Biohome Ultimate - Nitrate Removing Filter Media

I've got Seachem De-nitrate media in several of my filters.

Hi Littlefish,

Please tell me more about the Seachem De-Nitrate. I know of this product but I've never used it. Was it effective?

JPC

Quote from: Hampalong on February 13, 2019, 05:18:00 PM

The bacteria involved are Nitrobacter.

It seems strange that Nitrobacter can also work as denitrifying bacteria. Nitrobacter is a nitrifying bacteria and, until Dr Tim Hovanec came along, Nitrobacter was considered to be the bacteria responsible for converting nitrite to nitrate. Perhaps I've misunderstood you. Quite possible - it's been a long day!

JPC

Nitrobacter are still one of the bacteria involved with nitrite->nitrate conversion, but only in an aerobic environment. In an anaerobic environment they’re able to get their oxygen from nitrate and nitrite.

Nitrobacter and Nitrospira are involved in cycling, as well as probably others that haven’t been catalogued yet. In a mature filter most nitrification, in most cases studied, is actually not done by bacteria at all but Archaea, a much under-studied kingdom similar but distinct from bacteria. Nitrobacter, Nitrospira and Nitrosomonas are still always present (in the limited studies done so far), usually in the minority, but sometimes in the majority. Much more work to be done there though, and our “knowledge” of all this is still in its infancy.

Let me start by saying I’m no chemist.

NO3->NO2->N

It doesn’t produce ammonia but it does produce nitrite. To have significant denitrification in practice you need a lot of porous media, and ideally a slow flow so they take the oxygen off the nitrite aswell (NO2->N).

When Siporax was released on the market there was a booklet available with info about the product, it’s concept and manufacture etc, which also detailed (with pictures) a test setup of their own. The tank was about 2’ x18” x18”, lightly stocked and moderately planted, and the denitrifying filter, which came after an ordinary nitrifying canister, was essentially a large biorb. This was required to give zero nitrates.
I tried a homemade one once with a tapped off trickle from a canister into a 2gallon bucket with about 4-5” of siporax (The outlet was just above the siporax so that the water ‘lingered’). I couldn’t make the incoming flow constant with that method and the tank was reading 1ppm of nitrite (big tank with adolescent Oscars).

A friend of mine set up a slow sand filter in his tank for nitrate removal. 
Don’t know how they work but it was quite effective. Took an extremely long time to get the flow rate through the media correct (if the flow was too slow it caused hydrogen sulphide to be produced).

Slow sand filters are definately effective, and in some places are still used for drinking water treatment. I didn't know about the hydrogen sulphide though!!!