Advice about sumps

[StirCrazy]

Originally Posted by Delphinus

I always thought it was just a case of the bioballs were an aerobic zone and you need an anaerobic zone for nitrate reduction.

there are actualy 3 different zones, if our tanks only had anarobic, and aerobic zones we would all be cool. the backteria that is responcable for nitrate break down lived primaraly in the anaerobic zone but is quite capable of functioning in the aerobic zone but art a reduced rate. aerobic being lots of air, anaerobic being low air.

the problem comes in when you have an anoxic (*SP) zone, it is where there is no air period and a different bacteria lives here that can take the nitrogen gas which is traped in pockets in the sand bed (which is harmless) and break it down further in to a sulfer gas byproduct which is the black pockets you see in deep sand beds that have been knowen to harm the tank when disturbed.

Bio balls only create an aerobic area, so they will do there jobe and turn amonit into nitrite then nitrate, but if that is all you have ie, no live rock, then it is going to be at a reduced capacity to turn that nitrate into nitrogen gas, which will make the nitrates go up.

Steve