Need help with a substrate please.

I am setting up a 90 gallon tropical tank and I need some suggestions on what type of substrate I should use. I plan on stocking with a small silver arowana, 2 Blood Parrots, a Flowerhorn, and some sort of bottom level fish. Most likely a catfish of some sort. I was thinking of white sand, but I have never used sand as a substrate before. Any suggestions would be appreciated very much.

there is a sand that you can find at your nearest home depot. It is called pool filter sand but be prepared to rise the sucker really will. A good trick to do this is by getting yourself an old pillow case and fill your sand about the quarter the pillow case and useing a garden hose, keep filling until the water runs clear. If you are looking for a sand that will produce a high ph in your tank, try the carbi-sea agramax sugar sized sand and the same will apply when rinsing the sand..... PILLOW CASE TRICK!!!!! I hope this will help you out. When it is all said and done, It looks fantastic!!!!!

Carib sand could be a good choice.

I sure hope you don't mind me asking, but do you have a much, much larger tank in mind for the Arowana?

I'm assuming you are going to use a canister filter vs a hang on the back but at any rate it is worth mentioning that if you are going to run any H.O.B. filters, make sure to keep a sponge over the intake. Otherwise the sand ends up messing up your impellar and ruining your filter before its time. Usually canister filters would filter out any sand that is sucked in before it ran into any impellars...

african cichlid sand, or pool filter sand. but be careful with pool filter sand. make sure it doesn't have silicins in it or you will have a bad algae out break in the tank.