Good idea about the BB on the DW, might be a small amount, but could help a little.
I posted a response from your photo / album pic comment re the Pom Pom crab.
Poms might be too small and become a snack for the Silver Dollars when they grow.
Also more FW
Pom crab info in the description.
Re: the SW
photo you commented on...
If you love the Pom Pom SW
crab like I do, then consider a little nano 10G SW
Macro algae Invert tank with Anemone / aka Sexy shrimp, Micro Brittle stars, and Rock Flower Anemones and a little Yellow Clown Goby
Was one of my most favorite fun tanks
nano with Rock Flowers and a Anemone Shrimp
New to FW fish? First tank in a long time or EVER??? Need some info on keeping fish?
Start here - Aquarium Advice Article
FW Favorites right now Clown Loaches, any shrimp - SW Vase Red Mangroves