Robert's sells a version of MSU fert (which is urea free) which I used to use, but it is not low K. It does have some calcium and magnesium, but at levels lower than the K. But if you mix it in tap water rather than the recommended RO water, the balance of K to Ca and Mg will be better. I used it for developing my original low K strategy by "diluting" with calcium nitrate and epsom salts, but have since switched to the K-lite material that Ray got Greencare to make for us.
Although many of us were putting some of our rambling parvis in baskets, for quite a while, it wasn't a common practice to putting other Paphs into baskets, especially with media other than bark or chc based mixes. About a year and a half ago I started moving most of my paphs over into baskets. See a thread called "Mark this date for basket culture". I think Dec of 2010.
Any way I also moved lots of my multis into baskets. Roths, stonei, supardii, sanderianum, kolopakingii, gigantifolium, anitum, randsii..... mostly with very good results. Recently I should note that the ones that did best had more limestone gravel than moss, and I've reduced the moss to rock ratio in several baskets.
One of my supardii (which also has a very red pouch) came from OL too. Maybe they're kin:wink: