I've only had one-spots, not the larger foxfaces. The one-spot does eat a variety of algae, but with any critter (fish, snail, nudi, slugs, crab, etc.) they will all have preferences on what they like to eat. So, there is never any guarantee that they will eat the algae you want eradicated. But, the one-spot, like the larger foxfaces, is an herbivore, so you have a good bet it will help you with your algae issue. One suggestion, limit the food you give it so that it will be forced to eat algae. Monitor how skinny it gets, how much algae it is eating, and if it isn't getting enough food from the algae, then make sure you feed it. Don't let it starve, but encourage it to eat the algae in the tank by not feeding it too much.
- Admiring Di's lovely new addition - the crispatas....