Water changes with playsand are easy. I don't bother with a gravel vac, I just use a hose to syphon straight into a bucket over my outside drain. (The bucket is in case I suck up a fish or snail). I just wave the end of the hose just above the sand, it will suck up all the mess but will hardly...
To get rid of black beard algea on bogwood. I take the wood out and attack it with a wire wheel attachment on my battery drill. Green algea on the glass is normal and I use an algea scrubber to keep that under control.