calcium and magnesium

[caseydoll]

Thanks Ray for that link! It's so crazy how everyone has totally different experiences with chc! I guess it depends on your growing conditions. I use a chc mix with every single orchid I have that isn't in s/h. I've been using it for over a year now and have had great luck with it. My phals especially seem to love it. The ones that were doing nothing at all in bark seemed to come to life in chc. It absolutely does not stay too wet or soggy for me. And that's even with 70% plus humidity in my orchid room. But reading that makes me a little nervous. I hope everything doesn't go downhill in another year! It's probably like sphag. People have very strong opinions about it, they either love it or hate it but it really is just dependant on their growing conditions and how often they water.

[orchids3]

Ray, Not active on that forum - but I do pretty well with CHC but do take the precaution of soaking and draining the CHC several times before I use it. Some CHC does have salt in it - It can be soaked out. Adding a little Epsom salts or Calcium nitrate to the soak water helps according to some but not my chemist friends. Bet your slipper forum addresses ways to prepare CHC - will plan to read your reference asap - you give good info.

[kavanaru]

Originally Posted by Ray

Both garden lime and dolomite have dissolution rates that vary greatly with temperature, which tells me that you really don't know how much Ca and Mg you're supplying at any one time.

Be wary of CHC for some paphs. If you'll bop over to the slippertalk forum, you'll see a long thread on the subject:To Chc Or Not To Chc? - Slippertalk Orchid Forum- The best slipper orchid forum for paph, phrag and other lady slipper orchid discussion!

I have not seen the problem myself, but it never hurts to read of others' experiences, so you can be on the look-out.

Ray, you as the most experimented S/H grower (and I assume MSU fert too), what is your experience with providing extra Ca Mg? I have read somewhere that both MSU and Peter Excel had enough Ca Mg supplement that an extar source of this nutrient was not necessary, not even for calceolus type Paph (but cannot find that source of information anymore, it was loooong ago )

Do you grow these Paphs? Do you add extra source of Ca Mg?