Empty 10g and dwarf puffers... a few questions

[lilyrazen]

If I were to get dwarf puffers, if could only get two. So, I'd probably only get one.

With just one DP in a 10g, what could I put in there with it (if anything at all)?

Also, it'll probably be a while before I stock it. I'm planning for now to take some of the gravel and water, and transfer it to my new minibow for Vilkas to keep the beneficial bacteria.

If I were to get a DP (and many tankmates), how long should I cycle the tank for? I've had the tank running for two years and I've never packed it away, but (because I can't adopt out my goldfish and I'm not allowed to put it in the 10g) I might have a goldfish to put in it while it cycles.

I've also heard they need sand for their delicate skin, so could I use playbox sand?

Also, the filter cartridge I have now has only been used for about 2 or 3 weeks. I assume there isn't, but is there any way to use it or save it after I empty the tank?

[Olympia]

Nothing. No tank mates with these guys, it's too risky... You could get 3 DP's, but they are monsters to other fish.