Places to buy Sodium Thiosulphate Pentahydrate

Does anyone know of any places in Houston, Austin, or San Antonio where you can buy small quantities of Sodium Thiosulphate Pentahydrate? My first thought was to try looking for chlorine neutralizer at pool supplies distributors, but so far none of the one's I've called in the Houston area have it in stock.

I buy it (as pool chlorine neutralizer) on Amazon. Very inexpensive.

a number of great sellers on eBay too....smallest you can buy is a five pound bag

Thanks, but I’d prefer to buy locally somewhere. There’s gotta be something.