How much sand?

Just use play sand or pool filter sand. Both are fairly cheap (less than $10US for 50lbs). You should be able to find play sand in Lowes/Home Depot. Pool filter sand can be found at a swimming pool place. Make sure you rinse the sand very well before adding it to your tank.
 
Pool filter sand is a little heavier, so it doesn't stir up so much. Makes it nice during cleaning and water change time.

About 1.5 inches of sand is optimal for most aquariums. If it's too deep, you run a bigger chance of poison gas building up.
 
I just bought 2 50lb bags of silica sand from Menards for $4.16 per bag. It's already washed (states that on the bag) which is nice. I took some out and rinsed it in a bucket to make sure it's really clean and it was. Added water to the tank (75 gallon) and there was virtually no cloudiness at all. I put in one of the bags and half of the other and that gave me about an inch and a quarter all the way around.
 
I just bought 2 50lb bags of silica sand from Menards for $4.16 per bag. It's already washed (states that on the bag) which is nice. I took some out and rinsed it in a bucket to make sure it's really clean and it was. Added water to the tank (75 gallon) and there was virtually no cloudiness at all. I put in one of the bags and half of the other and that gave me about an inch and a quarter all the way around.

Thanks, I'll try to find some
 
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