DIY Nitrate Filter Idea
 

On both my 46 and 15 gallon tanks, I have an HOB filter. Since I am experiencing problems with nitrate in the 46 gallon, I was thinking of putting bamboo in the HOB filter. What I wuld do is put the roots in the place with water and keep the leaves above the water. Would this be helpful in the removal of nitrate? I'm sure it would look cool.

I haven't ever heard of bamboo, nonetheless fake bamboo, reducing nitrates. You may want to try to eldodea/anacharis, or duckweed, as I have heard they consme 'trates. Just add a little wall of like eggcrate so it stays in the HOB.

I remember someone briefly mentioned the idea on another forum.

At best they'll help a little. The downside to doing something like this is that to control nitrates naturally requires a tank over-run with plants and only a few fish. A few plants will consume some nitrates, but you're not going to control your nitrates with them.

what about a sump with a Refugium ? and heavly plant the refugium?

Like I said, tons of plants, few fish.

If you've got nitrate problems the best way to handle them is water changes.

I agree. I've got quite a few plants (tank is stocked to its limit fish-wise) and I'd have to miss 2 to 3 water changes before I'd ever get a large nitrate reading. My vote is always for LOTS of plants. :-D