RO or distilled or ZeroWater?

[Lucille]

First, I'm going to get the facts, because all local water systems can differ. My water might be perfectly OK for the orchids. I sent off for a TDS meter which should be here Friday.
I have set up my plant area and I water in place. I could take the plants to the sink and flush water through the media but not often, I am a senior and it is difficult for me.

At what level, in your opinion, of dissolved solids reported by the TDS meter, should I consider looking into a treatment method to remove those solids before watering?