Well, I found the right cartridges at a local store and that made all the difference.

I will try to clean the old ones with bacqua-clean and keep them for the conversion if/when we do it towards the end of this year or beginning of next season.

I have a pool party in 8 days and I'll be out of town for 6 of those days.

This seemed like the most viable solution at the time.

Thanks for the feedback.