Substrate that doesn't cloud the water?

[AndyL]

Quick question...

Anyone able to recommend a substrate that doesn't cloud up the water when dug in? My pred tank has suddenly gone very cloudy since the introduction of the dragon wrasse - his constant digging / burying himself is stirring up tons of particles making it awful cloudy. (Before it's suggested, yes I have checked NH3/4, and NO2 - not a cycling issue).

Currently I've got some Caribsea aragonite, the plan would be to add more over top of the existing (the wrasse needs more sand anyway). Shouldn't be any issues dumping in the new sand over top of the old right?

Andy