Certianly get a drop based kit...

Ben's is great (I bought mine last year) but the Wal-Mart 5 way will do the trick, but only has 2 CYA (Stabilizer) tests in it - probably sufficient for one season really.

I also agree that the bubbles are likely from the algecide. If you are keeping your water properly balanced you won't need very much (if any at all) algecide. I usually have to add a quart mid summer to fight of a little persistent algae, but that's about all. Only use the 60% Polyquat type algecide - stay away from anything else.

By the way - the strips are notorious for giving spotty test results at best.