[Myka]

Looks good, great job on the rockscape...narrow tanks can be a real bugger!

As far as the filter sock goes, there shouldn't be anything in it - assuming it is a 100 or 200 micron felt filter sock? The filter sock is meant to filter out fine particles, and should be changed everyday or every second day. They can be washed inside out in a washing machine with just hot water (no soap!). Carbon (or purigen or GFO) would go into a filter bag which is just intended to hold the media and will be quite a bit smaller. Filter bags of carbon (or whatever) do well if put between the baffles where there is high flow. Most people change these medias every 4-6 weeks and just rinse the filter bag before refilling. Since the filter sock needs to be changed so often (or it will clog up, overflow, and also cause nitrate) and the media in filter bags is not changed so often the two don't go together very well. Also, carbon in particular needs to be packed in fairly tight as carbon tumbling in the water will rub against itself and make carbon dust in the tank which is not a good thing.

Personally, I don't like "refugiums". I prefer a "macroalgae chamber". When people setup a refugium they usually want to do one or two of two things: grow pods, reduce nutrients. I find with a macroalgae chamber you can do both very well IF you set it up well. Get a ball of chaeto, put it in the chamber, make sure it rolls freely in the water (may need to add a powerhead, will need to trim it often), add a 3500-6500K spotlight. Pods will live in the chaeto, and the chaeto does a great job of exporting both nitrate and phosphate, plus it is simple, easy, and cheap to do. The trick is to keep the chaeto tumbling freely. Shake the chaeto once a day or whenever you want pods to fall off and go up to the tank.