Just wondering why this algae isn't growing in the sump but is growing in the display so badly
Shouldn't grow anywhere if you ask me. What are your phosphate levels at? Should be at zero!! Yours aren't if your having hair algae.
Get some phoszorb from seachem and it should start to clear in about 2-3 weeks. I'm just surprised the ho2o didn't help? Did you include your sump to the amount of water you have (with your DT) ???