Think a search for refugium on the site would bring you more than you could read in a week.

Not really an 'old timer' but I can relate this much, a macro refuge can make a world of difference... I ran some nitrate tests on the water coming in and going out of my refuge (after it was shut down for a couple of days for a repair), NO3 at where water entered the refuge was at 40ppm nitrate and >5 at the output. Now this is with about 4 inches of sand and a combination of chaeto, and various other algaes mixed togother and some LR rubble at roughly 300gph through the 20g fuge. The tank was still pretty young at the time. But today the results are still amazing, we have two refuges attached to the main system, for the added export ability.

On a side note, I no longer have any detectable phosphates or silicates in the water column at all... without running any Phos-ban or similar products.

They also make for a great place to keep injured fish or anything you want to keep, but isolated from the main population. We somewhat regularly grab a ball of macros from the fuge and shake it out into the main tank to increase the pod population for our manderin. And save some out special for the tangs to munch on.

Hope this is of some help.