They sell acylic magnet scrubbers, but first you should get to the bottom of why you are having the algae problem to start with.
1) How old is your tank
2) what do you have in the tank..fishes, inverts, etc.
3) Your water quality readings please
4) Using RO/DI water?
5) checked for PO4 lately>
6) feeding and light use x % hours on...
lets get those first.....
