Algae on sphagnum

Liz, if you mean clay pots with holes or slits on the sides, "orchid pots," then yes, the root zone should be getting plenty of air as long as the sphag isn't packed in too tightly and you're not using pots that are too big for the plants. A little algae on the strands of sphag will make no difference at all, and is nothing to worry about. The only time it becomes a problem is if it grows so dense that it blocks air--but with slitted pots, that won't be an issue.

We grow in plastic and don't use slitted pots because it's a nightmare to extract plants from them once the roots have started to grow out of the slits. For that reason, I like to repot when the sphag goes seriously green with algae. If it's going to happen, it usually happens here after about five or six months, and by then, the sphag's antifungal properties have pretty much worn off anyway. The algae growing is a visual cue for me that the medium is no longer fresh. In your case though, with your particular growing conditions, that may not be an appropriate visual cue to use.

To be honest, I've never seen algae grow on fresh sphag that wasn't exposed to the air and kept damp for some time, at least several months. Did you use a new bag when you repotted? (Just curous here, there's nothing "wrong" if you didn't...)

In humid conditions (i.e. a basement), a good way to store media *long-term* is in grocery brown bags. Any excess moisture can usually dissipate that way. In normal household conditions, plastic bags would be fine.