Personally I don't know if refugiums do much of a difference with the types of problematic algaes, though my little 18 gallon has a refugium and has never had a problem with bubble algae.
I do know if you break open those little balls, they will release spores that grow into hair algae. Emerald crabs are known to eat the bubble algae.
How big is your tank? Do you have a protein skimmer in use?
Please note...reducing elements that contribute to algae growth will prevent algae from growing, but not get rid of what's already there.
I'm not sure if I agree with your theology here. A refugium harvesting macroalgae should definitely help eliminate existing nuisance algae and prevent any more from growing.
Both micro (nuisance) and macro algaes are fueled by two sources...light (photosynthesis) and nutrients (in most aquariums, phosphate and nitrate but could be ammonia or nitrite). Excess of these nutrients can fuel unwanted algae growth (diatom, hair, bubble).
In order for the algae to be eliminated, it must be starved. In order to starve it, its food sources must be taken away. So essentially, you could starve it from light (not practical in a reef environment) or starve it from phosphate and nitrogen(more practical and beneficial to reef organisms). Many people now days rely on a refugium harvesting macro algaes to do the job.
Macro algaes (caulerpa, chaetomorpha, gracillaria, etc) will "out compete" micro algaes for the same food (phosphate, nitrogen). So in a system implementing a properly functioning refugium, problematic algaes in the main display should be starved and eliminated.
A few years back my 180 gallon had a problem with bubble and hair algae and cyanobacteria. A few weeks after I hooked up a macro algae refugium, the nitrates and phosphates became undetectable and all of the nuisance algae soon disappeared.
Seafan, this doesn't seem to help in your situation because you mentioned you have caulerpa growing in your tank. This could definitely prove to be a more difficult situation to fix. Caulerpa is a macro algae so setting up a refugium,
IMO, isn't going to erradicate it. The refugium may slow its growth because other algaes will be competing for the same food source. Caulerpa can grow at an amazing rate and sometimes spread through the main display like a weed. Manual removal and possibly the addition of a tang may do the trick.
IME, turbo snails can do a job on caulerpa, so you could consider adding a few to your tank.
HTH and Good Luck!
