[usjaz]

Originally posted by rsman
as long as the coil length is chosen correctly (in a correct ratio of diameter to length) its really not, the amount of surface area required is soo small that the pipe holding the bio-balls alone is close to enough

That is assuming that only the coiled tube is doing the nitrification processing (removing O2).

Could it be that the limiting fact here is precisely the assumption that only the coiled tube should perform nitrification?

many ppl ive replied to should increase the flow rate and make no other changes, most dont push there denitrators to anywhere near there limits, then complain that they dont work well enough.

Right. But even with a proper flow rate, The processing ability of the denitrator is still quite limited considering the amount of space it takes IMO. How can we improve it?

im not gona go hunting but if i recall correctly that flow rate is for that media in an open flow, not in a denitrator, with that flow rate you are hoping to process nitrate passively like live rock does, a functioning coil denitrator will remove all of the nitrate that goes into the unit. instead of some of it.

That's a flow thru rate that will cause the media to act as both aerobic on the surface and anaerobic media at the core. see http://www.seachem.com/home/ProductSpotlight3.html

To get complete anaerobic filter in this application a lower rate is needed. I did say that in my post. And if a significant increased denitrification ability can be realized by utilizing these substrate, then one should, and need to, increase the feed rate to supply the sufficient nitrate.

unfortunately when this happens the entire chamber is effected, while some higher density media might still passively remove nitrate the chamber itself wont and you will have nitrate in your water

I guess this is the part I don't understand. I am not sure if I understand why. The flow rate is low enough that water rise up very slowly from the bottom of the chamber , filtering thru a relative denser substrate? (Again, we are not using the bioballs which are much much less dense, thus under a given flow rate, much less likely to host aerobic and anaerobic process at the same time, it will host one or another depends on the flow rate and O2 availibility).

You think there is still not enough contact time w/ these new substrate?


Could the DSB be an counter example in a reversed direction? The top layer is aerobic, and the bottom layer is anaerobic. The rate water penetrate down to the deeper layer of sand is anologous the flow rate of denitrator penetrating up towards the effluent port, in the opposite direction? The obvious key is to use a rate that is slow enough that the aerobic won't overun the aerobic layer? That's not even counting the proneous nature of Denitrate substrate, which should make it more effective aerobically.


And, even *IF* the nitrate is then only removed by the core of Denitrate substrate. *IF* (to be experiemented) denitrifying at a more efficient rate, does it really matter if the chamber is not complete anaerobic? It wouldn't.