 Re: Flat denitrator.... Your views
This is really similar to a product made 15 years ago. I can't remember the brand, but do have a visual. It was about a foot long, 2" deep, and 6" tall, and hung on the back of the tank. Water was dripped into it, and the theory was that the first couple of chambers depleted the oxygen, the last few chambers were O2 depleted, or even anerobic, based on water flow. It worked, but needed to be fed. Either a sugar water mix, or Vodka, if I remember correctly.
Frankly, the coil denitrator is an old, but proven (well as proven as you can get in this hobby) design that dates back to Thiel days of the 80's. I don't wind airline tubing, I get a coiled air tool hose from a tool company, like Harbor Freight. It wraps around the outside of a 3"PVC pipe. Water is fed in the top of the coil, exits the bottom, into the PVC though a hose barb, and up through the PVC filled with some type of media, then returned to the top of the overflow, or trickle box for reoxygenation. My coil unit is holding the NItrates steady at 10PPM with 12 total fish, 3 are 4-5" in a FOWLR tank. For the true DIY, and I'm talking CHEAP, go to your local Kinkos and have them save the straps from paper boxes. In no time you'll have all the clear vinyl strips you want that you can stuff in filters, or denitrators.
Good luck. | 
