Imo, h2o2 is a great aid in the battle against most algae. I've got a local trying it on bubble and hair. If it was the eggcrate or not, I'm not sure. My biggest success was adding a huge fuge with grape and feather calupera.
Between dosing the h2o2 and adding the fuge, I won. It also didn't help my sb was a HUGE contribute as it was holding a ton of junk. When I broke the tank down a removed the remaining sand, the water turned almost black. I just don't have luck with a sb where others do. Good luck and hope this helps.