Safe Tank?

So I found my old fish tank and started cleaning it for my ballpython.

I want to use this tank because of the size and wand that is already in there, the problem is that after extensive cleaning of the wand some algy (hope i spelled that correct) remains.

I've poored over 100 gallons of boiling water over the wand but is does not home of. I hope that based on pictures you guys can tell if the tank is safe to use.
http://images.tapatalk-cdn.com/15/07...2743a0f851.jpg
http://images.tapatalk-cdn.com/15/07...1657b895b8.jpg
http://images.tapatalk-cdn.com/15/07...c665411b6c.jpg

Verstuurd vanaf mijn HTC One_M8 met Tapatalk

Is that sand and pebbles in the last pic?

I think if it were me I would take the foam background out and scrub the tank with CLR or the like. Hose it out and then get new foam inserts.

Dried algae shouldn't hurt a snake, especially if it's in small amounts (I can't even really see it from the pics, so you're probably good).

As KMG said, the sand and pebbles are a problem though. Especially sand. It can get into their heat pits and mouth and irritate scales.