Refugium are a very good idea. I have never had algea or nitrates and I've been able to keep lots of rare fish because of all the micro organisms.
P.s my refugium is 15 gallons with cheato on top, live rock in the middle and sand on the bottom
see i have a refugium currently but am looking to do a new sump a bigger one, ive seen a lot of tanks with just another fish tank with no baffles. take Julian Sprungs sump for example amazing tank barely anythin in the bottom tank.
Refugiums main purpose is providing a safe place predator free, where your pods can populate. A ball of cheato isn't going to remove that much stuff from water. But it will provide a nice home for pods.
When I ran my biocube with a fuge i constantly saw pods. Now that I don't run one I do not see pods.
No refugium for me. I use all the basics, skimmer, gfo and gac when needed, and weekly water changes. I also dose red seas nopox 3x per week. When I tried a fuge my main drawback was a lot of coralline growth all over my sump.
I do not use a refugium and have no issues with nutrient control (0 phosphates, 0 nitratres, etc.) My reef is maintained by aggressive water changes, skimming, and GFO.