Nitrate is the by product of having LR.
When your fish emit waste it is in the form of ammonia. The bacteria in your LR convert this to nitrite and then to nitrate, which is a lot less lethal than ammonia in the fish tank and why everyone wants LR.
With that said though very few things remove the actual nitrate itself. Water Changes, Deep Sand bed, Algea (calurpa/Cheato) those can remove the actual nitrate.
The best defense against nitrate is to don't over feed and to have a high quality protein skimmer (Some believe you can overskim, I personally do not) to remove the waste before it has time to start the ammonia/nitrite/nitrate cycle.
Without actually ever having a refugium I would like to know if anyone actually knows what size refugium is needed to effectively remove nitrate?
Example:
10% of tank volume for lightly stocked tank
50% of tank volume for medium stocked tank
100% for heavily stocked tank.
I have looked for similiar information on the web and have been unable to find this information, I suspect that while having a 4 gallon refugium on a 125 gallon tank defenitly doesn't hurt, I wonder what percentage of nitrate is it actually extracting?
Any thoughts?