War. War never changes.
Looks like plastering sand is really just a grade of sand size (125-250um). I suspect that most of the sand used is typically a bit larger, but I've received plants with similar or even finer particle size sand before and the plants seemed plenty happy. That being said, I imagine that a 1:1 with peat may end up with something that is a bit dense over time, and it sounds like you've repotted these anyway. For the Pinguicula you've used such a small ratio of it that I don't see it posing a problem.
All this is, of course, assuming that you're dealing with silica or quartz sand. A concern is that you may have limestone (CaCO3) sand which keeps things on the alkaline side, while we generally tend to keep CP substrates fairly acidic. People will frequently test their sand with an acid which will create CO2 gas an visibly/audibly fizz. People frequently use vinegar for this purpose due to its ease of availability. If you want to prove to yourself that vinegar is sufficiently acidic, drop some on some baking soda or an antacid tablet and behold the fizz.
---- Semi-relevent rambling follows.----
As a general note, Warren's suggestion to look things up in the MSDS (or SDS as they're arbitrarily changing the name to) is an excellent one! This goes for most materials or chemicals you buy. Sometimes certain information will be generic or outright wrong*, but the contents information should always be correct.
*For example, I have a bottle of very fine mesh Palladium powder which is rather flammable. In one section of the (M)SDS it correctly suggests using a CO2 extinguisher to put out fires. In another section it incorrectly suggests using water. And for almost all chemicals the medical response section will just tell you to move to fresh air, rinse eyes for 30 minutes, do not induce vomiting, call a health professional. These sheets have the unenviable position in the tug-of-war of preventing litigation for insufficient information and preventing litigation providing suggestions that someone can use to hurt themself.
Last edited by Est; 01-01-2016 at 02:54 AM.
To be on the safe side you could just use some vinegar acid in a glas and pour some sand into it. If you see a stream of bubbles coming up there is probably lime present. If not its ok.
Thank you for your response. I really appreciate all the detail
Originally Posted by Est