Nitrates help

[Myanth]

I'd be concerned with the fluval first. Any time that I have introduced filter media it becomes a magnet for nitrates as caught organics deteriorate. I believe in high water flow, 1lb/gal of rock and .5lb/gal of sand. Keep as much sand surface uncovered as possible to prevent dead spots in the sand and only media filter once every couple of months with an agitation of the sandbed (I use a powerhead to stir things up)