Here is a Gymnocalycium for which I have lost the label. I think it was multi something, but as it has finally flowered I thought I'd ask the more knowledgeable to comment. It's in a 3ins square pot.
I think I'd be adding vinegar by the litre here if I were to use tap water, the water here is so hard that we have to use salt in the dishwasher even with combination dishwasher tablets. I have never tested my rain water's pH.
As to the name, I just checked my database and I acquired it from Southlands and it should be Lau 1377. Apologies for the above mistake, I was going on my memory as the label had faded.
Many of mine seem to be the same - I think they have been too dry for too long. I had one that flowered beautifully last year and now looks dead. I usually use Dr Alcock's mix which is acidic, but I think a repot is a good idea and I'll see how I do. Thank you for starting this thread
I have a Stenocactus Lauii which flowered beautifully .. After I removed the dead flowers, I realised that mealy bugs had set up camp in the crown of the plant. I have treated them with Bug Killer, and they are dead, but the wool is now matted. Advice, please, on how to remedy this.