If your CYA is still in the low 30's, then use a float with 3" TriChlor tablets in it while you're away. Just make sure that the tablets are 99% trichlor and nothing else. It is perfectly OK to use trichlor with an SWCG. In my 16k gallon pool, three 3" trichlor tablets raise my CYA by ~8ppm and they take a good 10 days to fully dissolve from the float. Using that while you're away can help maintain some FC in your pool so you won't come back to as bad a mess if the algae starts in again. You can raise your FC above shock level before you leave with plain bleach and then throw the float in with a bunch of tabs and you should be good.