[nabee24]

I have about 40 snails and 20 hermit crabs in my 90 gallon tank. I have noticed that there are piles of pellet looking things on top of rocks and sand. I think they are droppings. I'm having a hard time siphoning them out. Should I get a powerhead. I do have a protein skimmer but doesn't seem to be doing the job.
I also have algae growing. I wipe it off with the magnet but every morning I notice the screen of algae on the glass and sand.
HELP

[leebca]

WELCOME TO REEFLAND!

Until you are sure what it is you're looking at, you might not want to worry about it. You mention snails and hermits, but nothing else. What else is in the aquarium? You might want to provide some additional background information about your system.

Regarding algae. . .most need nutrients like anything else. This is a good read in general regarding nitrates:
Nitrates - Origin & Controls

For additional help here, we'll need to know some test kit results and system information like: ammonia, nitrite, nitrate, phosphate, pH, lighting, etc.

[Reefland]

I think I know what you are talking about, and if we are talking about the same thing, it would be snail waste. However if it is accumulating on the rocks, you need to increase the overall circulation in the tank to hold that waste in suspension and allow it to be filtered out.