I put pool filter sand in my new 20 gal long. I bought one bag for about $15 and I still have well over half of it left with about an inch of sand in the tank (that's a 20 gal long, so bigger footprint than a regular, thus more sand) I disagree with the person who said you don't need to rinse it, although there is a possibility that some brands are cleaner then others. I gave mine a good rinse and I still had cloudiness when I filled my tank. I figured I'd let it sit for a few hours and see if it would settle but I got impatient after maybe 3 and just siphoned all the water out and then siphoned clean water back in. It took a long time, but luckily my tank is within siphon tube distance of my sink so no big mess. Still, I like it much better and I think it looks really nice with plants and a scattering of large smooth stones or chunks of rock.
Ok, so now I am all interested in changing my substrate to sand. I have some Vallisneria and a moss ball. I have never used any fertalizers and littlebittyfish mentioned that you should use root tabs if you use sand and have plants. Can you please elaborate on this? Would this be necessary with my plants? Also my tank has no lid, would a snail escape?
It depends on what kind of plants you keep, whether you need liquid ferts or root tabs.. Plants like amazon swords, vals (I think) need root tabs, they're little tablets that you put under the roots in the substrate because these plants take in more nutrition through the roots... I don't use these because I mostly have stem plants like cabomba, wisteria and bacopa... They absorb nutrition from the water not from the roots. For these I use liquid fertilisers.. They work great for me. :)
This is just my understanding of plants I could be wrong. You can check out Pew PewPew's plant guide, it will give way more info. :)