By the bye, a blue ring typically only shows the markings under stress, so if an lfs has them and they are that visible, they must be really, really, really happy.
Please don't misunderstand me, I happen to really like H.L.'s as aquarium animals. It is just that it would be like someone on the herp boards stating that "they aren't sure if they bought a cobra or not, they have never kept a snake before" sort of thing.
hmm.....ok, so since this child seems to want to keep his/her pet, despite the advice so far, maybe he can help us out with some information:
About the blue rings: all over the body, or just in a couple of places (like this one?)
If its just two blue rings then you should be fine.
If you've managed to score a genuine blue-ring of the lethal kind, I think you should give it away to someone who can keep it safely (best option), or (as you seem to have decided already, despite being advised against it), if you're going to keep it at least make sure your parents/guardians/etc. know how dangerous this animal is, so if you are unlucky or foolish enough to have it bite you they can take action quickly (you might not be that lucky though....). If you don't have it already you need to get a very, very secure tank lid. And make sure every single person who will be in your house knows that you are keeping an extremely dangerous animal.
Don't hand-feed it at all, not just 'less often'.
Seriously, please find that camera cable so the people here can give you correct advice.
I think this is either a recipe for disaster or a troll....
He is white at rest. He has a mantel at about 3/4 of an inch. The people at the store said that someone sold it to them in side a tank and that they said it was a "dwarf". I don't hand feed it, I toss the food in the tank and it just finds it.
People haven't had the best luck with just weight, since sometimes the octo can still squeeze through a crack without having to lift so much. Using duct tape as well is probably a good idea.
As Roy said, it sounds like it's possible, maybe even likely, that the octo isn't actually a blue-ring, but please treat it as one until you're 100% certain. I'm glad that you're no longer hand-feeding, at least, but I'm still concerned that keeping a lethal, escape-prone animal in your bedroom is really a recipe for disaster.
I remember how frustrating it is to be your age and get told by adults that you're not capable of handling responsibility, and reading between the lines, it sounds like you're sometimes frustrated, but keep in mind that Greg would say the same gruff thing to anyone, of any age, who isn't prepared to keep a dangerous animal, and we're all concerned for the safety of you and your family rather than just trying to be snotty. It's a rough situation when you are misled about the nature of an animal, particularly one you've become attached to...
Please do your best to find your camera cable so we can get the ID resolved ASAP.
edit: note to other blue ring experts: does anyone have good pictures of the various blue-ring species when they're not displaying their rings? It does seem like, while they don't show them all the time, they normally show them every few minutes when they're active, right? At least that's the impression I have from the videos...