I know that Silver Dollars eat plants, so I wouldn't be surprised if they were living off algae...to a certain extent. However, I'm sure they're also eating the flaked foods...snatching it when it sinks, or foraging it off the gravel.
If they're growing, their eating.

Have fun!

-PF

If you do an internet search on "Silver Dollar fish", you will come up with quite a few sites with interesting info on them.

Although listed as primarily herbivores (thus the algae eating), like most herbivorous fish, they're really omnivores, & will accept most flake & live foods. However, plant life is apparently their favorite.

I have three silver dollars that I've had for over three years now. They seem to eat anything and everything.It's hard to imagine them sustaining themselves with just algae. Although primarily vegetarian, mine eat flake food, shrimp pellets, tubifex worms, frozen shrimp and bloodworms. They don't really take food off of the surface, but, rather wait untill the food drifts down toward them. They will, however, pick at food that has settled onto the bottom. My dollars like to eat fresh lettuce leaves and I often take a fresh leaf, rinse it off and place it in the freezer for a few minutes. I have a small clip with a suction cup on it that I attach the lettuce leaf to and place inside the aquarium towards the lower part of the glass. The next time you cook some peas(canned or frozen), drop a few into your tank and watch what your fish do. If your dollars are anything like mine, thay'll go after them quickly. I do lots of gardening work in the summer and I feed my dollars the little worms that I dig up. In short, I believe that Silver dollars will eat allmost anything and it's good practice to vary their diet. Again, I can't imagine that they would thrive by picking at algae only.

I have kept Pacus (pirannah's peaceful cousin)that are like that with food. Anything and everything. They especially liked cucumbers! Also, they get quite friendly and almost tame. The grow before your eyes!

-PF

Have any of you tried feeding thawed or cooked chopped frozen spinach to your herbivores? I've read several times that herbivores love it, but have never tried it myself.

I'm going to try all these different fresh foods you are talking about...but I have to wonder don't they make the tank foul very fast? Or do you have the measuring down to a science and just put in enough for one meal and take out what's left really quickly a few hours later?

If they don't finish it in less than 5 minutes, scoop it out and try something else.

Have fun!

-PF (andy)