I had a huge problem in my 2oo gallon tank with 2 sumps... 50 gallons each....one with pumps and skimmer, the other was a refugium with caulerpa..both feather and grape....every month I would harvest half of a 5 gallon bucket out of both the display tank and refugium ....I finally removed my deep sand bed leaving about 1.5 inches...stirred up the remaining sand and did a 100 persent water change....I put filter socks in the sump that is no longer a refugium which I change each week...after 3 months I occasionally pick out a small amount of grape caulerpa....even my back wall which was covered with a slimy hair algae is clean...also my pulsing Xenia which also had over grown the tank has died back to a nice amount...everyone thought I was crazy to go to such an extreme, but for me it has been great....I now have 45 ocellaris ( mocha , black storm, orange strom and several other varieties of orange ocellaris ) 2 large pajama cardinals , 18 rose bubble tip (a couple have split ) blastocysts, Duncan and numerous other frags doing well....I also changed my 6 shop led lights to 4 ocean revive