Ah, I love speed poison decks! I would suggest replacing 2 bone walls with 2 arsenics if you have them/when you get them.
First off, this is a fairly strong deck as is. Imo, 6 bone walls might be a bit overkill and might prevent you from getting a round of chrysaora poison in. Plus, unless you win in 6 turns, which is unlikely, you will have excess water quanta. What I would suggest is drop 2 bone pillars, drop the bone walls, add 2 arsenics and 6 freezes. That's just my suggestion though. There are PLENTY of other ways to build this deck. For instance, if you don't have the arsenics, you could -1 bone pilar, - 3 bone walls, +6 freezes. That being said, the build you have currently will still be pretty effective. These are just ways to alter it/optimize quanta production.