Quixote Posted January 29, 2014 (edited) Just wondering if I could crush some blackboard chalk sticks to add to my Lophophora soil? Or is it a different type of calcium? (I only have one little Loph in a pot, so don't want to buy a huge bag of chalk if I could just use a bit of sidewalk- or blackboard chalk) Edited January 29, 2014 by Quixote Share this post Link to post Share on other sites
Foo Posted January 29, 2014 i wouldnt. Who knows that they add to "chalk" now days. Nothing wrong with limestone or crushed shells 1 Share this post Link to post Share on other sites
Auxin Posted January 29, 2014 Blackboard chalk is usually gypsum, useful if you want to severely inhibit cactus growth, lol. 2 Share this post Link to post Share on other sites
terracottacactus Posted January 30, 2014 (edited) Edit: Don't know what I'm talking about Edited January 30, 2014 by terracottacactus Share this post Link to post Share on other sites
Philocacti Posted January 30, 2014 Blackboard chalk is usually gypsum, useful if you want to severely inhibit cactus growth, lol. 2 years ago I limed my entire collection with hydrated lime and it stalled until last fall or something. I've repotted my entire collection this winter to make it ready for this growing season Share this post Link to post Share on other sites
naja naja Posted January 30, 2014 i was under the impression chalk was CaCo Hydrated lime is CaOH and is way to strong for cacti Share this post Link to post Share on other sites
Philocacti Posted January 30, 2014 Yeah... It's stunned my whole collection. Now I got a ph meter and I'll find my way to get dolomite and I'll see how things progress next growing season Share this post Link to post Share on other sites
