Desalination is done through reverse osmosis, which yields very soft (mineral-free) water. Most municipalities add alkaline minerals to combat the sour taste of RO (carbonic acid from CO2 absorption) and to protect pipes, valves, etc.

I read it kills butterfly larvae so be careful when using it if you have butterfly larvae anywhere in the vicinity.

Yes, it kills caterpillars. That is why I mentioned to keep it away from the milkweed. Like any remedy, it needs to be used surgically... spray the affected plant, not the whole world.

I cant even imagine the plight of trying to grow these where you are at.

we take our great tap water for granted to be sure. still cant drink it but it wont kill ya plants :)

It's interesting RJ. When I first started with orchids (mass market hybrid phals) I was very concerned about our water and it's possible effect on the orchids. Ray and ES and others really helped me - I can't get a report from our water supplier. Adding a reg dose of Cal/Mag has made a big difference and I didn't have to swap to bottled water.

Everything in the garden now gets mineral supplements as well.

And we drink our tap water with no ill effects!

everyone I know or knew or who was always used cal/mag + products.

the peters excel cal/mag was my choice but I cant find it readily available. last bag I found the shipping cost more than the bag of fertilizer.

yes cal mag supplement is good stuff for all things orchids :)

I don't need a cal/mag supplement because there's so much in our tap water. I mix it with collected rain, about 20% tap water. When I add MSU fertilizer for pure water to that, or a typical 20-20-20 with micronutrients, I get pH around 6.0.

The product (Cordalene) arrived today (just 10 days, amazingly quick for us!). I've got in a supply of bottled water with a pH of 7-8. Gonna buy a new pressure sprayer tomorrow which will be kept solely for this.
Instructions say to thoroughly wet all leaf surfaces every 7 days for 3 weeks.
Fingers crossed for speedy results.