Water Quality: Hardness, pH, TDS. Where to draw the line?

[emmajs243]

Hey guys. My water is supplied from a well and I have been a tad concerned it may not be "orchid quality". Even more so, Cattleya seedling quality. (Idk if seedlings are specifically bothered by well quality water or not but i feel like I read somewhere that they might be??)

My water normally holds a TDS in the 450-480 range, pH seems to always be higher into the 7.45-7.60 range and besides knowing it is quite hard from the obvious signs, I am not sure the exact mineral content amounts....or how I could obtain this information. I have read you don't want your pH to be above 7.5 so there is my first concern. I also have read some saying that seedlings should be watered with water in a 6-6.5 pH range....is this accurate? I too feel like my TDS is quite high but honestly just don't know!

I pick up RO water regularly to always have on hand so I could dilute my water if needs be. I just hate to fertilize with pure RO water because I have read it is a lot easier to over fertilize due to the RO water not being buffered at all. Advice??