I keep a large 210 gal
. reef tank and as a sump/refugium i have 3 chambers. Chamber one contains filter floss and that is it. I change often to avoid bad bacteria growth. I also clean it often with watering hose which has high pressure to get out all of the dirt. Then I have a few sections of walls to prevent micro bubbles from passing to the next chamber. The second chamber is the biggest. It is kind of the refugium section of it. I have a six inch sand bed with a little bit of live rock, and about 10 3 inch tall and 4 inch diameter pvc
pipes which as a great place for good bacteria to grow and copepods to take shelter in. Then I have some high quality cheato algae connected to the rock. Then I have another section of micro bubble walls. In the final I have two odeysea return pumps which have pre-filters in them. The filters have a lot of refugium rubble on-top of them. The sump/refugium has hoods on it and a zoo-med flora-sun light on top of that. It provides the perfect light for the cheato algae.
As for the uv
sterilizer, I am all for them but I am more for multi-functional filters. I use a Vortex D-1 diatom filter. This filter forces micro particles through dead diatom skeletons. These skeletons are 0.5 microns to 1 millionth of a micron. (Of course the 0.5 micron is more common in the powder than the 1 millionth) It takes in diatom algae, parasites (yes including the parasites that cause ick) poop, and just about anything. It also polishes the water and makes it absolutely crystal clear!
In conclusion, my opinion does not mater. I am just saying what i do. My motto is, "If it works for you do it, if it doesn't then don't!" Try different ideas but when you find something that works, no matter how many people tell you it is the wrong way, don't listen! "If it works for you keep doing it!"