only here it will most likely turn to ammonia in the form of gas pockets, if it is not tended to on a semi-routine basis. How long after you did the water change did you test for nitrates again?

Definately check how old your test kit is and check the nitrates out of your tap water.

[TrashmanNYC]

i changed out the floss on the HOB a few days ago and the canisters have only been running for about 2 weeks............
i also vacuumed the top of the sand and "raked" it with my fingers..........
i tested it again about 6 hours later........
im gonna test my tap water in a little while........