Hmmm.....
You could try to clean them and get rid of it in your 30g before you transfer it.
Every try an algae elimination product before? Algaefix or something like that. There are a couple of people on here who have used products like that with a good amount of success in a reef tank.
Peroxide dips would probably not hurt that bad...
Manual cleaning is probably another option. Since you have a larger tank, a couple of tangs could mop it up relatively easily if there was a problem. Buy a crap ton of snails and throw them in the tank for a couple of weeks - and stop feeding the tank.