Unlike Phrags, I don't think that Paphs are all that sensitive to water quality. Many grow on limestone cliffs. People who live in pure-water areas add marble chips or dolomite lime as top dressing to add calcium and raise pH. I do know that at the Huntington Botanical Garden in southern California, with a very significant Paph collection (one of the largest in the US), that they use well water (which ranges from 200-800 ppm TDS, primarily calcium bicarbonate) for the Paphs. They have plenty of RO water capacity, which is used for the rain-forest plants and anything else that needs it (resources are not an issue) Most of the Paphs clearly are quite happy with the high-TDS, high pH water.

A small Roth will grow very slowly. People who grow them really well report they take 7+ years to flower from seed. It takes a small plant longer to recover from drying out than a larger plant. I would say continue good care and they will grow.

I wonder whether watering twice a week is enough. They should not dry out, especially when so young.

By the way, Paphs excel in semi-hydroponic culture. My small Roth seedling is doing well in S/H, except sometimes I can't water often enough. And a rat ate the newest leaf down to the crown two weeks ago. It's grown that leaf out about 3" / 7.5cm since.

I took notes on a Paph talk to our orchid society given by Brandon Tam, the orchid curator at the Huntington Gardens in Los Angeles. Use the search function in the top purple menu bar and input Brandon Tam. You will find the thread.

I have wondered this myself too about the watering. I really have never felt like I am getting the potting media right because when bark media is new it doesn't seem to absorb water well until it has a little time to break down and I think that I am not watering enough. I have a fan and hope I am giving enough air.

pismane, my advice is that you go to youtube right now and type in Ed's Orchids (actually I will put the link below) and start from the beginning. Ed is a true Paph / Phrag Jedi Master with over 40 years experience. You will learn a lot from his videos.

Eds Orchids
- YouTube

Awesome! I can't believe I haven't come across this yet.