Suggestions for PH and TDS water tester?

[Paul Mc]

I'm kind of new to all of this stuff, but I've noticied that my mounted plants have started accumulating white deposits on them. I'm assuming it's either salt or some mineral buildup.

So, I'm looking for a good but relatively cheap PH and TDS water tester. I'm not sure if that's all I need or not to determine what is actually in my water.

As a side note, none of my potted plants have this accumulation but I'm trying to rule out possibilities. Besides, I think I should start learning about water quality. Someone at one of the orchid society meetings commented that he/she always tests the water before watering and uses chemicals from PetSmart aquarium supply to alter PH to the specific needs of each orchid. He did not say what he did to increase or decrease TDS though.

I'm assuming to increase TDS you would use fertilizer with trace nutrients. I'm going to have to look at Gro-More's to see, but I'm assuming it does. This is what our local orchid society recommends for people on their orchids. But to decrease? I'm lost there, lol... Running through horticultural charcoal maybe?