How many sand sifters to a tank?
 

I was wondering how many sand sifting gobies I should put into my tank. I have about 200 pounds of live sand in the 260g. I have a yellow headed sleeper goby and a dragon goby. Of course they have the two areas in the tank they reside in and do not venture very far from them. I find they keep the sand turned up which helps me out a lot. However, I would like to add a pair of orange spotted gobies to the tank for more sifting.

Is this doable, or a bad idea?

These fish are eating the critters living in your sand bed.
Your tank is large enough to accommodate more and you can also drop in shrimp pellets for them to eat as well

I was concerned that they might compete for food, or two gobys would knock down at sand critters too quickly. I decided not to go with the pair of gobys today since they were a little too small to be safe from my puffer. Thanks for the info...