How to feed filter feeders?

[125gSW]

What can I supplement into the tank to help filter feeders?

I have a porcelain crab that has always been hidden but now has been showing himself more and I fear it may be from the water column not having enough for him to feed off of.

What steps can I take to make sure him and any other filter feeder will be fine?

 

[saltyfilmfolks]

Use frozen foods. Minor phyto.
Don’t spend a lot.
My last one was five years old and I never spent much on him, the current one I have isn’t now four years old and I have a red scallop that’s three.