Copper Sulphate (CuSO4) Solution as a Fungiside ?

[handiko]

Hello everyone.

I have several hybrid Phal seedlings with sphagnum moss medium. With the day progresses more and more into August, here (in Indonesia) the rain becomes more and more often. The implication is my seedling medium become moist longer than before. Now I only water it about once every week, while a few weeks ago I watered it twice a week. So, as a prevention, I think that I need to spray my seedling with some fungicide.

I have some copper sulfate pentahydrates crystals (CuSO4.5H2O) from many years back still in good condition. And I read somewhere on the internet that copper sulfate solution can be used as a fungicide on crops.

My Question is: Is it true? Can I use copper sulfate solution as a fungicide on orchid? Is there any side effect? What dose should I use?

Any answers are welcome. Thank you.