How to eradricate sea lettuce (ulva)?

[Nway93]

Had some get in on a frag plug and now its popping up in the higher light spots of the tank. I didn't know it was on the plug for a week til it started to grow then immetiatley broke the acro off the plug and glued it to the rocks. The tank is only 20gal otherwise I'd just get some tangs to eat it. Any good ways to get rid of it besides scrub the rock and hope I can keep it in check. Have been on the hunt for a urchin to see if that will eat it as my snails won't touch it. Hoping I don't have to re boot the tank as I have acros beginning to encrust on the rocks and don't want to be set back 9 months...

 

[tehmadreefer]

Bag it up and sell it. Great food for tangs/rabbit fish and macro algae for larger tanks/fuges

 

[Wolf89]

lawnmower blenny