Great greenhouse you got there, Stephen

They grow on cliffs in habitat. Must like the altitude

Thelocactus hexaedrophorus?

Just a thought, but has anyone ever seen a Circandra in cultivation? I know I haven't

Echinopsis. Subdenudata? Yes, a larger pot would be good. I think you'll like the flowers

I prefer to leave it if possible. Sometimes disturbed plants will abort their buds but often they don't. Sometimes the flowering as an additional strain that you don't need on a plant which may be a little under the weather and need to stay dry for a few weeks. But then if you don't mind losing a fl...

Its leaning away from the label

M. carmenae may form large mounds similar to M. plumosa but may also grow as larger individual heads which don't clump up for a long time. Seems to be much less trouble to grow although maybe a large clump would become tricky. Try soaking the M. plumosa clumps from the bottom every now and then so t...

The pH of perlite is essentially irrelevant. It is hardly soluble and will not alter the pH or nutrient chemistry of soil. Consider it inert in this respect, or neutral if you prefer although it is technically slightly alkaline. Vermiculite is also slightly alkaline, slightly more soluble than perli...

Roger, I think your "trolli" is actually a "celsianus" which tends to be less hairy.