My 90 gal (not planted) has been running for 2 months - a little over 1 month with fish. My lighting is a Marineland double bright LED 1800 lumens.
Have dealt with some diatoms but those are finally under control. (added 4 otto cats a week ago and either they have made endrows or the new tank syndrom is finally passing)

Also, however, I have had a very slow growth of very fine green algae on the top branches (closest to the light source of course) of a large leggy driftwood piece. Now, however, I've noticed there is also a little green algae growth on some of the rocks.

I actually LIKE the looks of it on the branches and the fish occasionally nibble on it. But now that it's starting on the rocks, I'm getting a bit concerned that it might take over.

My question is, am I going to be sorry that I didn't check the growth on these upper limbs?
And if so, what's the best way of nipping it before it gets out of hand - other than leaving the light off?
I leave the light on 10 - 12 hours a day and do not wish to alter that. The tank is in my home office where I spend most of my time and if I can't have the light on when I'm in there working, then there's not much point in having the aquarium.