How do you know that the water is not good? Maybe its fine and just has a dash or two of chlorine added so it smells a bit off coming out of the tap.

The thing to do is to look up the analysis provided by the local provider to see what it contains.

I was telling Whitecat in another thread that there was almost nil expertise about growing under lights here...same for the water, most of the locals just water with what comes out of the tap.

I have a fresh water tank because i have a lot of orchids. The tank came with a little sign UNFIT FOR HUMAN CONSUMPTION.

To get over the lack of minerals i use a complete (with minerals) orchid fertiliser every so often. But when you see orchids growing in the wild on a tree or a rock, you wonder how they eke out an existence without some kind soul providing said minerals.

Hi Jane - the pH will vary and is not related to the water quality. The stuff coming out of my RO system has TDS of 20ppm (very pure), but has a pH of over 8, due to the heavy concentration of limestone where I live. This needs to be adjusted, because it can affect fertilizer uptake by the plants (regardless of what fertilizer you use!)

As for suitable fertilizer, I think whatever you were using with the RO water in NY is fine!

My guy teases me affectionately about the orchids: I have to tell those "vegetables" to toughen up - after all, in the wild, they'd have nothing but a little water and monkey p-e.

Jane, it's gotta be a hassle to adjust to a whole 'nother orchid environment.

WC8

Arthur, the tap water smells heavily of chlorine and I'm not taking a chance. The few plants I hauled along with me have done fine with rainwater and MSU for RO. But we are now renting a small condo with no RO. I'm now collecting rainwater (I'll get thrown out of here with all my buckets) and just want to use regular fertilizer. I was worried about burning roots as most of my orchids are growing in open (rock, large bark)media.

WC you have no idea! Very humid outside. We are near the water and the wind blows constanly. They dry out in an hour yet the roots look good due to the high humidity. I repotted most to an open media to keep them from rotting. Phals are not doing well here, have lost a few and the others look bad.Just repotted them to try and save them. I'm not sure what is 'off' with them - heat, humidity or water, or all of the above.

Jane

It's my understanding that the MSU formula for RO/Rainwater has more micronutrients in it because the water is lacking. So it sounds like if you had a fertilizer like Dyna-Grow or Jacks which have micronutrients in them, or even the addition of seaweed, you should be pretty safe in using it.