How often flush the container
 

I'M new to the forum and rather new to S/H. Started about 1 month ago to convert some plants of my small collection. I care for them with Rain Mix and Kelpak. Til now all is fine and they are still happy.

Some questions:

I was astonished how fast the water evaporates or is used by the plants, I have to refill the reservoir every 2 to 3 days. How often do you flush the reservoir?

Two holes in the container, am I right that the second hole is just for safety in case one hole is blocked by leca?

It should be done at every watering.

Fill the pot quickly to the top and let it drain.

Yeah, that’s pretty much the reason for 2 x 6mm holes versus one, larger one.

Thanks for your quick answer, Ray.
But isn't it enough to refill every 2 days and flush maybe after every 2 weeks?

In my opinion, no.

As the water evaporates and is replenished from the reservoir, minerals and plant wastes concentrate in the LECA. Once they are absorbed and the LECA starts to dry, the deposits are very difficult to redissolve and remove. By flooding the pot with dilute nutrient solution at every watering you flush then saturate the medium, and refresh the chemistry of the reservoir.

When S/H orchid culture was first introduced, some folks routinely topped-up the reservoir, flushing only about once a month. Within a year or two they started noticing a general decline in their plants.

Others did the "flood-and-let-drain" technique at every watering and had no such issues.

Ok thanks a lot.

Hi Peter, and welcome to Orchid Board. Ray is a wealth of knowledge regarding semi-hydro growing. Following his advice is how I learned to grow in SH, and I now use that method almost exclusively.

A couple of things I do differently... I no longer put two holes in my containers. Ray developed the two hole system because he had an automatic watering system, and would be gone traveling quite often. If the one hole got plugged and didn't drain, problem. I drill a lot of glass for containers, and don't have my watering system automated, and find two holes unnecessary.

I use RO water, and flush a minimum of once a week. I fertilize weakly when I flush. About once during the middle of that week, I use plain RO water, no fertilizer, and flush smaller pots. Large pots (half gallon size or bigger) I only fill a couple of inches past the reservoir line.

The size of the pot, and the type of orchid you're putting in the pot, also dictates how much reservoir you have. Perhaps you don't have enough reservoir for some of them? I don't know, just asking.

Also, in lower humidity, there are ways to decrease evaporation. Using plastic over a portion of the top, covering top of LECA with non-porous stones (rocks) or marbles, or decorative glass stones.

That is what I want too, except a few older plants I doubt they could be converted.

With plastic containers two holes are no problem but I'm much to lazy drilling holes into glass. So I'll stick with one hole in my glass containers :biggrin:

Very good information and tips, thank you so much.
I'll definitely try rocks above the LECA and a similar method to flush as you described.
Time will tell, thanks again.

i assume you are asking about the need to flush, but the advantage of the SH method is you CAN flush all the time and the more water, the more action (growth)

i flush (rain water) almost all my SH plants every day and i fertilize daily with super dilute K-Lite

You are right DC, I wanted to know how often I HAVE to flush at least, at a minimum. Until now I have done that once a week and between refilled when it's went to get dry. The refill is always with fertilizer. Cause i can't get K-Lite here in Germany I'm using Rain Mix which is rather similar. Every two weeks I add Kelpak (same as KelpMax) to the solution.

And DC, I’m not convinced flushing daily makes them grow quicker. What’s your rationale for that?