Pot height for smaller orchids?

[Ocelaris]

I have a couple of orchids in semi-hydro that seem to be drying out, or rather not doing well and I am concerned that they're over potted. Basically the wicking action to the top of the 6" tall pots (4" wide) is not enough to get nutrients to the new roots that are not deep down in the pot.

Has anyone else had this experience?

[Ray]

The problem is likely insufficient humidity - the liquid is evaporating before it can "reach" up far enough.

There is a balance between wicking and evaporation rates. Evaporate slowly and the wicking action can keep up. Evaporate quickly and it can't. The depth of that "dry line" will vary with seasonal conditions.

If you cannot increase the humidity, simply water more frequently.

[Ocelaris]

here is what I'm referring to, my Phal marae only had 2 small leaves, but it's only made one, and it's new roots are barely making inroads.




And here is my encyclia which is a much smaller root, and it also seems to be too dry:



Here is my latest humidity/temp chart... blue is temp, red is humidity... I can increase the humidity some, but I Think I will cut down the plastic pot this weekend so it will sit closer to the reservoir. I am watering every 2-3 days... basically when the hydroton pebbles appear to have lost their moisture content but there is still plenty of water in the reservoir.

I'll admit, I moved the plants to semi-hydro as soon as I got them. The encyclia had a scale problem which has been resolved for a month, and there was a fungus problem because I was watering too frequently. This also has been resolved with a little physan 20 (RD-20) about a month ago, and every other week I use a little physan. So I was worried about it being Too humid, but I have a good amount of ventilation, and it's a semi open environment.

You probably answered the question outright Ray, but I like to give plenty of details so others can benefit and contribute. Thanks

tank:

[Buds!]

Hi Ocelaris,
I had the same issue with smaller/seedling (phals) in s/h.

Here are a few things few improvements I have made for my s/h seedling set up:

1. Reduced the wicking distance with smaller containers. I am using plastic cups for seedlings- 1:1 (height to drainage holes: diameter of container)

2. I am using Hydrotons. For the area around the roots, I have chosen smaller pellets, therefore increasing the wicking surface area.

3. Increase humidity (I agree with Ray)- 75- 85% for my phal seedlings.

Here's a photo of my babies, they are 1 months old and have been transfered to s/h for a few days. They are doing better in s/h than in sphag moss.



I hope that helps !