Quote:
Originally Posted by cheeks69  |
Cheeks, thanks for the link, it was really informative. This is a small excerpt from the site that was helpful to me in deciding to remove the bioballs from my system:
5. Remove existing filters designed to facilitate the nitrogen cycle. Such filters do a fine job of processing ammonia to nitrite to nitrate, but do nothing with the nitrate. It is often non-intuitive to many aquarists, but removing such a filter altogether may actually help reduce nitrate. So slowly removing them and allowing more of the nitrogen processing to take place on and in the live rock and sand can be beneficial.
It is not that any less nitrate is produced when such a filter is removed, it is a question of what happens to the nitrate after it is produced.
When it is produced on the surface of media such as bioballs, it mixes into the entire water column, and then has to find its way, by diffusion, to the places where it may be reduced (inside of live rock and sand, for instance).
If it is produced on the surface of live rock or sand, then the local concentration of nitrate is higher there than in the first case above, and it is more likely to diffuse into the rock and sand to be reduced to N2.
Here's another excerpt that I don't fully understand. Would activated carbon filters work to do what this describes?
6. Use a carbon-driven denitrator. There are a variety of different commercial systems available, none of which are especially popular in the United States at this time. However, they can do a good job of removing nitrate and some aquarists quite like them.
In one of these types of systems, a carbon source is added to a portion of tank water in a low oxygen environment. In many cases, the carbon source is methanol. The methanol is mixed with aquarium water in a controlled situation (such as fluid pumped through a coil) and the methanol is consumed by bacteria that use nitrate as an electron acceptor instead of oxygen:
12 NO3- + 10 CH3OH + 12 H+ à 10 CO2 + 6 N2 + 26 H2O
The end result is that nitrate is removed from the aquarium. The typical drawback to such a system is the need for careful control over the conditions, and the consequent complexity that often accompanies such a reactor.