For the bottom of a tank for bettas. I'm just asking cuz everyone has gravel or rocks, and I want sand for mine. I know it's no big deal, but I dont want my betta to be trying to eat the sand or sumthing Is it good for them?
Yes, you can use sand. Several members have it in their betta tanks. You can get it from places like Lowes and you have to rinse it really well before using.
I clean sand in a bucket by adding (hot) water and stirring al lot... then empty the bucket carefully, don't lose any sand! and then repeat the process, until you think the sand is clean enough to put in your tank...