SAE's are excellent algae consumers, though really not suitable for tanks smaller than 75 L, and in that size tank they are best kept with species that can tolerate the rambunctiousness noted by others on this page. I have one in a 48 L tank, and he is a holy terror. If SAE's are not suitable or available, try an American Flag Fish (Jordanella floridae) instead, along with some plecos or otos to keep the glass clean. I just put one in a 8 L betta tank in which I had a monstrous hair algae problem, and the tank was sparkling clean in less than a week. AFF's are supposedly even better than SAE at controlling some types of algae. They can be slightly territorial, though mine seems to have reached an equitable arrangement with the betta even in such a tiny volume.
Peaceful, and not just an algae eater, it eats anything and everything. It's doing a great job in the tank. Rarely aggressive, but has some violent moves that can get everything out of its place, although not a big mess anyway. If you were a fish you better not stand in its way, it's gonna knock you out of your place. Not harmful though.
I had read so much about that fish on the Web that I had to get some. I now have 2 in a 200 L community tank along with other algae eaters such as an albino Rainbow shark, Amano shrimps and a couple exotic plecos. And I have 2 more in a 110 L Discus tank again with Amano shrimps and exotic plecos. All are doing well and fast growing. They keep any kind of algae under control and will eat anything else I will feed my fish. I have not noticed any aggression yet and I believe they are a great addition to any planted aquarium.
Definitely a voracious eater. We USED to have a problem with algae in our tank (about 150 L), that all disappeared after we put him in. He does tend to be a bit agressive at times and has 'scraped' our Bala Shark once or twice, removing a few scales, but nothing long lasting or terribly harmful. He's also grown from about 9 cm to 12 cm in 3 months, and seems to eat everything in his path. We plan to put another in the new tank we set up just recently. I would say he's a good community fish.
I kept one SAE for eight years in my aquarium (240 L). It finally reached a size of 14 cm. During his younger days he was a great algae eater, which later changed to a more omnivorous diet including blood worms and artemia. I would recommend this species as a peaceful member of a community tank.
In my experience with SAE's, I would suggest putting them in a plant only tank where you don't have to feed them but once a week. Once mine get a taste for any food that's not algae, they seem to prefer that over algae. Plus, they will destroy Myriophyllum (Frill, Parrot's feather, etc). Otherwise, a very active and good community fish. Algae is under control, but I've wondered if that has more to do with the water parameters, feeding the plants and starving the algae.