I have live rock in my fuge along with chaeto. I am getting out of this is to take the rock out of my fuge? I thought the more rock you have the better off you are. Now I am confused, lol
That is the idea. The rock is only producing what the chaeto is trying to remove. A bit self defeating. If you are dealing with nitrates, you have more than enough rock, sand, and other substrates in the DT itself. If you are fighting high ammonia levels, then there would be a shortcomings in the system that need immediate intervention and mitigation. However, after the initial cycle, additional substrate is pretty useless, as the bacterial populations are not going to increase, rather vary their metabolic rate to meet the needs of the system. Even tanks with an "average" or "below average" amount of rock in the DT, there is not going to be an advantage to adding more rock in the sump. Rock produces nitrates, it does not provide denitrification. Rock in the sump is nothing more than bio-balls. The adage "the more rock the better" is not really valid. You will be hard pressed to find a system that has a shortage in the nitrate department, that does not have the more serious and lethal issue of high ammonia.
The real problem here is not the shortage of substrates for bacterial colonization. Every surface of the system (including inside pipes, glass, pumps, everything) is a substrate for bacterial population. The problem is the initial start up, and the population was not sufficiently built up (short cutting the process, the mythical 2 week or worse two day cycle, using "cycling aids" that encourage the wrong type of bacterial colonization, the list goes on and on.) The process takes from 4 - 8 weeks, (based on autotrophic bacteria reproductive rates) and it does not matter if the rock, water, or anything else has been in the ocean or another tank. It is a cold start. Period. After the initial break in period, skimming and dentrification/export of nitrate is needed, not more production of nitrate.
The concept of the "refugium" is a very solid methodology. However, a "refugium" used in an export role, is not going to perform well. The chief benefit of the refugium is bio-diversity, and although there is some export (just as there is some export in the DT) the production rates will overshadow the export rates. Hence you end up with a fully loaded in sump refugium and still need an RDSB to get your nitrates down. There are systems that don't need either, such as those running in-tank critter based DSBs, and there are some that just don't have problems, and are "gold."
I have several refugia up and running, they are not in sumps and have common export facilities, associated with DTs.