sand query

hi,

i currently have fine silica sand in my 6ft & think it is the cause of some of my fish flashing as after observing the fish for a few hours i noticed it is only the species that spend the majority of their time at the bottom of the tank, whereas the species that spend their time in the open water top part of the tank dont appear to flash at all.

the sand is extremely fine & the water flow is strong causing tiny particles to be suspended 1-2" above the bottom, i have also noticed that it seems to stick to the fish when they brush them selves on it.

this must be irritating them & may cause damage due to rubbing against rocks etc.

i have hermit crab sand in my 4ft which is a coarser grade, much heavier than the silicate & doest stay elevated in the water due to strong flow.

i am getting a new tank in january so am looking into changing the substrate when i set the tank up & wondered if any one can recommend a sand that wont irritate the fish & isnt so fine as silica, but not coral sand as this will break down over time

i am thinking of using the hermit crab sand!!!

also i would like to have some giant vallisenaria plants in my new tank as i like the addition of plants & i have read this particular plant is found in lake malawi.

i will plant it & leave to root for 2-3 weeks before adding the fish to give it a higher chance of survivng, has anyone had success with this plant in a malawi set up?

thanks.x

I have #2 sand blasting sand in my 90 gal, paver sand in a couple of 55's, and Quckcrete play sand in some of the others. The plants seem to grow really well in the paver sand. I've had the best luck with Crytocoryne wendtii, the fish never bother those at all, and dwarf chain sword. Less well results with Amazon sword and
Java fern.
If you use the paver sand you have to wash, wash, wash it, though.

I also use sand blasting sand in all my tanks. Very cheap, very clean, looks great and the mbuna loves it. Alot of members on Swedish forums use vallisenaria in there tanks with much succes.