Sand size for various substrate critters

[yanni]

Hey all!
I’m currently about to redo my tank, and was given a bag of sand for free of 2-4mm crushed coral and sand mix. It’s all cleaned, never been used, and since it’s free I wanna use it. But I plan on keep snails that love substrate, as well as other critters, like nassarius/zombie snails, conch snails, maybe an urchin or sand sifting star, as well as some rock flower anemones.

is this sand size too coarse for them? Or should I opt for something smaller and finer? Pic attached for general reference

 

[blaxsun]

I'd probably need to see an image, but depending on the fish/invert smaller is always better (I have Oolite, which is probably the smallest but also the biggest PITA).

 

[yanni]

I'd probably need to see an image, but depending on the fish/invert smaller is always better (I have Oolite, which is probably the smallest but also the biggest PITA).

Size of reference next to my thumb, which in hindsight probably isn’t ideal haha as it’s a thumb, but you get the idea

 

[blaxsun]

I think that'll be fine for the critters you mentioned. It may be too thick for wrasses to bury in or too large for fish like sand siftinggobies.

 

[yanni]

I think that'll be fine for the critters you mentioned. It may be too thick for wrasses to bury in or too large for fish like sand siftinggobies.

That’s okay, I don’t really plan on keeping either. Keeping my fish stock to two clowns, and a lawnmower blenny eventually, maybe a dragonet. As long as it’s fine for the snails, and maybe a star, will be fine

 

[Subsea]

The reason smaller grains are a PITA is because currents blow oolite sand all over. I use 2-4mm CaribSea Crushed Coral and have no problems with detrivores that recycle detritus into live food for hungry mouths. This grain size allows amphipods & copepods into substrate matrix to consume detritus. For 20 years, I used Jaubert plenum with 5” dsb of 2-4mm crushed coral. In those days, my focus was on natural nitrate removal using reducing oxygen conditions. Oxidizing bacteria in the “facultative zone” ( low oxygen enviroment requires bacteria to break apart the oxygen molecule in NO4 and release a free nitrogen gas molecule).

Nowadays, with a mature reef, I add ammonia to keep up with nitrogen demand.

Five years ago, I reduced sand bed from 5” down to 2” and added pump discharge into plenum to establish reverse flow undergravel filter, using the plenum as a cryptic zone.

 

[vlangel]

I also have a coarser sandbed and my nassarius snails do fine. I do have a bag of oolite mixed in but like was already stated, all oolite can blow around creating an annoying sand storm.

I also do not keep wrasses so not sure how they would do.