yet another algea question

I've read all the post on algea and liked all the answers but what do you use when youve got puffers in the tank..thats a mighty expensive snack food for them..

I've got a kent metal scrapper also in the tank is a chocolate starfish and a pencil seaurchin but they just dont seem to do the job...I could scrape which i do but I was hoping that someone out there might know of something else living that a puffer didnt like to eat that would clean.. cause its much better the have live things than mechanical things in my opinion but thanks atleast for your reply