I've got this algae that looks like BBA that has been growing on my canister outtake and on the upper leaves of C helferi for a while, but is now spreading to C parva on the ground. I turned the lights back on in the evening a few too many times and did a big trim a while back that may have caused this spread. My dosing routine is kind of sporadic as well. The only thing that makes me think it isn't BBA is that it grows well on surfaces with high current and I thought BBA didn't like currrent.
Help me kill this stuff! I'm cutting my lighting levels in half (96W to 48W) and I've squirted some Excel on a parva leaf to see if it responds. Any other advice is appreciated.
Thanks,
Doug
That is BBA. It was BGA that some thought was affected by water flow (not true). When you have BBA it usually means that your CO2 levels are too low, or that you dose Excel sporadically (pun intended).
Thanks Cristy! I did recently shift the location of my CO2 diffuser (a modified Duetto Mini filter boosted with a Koralia nano) towards the back of the tank, which did impact the CO2 dispersion. A CO2 mist used to flow over the parva. I just moved it back to the front of the tank.
I'm also curious whether a UV sterilizer would prevent this type of algae from spreading.
Do the spot treatment of excel make sure you turn off all filter and let it sit for a while. I don't think uv will work as only free flooting algae kills it.
The only thing that makes me think it isn't BBA is that it grows well on surfaces with high current and I thought BBA didn't like currrent. 
