thanks for the quick response! I notice that the Haworthia tips, some of it are beginning to turn brown, like dying. Is that because there's too much sunlight? If you took the pot out of the store and put it on a south-facing window, too much sun is a possibility. In that case, it can scars the pla...

From left to right:
1) Parodia, maybe magnifica or warasii
2) Haworthia, probably attenuata
3) Mammillaria elongata

@Arizona Fero - What are "many heads" (2) and (3) ?
I have a feeling that 3 is E. grusonii but how would this happen ?

It's either warasii or magnifica but your plant doesn't seem to have the blueish flesh of the magnifica. I don't think it's misidentified but i'm no expert.
My P.warasii also grows tilted. If you grow it on a windowsill, it's probably trying to reach the light, and there's not much you can do.

All in all, the finer the sand, the worst...
It packs up your mix, doesn't help to have a good air flow and can eventually clog the pot.

The green stripes could be the result of a cross between myriostigma and myriostigma v. nudum. I'm no expert in the astrophytum world though.

Lovely. I really like those white blooms. Fosterianus' flower is all about smooth curves. I wish I could smell that.

It's a cactus. Astrophytum myriostigma.

Wow. Congratulations. Quite a success.
Baldanium seems quite a good candidate for crosses in the genus: variable color and flowers at an early age. This makes things even more interesting.

Oh and, I like your yard.

Mmm I see space for further expansions.

RichR wrote: I think that going from watering them with pH 9.8 water to pH 5.5 water must be a shock to them.

Ouch. 9.8 Now that's hard water.
No need for Gaviscon, have a glass of tap water instead!

Second one looks like Hamatocactus/Ferocactus setispinus. Can't remember the exact taxon.

Pilif wrote:sounds allmost like the reddish lines that appear on about every ferocactus seedling.
But pics would help indeed.

After seeing the pics, I second Pilif and wouldn't worry.

Keeping these two plants on the shelves makes no sense as it increases chances of propagation to their own stock and subsequently, to buyer's. Already seen some smart*ss up here trying to sell me mealy-fuzz as cactus-wool! Clever enough to know some cacti have whool and unable to spot on mealies? I'...

Very neat. I especially like the GH flooring. I would also be interested to know brand & dimensions if you can post the info.
That picture of the mamm bloom is very nice.