If you want a nano reef like I did, you dont want to spend hundreds of dollars on a skimmer thats gonna pull out every nutrient good or bad from your tank.

The CPR backpacks, and Knop skimmers are highly recommended. I was on a budget, and the CPR backpack was both a bit out of my budget and not available locally here.

I choose to go with the Red Sea Prism. Its relatively cheap, does a relatively good job compared to the seaclones, and skilters, and its HOB, so it stays out of your tank. I love mine, it pulls out a bunch of brown gunk. The only draw back are its a fairly noisey (All that air injected), and the surface skimmer attachment is a rip off.

Why do you need a surface skimmer? Many small tanks do not have overflows that can skim the top of the water. By adding a surface skimmer the protein skimmer will be able to suck up that nasty film coated with protein on the surface of your tank, and oxygen exchange will also be helped. This mod should work for other skimmers, or powerheads, although some mods may be needed. I am not responsible for any damage, or injury incured. This is only a suggested guide.

This is what I used, 1 Black PVC 1 1/2" extender from Home Depot. These slide inside a normal black 1 1/2" PVC pipe, and one end is tapered. I also had a left over piece of acrylic which I cut to cover the non tapered end. I also used my trusty dremel roto tool.

Assembly:

1. Start by cutting the PVC to the length you want, I would leave about 1/2" at the bottom between the PVC and the bottom of the Prism strainer.

2. Than cut slots out with your dremel at the tapered end. I went down to where the taper starts, and it seems to be a good length. (note, if you want extra strength, leave PVC at the top, IE dont cut all the way to the top and leave the ridges connected.) Also dont worry that in my diagram the slots end sort of on a slant. That was just my lazy photoshoping skills. Much too tired and busy for that. Maybe I'll edit the photo later.

3. I used aquarium sealant to glue the acrylic cap on to the other end.

4. Let dry, slide over prism intake. This size of PVC was perfect, I figured out while I was testing it that I didnt need to glue on suction cups, because it was a perfect fit. Not too tight that it would scratch the prism, but snug so it would stay on by itself.

The water flows in from the top of the tank, down the PVC tube and into the skimmer ensuring the water with the most protein actually goes through your skimmer.

Hints: Make sure your PVC tube is long enough so that you can adjust the height of the surface skimmer up and down and not have the strainer on the intake of the prism hit the bottom of your surface skimmer. Also make sure the groves you cut out on your surface skimmer are long enough so you can set it for varied flow.