I am confused with my water quality in my area. I grow both orchids and nepenthes in my greenhouse so I got my water report for my area from my local water authority. The report says that a) Turbidity = 0.22 NTU, b) pH = 7.91,
c) Chlorine Residual = 0.91 mg/L (ppm), d) Hardness = 33 mg/L or 1.93 gpg (grains per gallon), e) Arsenic = 0.173 ug/L (ppb). (mg/L = ppm)
If my hardness is 33 mg/L or 1.93 gpg = soft, why do I get mineral deposit on the leaves of my plants? I water with RO but my mister and swamp cooler is Tap. Also, I get lots of mineral crystals on my swamp cooler. They did not give me the TDS but it is said that TDS and hardness is almost same. I don't use a water softener. Is this possible?
War. War never changes.
I'm not sure I'm understanding you right, but it sounds like you've answered your own questions. If you're using tap water in your mister, you'll eventually end up with buildup. Same thing with your swamp cooler. 33 PPM is pretty low, but if you evaporate enough of that water you're going to get buildup. How quickly do you go through water and how quickly do you notice buildup? If you quickly notice crystalline buildup in your swamp cooler when you're not going through much water, it probably warrants some closer investigation.
Municipal water reports are made at the municipal level. They can tell you what went into the system, but there's a whole lot of piping between the point that they measure and your faucet.