Trouble247;1221822; said:It's called a 'denitrator', yourokit. You can buy them for $$$ or there are a few DIY plans out there in Interwebcyberspace, the tube has to be several times longer than Merbeast mentions I believe. They work by slowly flowing a portion of your tank water through the long tube coil until anaerobic bacteria colonies in the last 1/3 of the tube consume nitrates before the water is returned to the tank. The flow has to be drip-drip slow.
The dangers I have read, are not limited to, but include that they introduce toxic gases to your tank. I also believe they strip dissolved oxygen at the same time, hence why I won't use 'em.
If you would go through the trouble of setting one of these up, why not just DIY a constant flow water-change system?
Oh, and on-topic, I agree with Merbeast, increasing the surface area available for nitrifying bacteria could [if there was sufficient bioload to feed them] increase the size of the colony resulting in faster creation of Nitrates, necessitating MORE frequent water changes...
Due to restrictions imposed by apartment-mates, I cannot set up a diy water-change system.
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But one would rather have nitrates in the tank than nitrites so increasing the surface area for nitrate creating bacteria is a good thing? More water-changes doesn't seem to be the likely outcome, but I'm not sure.
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And as you mentioned, only so much bacteria can grow; only the amount that can be sustained by the amount of ammonia produced.