Was it this?
I think it's part of that seed club on the GW site, I'll have a rummage
I haven't used it I've got a couple of others that I use, quite useful.
Mostly the seed site, I know it better, used it for years. Lots of interesting info as well as the germination thing.
Hardy herbaceous, shrubs and trees are what I know about. Veg, half hardy, tender, not a clue. But finding out more by the day on the forum
I use a mix of seed, multi and grit with grit on top. seems to work for the long term germinations that are a lot of mine.
I have one single aquilegia seedling. I'm expecting action soon in a lot more of those pots. The forecast says warmer here in a couple of days.
I'd be surprised if those aquilegias failed you.