Brown algae in breeding tank, what to do?

[sevenspeed]

I've got an angelfish tank with a breeding pair and there is some fry in there but I've got a brown algae outbreak. I've left the lights off for like 4 days and that didn't help. There is an Amazon sword plant in there too and its a sand bottom. I'd try to scrape as much as I can but don't want to stress the parents out as they are super defensive.
Any ideas? Does it hurt anything?

 

[indiana.dutton]

A mystery snail or two will do the trick.

 

[kritz]

Also try ramshorn snail.

 

[sevenspeed]

Thanks for the tip, I think I'll stay away from ramshorn though, I had an outbreak of those. I'll just borrow the one from the Oscar tank for now. Meijer is the only place in my town that has them and I got one dead one last time or I'd have two.
Anyway, just didn't know they ate the brown algae too.