[straightexhaust]

Ok so here the thing, i have bought KNO₃ of ebay to use to make model rocket engines and smoke bombs but the price to buy it is rediculous so i was wondering if there are some products at my local hardware/grocery store that i could extract it from and how.

No im not making explosives i just am making model rocket engines just enough to lauch my model rockets

[pantone159]

I have found stuff labeled potassium nitrate at my local grocery store.  (HEB, here in Austin TX).  I don't know how pure it is.

[billnotgatez]

Saltpeter is sometimes used as a food preservative. I cannot vouch for its purity.

http://en.wikipedia.org/wiki/Saltpeter

[straightexhaust]

anything else?

[constant thinker]

I wonder if you could ask for it from a pharmacist. I know you can get sulfur sometimes and tincture of iodine.

[billnotgatez]

straightexhaust-
Did you look at the link I posted?

[limpet chicken]

In the UK, you absolutely will not get KNO3 from a pharmacist, they used to use it in the 1800s (I have a few old medical manuals from that age, very interesting), but not any more, ebay has it usually, and its not expensive, alternatively, PM me, and I can link you to a source of conc. HNO3 itself, and making it from a sodium salt such as carbonate/hydrogen carbonate is trivial.

[Alberto_Kravina]

Here in Austria you can buy KNO₃(s)p.a. at the chemist's, and you don't need any special permission.

[niertap]

you could make it, from poop lol, or mix some ash and soil(compost). filter the liquid out and dry it.

[xxMIKExx]

Spetricide brand stump remover is 100% pure KNO3. Buy it at walmart-1 pound fot $5.