Here is my experience. I have a 120 gallon and 56 gallon display tank going to one sump. I had Marco rock in the one tank for years before plumbing them together. I had GHA I would manually remove. It would be back the next day. I have a 15"×15"×8" area I put cheato in with a h380. I had the cheato die 3 times. My sump would get over run with GHA. I banded my head against the wall several time. I tried several different things but finally I was able to get rid of most of the gha. I had to shorten the photo period of the cheato until it started to grow. The increases it an hour a week. I would get gha growing on the cheato. I just kept removing it. Finally the cheato started growing. Now I have to keep it trimmed back to stay in its area. I have turned off all my other filtration including protein skimmer. Water comes out of tank runs through cheato and gets pumped back into tank. I have auto feeders that pump pellets 5 times a day. I also make a homemade frozen food. I have been throwing in a few cubes of that along with spot feeding reef roids and a few other things. I have to keep a close eye on.my phosphate. If not it will drop to 0. I use the Hanna phosphorus checker. I try to maintain 20ppb. I am getting ready to add some more fish to help maintain the levels.
as a person that struggled with gha for 2 years before adding a refugium and managing to beat it I would recommend you just do your best to ignore your frustration about how things have been and just focus on where you want them to be. what I mean by this is, you have initiated a new intervention to beat the gha and it isn't a good strategy to not give the system time to sort things out before you start piling on more nutrient reduction methods. just be patient and let the chaeto sort the gha out for you and if 2 months passes with little to no progress then implement a change.
