I just went through 2 weeks of battling hair/thread algae in a customers new set up. The plants hadn't yet had the chance to grow in (only in for a week when the algae started), and after the 3rd week of the tank being set up, it had become a complete nasty swamp in certain areas. I had one piece of driftwood wrapped with Java moss that had become completely covered in this stuff. It looked like greyish-green flowing cotton all over this driftwood. Needless to say, the customer was a bit concerned.
Anyways, I finally got some Flourish Excel in and started dosing at the suggested rate, daily. During that water change I took a pipe cleaner style scrub brush (comes with certain filters) and twisted that in the huge masses of hair algae, and it picked it up very easily. After removing as much as I could with that tool, I then used my hands to gently shake and disturb the remaining moss and other affected plants to remove the last bits of hair algae so I could vacuum it up. I also adjusted the pH controller to keep the CO2 at 30ppm or greater at all times. Previously it was maxing at about 29ppm then dropping to around 24ppm before the controller would turn the CO2 on again. Now it runs from 30-38ppm CO2. The results were immediate. I just went for the 4th week's maintenance, and I barely had to do anything to the tank except just drain and re-fill the water, and of course redose all nutrients. More CO2 in the water makes a HUGE difference. This is the first time I've run a CO2 controller, but it's really nice, and the consistently high CO2 levels really make the difference when battling algae. After a couple of months I'm going to try weening off the Excel, but for now it seems to only be helping to keep excess CO2 in the tank during "grow-in". I believe I will use it in all future new planted setups along with minimum 30ppm CO2 injected to help the plants establish dominance in the tank.
BTW, I also noticed a few stems that had started accumulating some BBA have noticeably started to win over the algae. There are 3 or 4 nodes of new leaves without any BBA on them, this is just 1 week of adjusted CO2 and Excel. Even the BBA that was there seems to be a little more thinned out and more grey colored than black. :dance: