The Distilled water from walmart is the purple cap not the green cap.
Don't use that in your tank please.
dude with all due respect ehre is some serious advice. just buy a 100$ r/o unit off of ebay and start the hobby after you get it. it will save you some serious money and let me also tell you about that distilled water, i have made better water then poland springs has with my r/o. (props to pseudo). i have tested there waters just to check and see and have found phosphates. dont bother dude just save your money up. stingnyc is selling one of the best ones on the market. if money is the issue i am sure he can work somthing out with you. just an fyi. check out the for sale forum