fishfreak2009

How many 50 lb. bags of Pool Filter Sand would I need for a 90 gallon tank to make a 3.5 inch deep sand bed? Also, can you siphon the sand with a gravel vacuum?

an aman

soldieroffortune1974

That would depend on the actual dimensions of the aquarium,a thin, tall aquarium would need less sand than a wide, shorter 1 to make the sand bed 3.5 inches deep. I would estimate 3 to 4 bags.Start with 2 and spread it out evenly and go from there.

You can use a gravel vaccuum on the sand,but you don't stick it down into it and move it around like gravel. Keep the vacuum several inches above the sand and wave it creating a current and it will raise the debris off the sand and suck it up.It takes a little practice,but it's not difficult. You'll also want to get a long fork,like a BBQ 2 prong fork to stir up the sand every once in a while to release trapped gasses that can build up.

harpua2002

http://fish.bakerweb.biz/calculators.html
According to this, 158 lbs., assuming that you have the standard 90 gallon (48x18x24). I used 150 lbs. in my 120 gallon and it ended up being pretty deep.

You don't siphon sand the way you do with gravel. The detritus tends to stay on top of the sand, so just use your gravel vac to stir the gunk up off the surface and vac it out of the water column.