Probably the closest you'll come to a walmart here in Gran Canary is Carreflour.
They pretty much have everything from clothing, sheets, to groceries.
Downside: They sell computers compeletly out of date. The latest models you won't find here. Buy online!
Bonus: They have an awesome selection of beer. I can find my dark beer here and only here!
However it's kind of a hassle to come here. You have to enter a mall to get here. A dreaded experience. Then to enter the store.... you have to walk ALLL THE WAY to the back end, then walk ALL THE WAY BACK to get the stuff you need. If you try and make a shortcut... you'll get yelled at.
But... when in need of brand name products and cleaning supplies... a bargain can be found here. read more