gravel

I'd like to fill my frag tank (plumbed to display tank) with some heavier black substrate that won't blow around due to the powerheads. Is there anything I should keep in mind when purchasing something like this? EDIT: this brand is not reef safe. Anyone know where I can find something...

I have an established 40 gallon tank. Basically a frag tank at this point. I traded someone for a 77 long fresh water tank I am converting in to a display tank. I recently purchased two plate corals. I understand they do not like fine sand which is what I have for a substrate in my 40 gallon...

Our 125 frag tank has crushed coral gravel as substrate, chunks are about 10-12mm in size. Sand sifters are probably a no go, what can I put in here that will clean the substrate? I am unable to gravel vacuum it without taking all of the egg crate out which houses our frags. Pics of the algae.