My driftwood has always supported a large population of Cladophora. It had vanished while the log was dry, and didn't show up in the new aquarium until I replaced the lighting. I'm not sure whether this reflects a lag time in growth (from spores or resistant bits) or whether it was simply a response to the higher light. (Obviously the high light helped it grow, and grow it did, like crazy). While many aquarists consider Cladophora to be the bane of their existence, I'm actually fond of it, as long as it stays on that piece of wood. It does require regular removal, but given its coarse texture, it is actually quite easy to remove.
If Cladophora had been the only issue, I wouldn't have been bothered. I also managed to attract a population of what some call 'green dust algae' - fine stuff that covered the glass. Initially I took it for green water (which is a problem) but then I realised it was just on the glass. It's easy to scrape, but right now it's growing like crazy. My problem is that I also have at least two other types of algae, and these are a bit problematic. I have some blue-green algae forming in a couple places. I don't care about it on rocks, but it is also growing on my plants. That's a problem, that I will need to sort out one way or another (it's not an easy problem to solve). Then I have something that's new to me. It fits the description of 'green hair algae' (and possibly some 'thread algae' on my filter outflow). Not good stuff to have around. For starters, it seems to grow like crazy and attach to anything (plants, heater; it's even smothering the Cladophora). It's also very slimy and insubstantial - people recommend twisting it around a toothbrush to remove it).