Folks who live in-, and grow their orchids in a very dry environment often have issues with extremely fast evaporation of water from the top-most parts of the LECA growing medium, and the resultant relatively fast buildup of mineral and waste products. While frequent watering and flushing may be one way to remedy that, many find that an evaporation reducing barrier, placed on top of the pot, may be a big help. A sheet of clear, flexible plastic film, and a pair of scissors is all you need.
► Cut a circular disk of the plastic that is approximately one inch smaller in diameter than the interior of the pot. Choose a plastic that has more rigidity than food wrap – I have often cut up plastic page sleeves purchased at an office supplies store.
► Cut a slit from the perimeter to the center of the disk.
► Cut out another hole in the center that will accommodate the base of the plant, again making it about one inch larger in diameter. The end result should look something like this:
► Separate the cut ends of the plastic disk and carefully place it around the base of the plant, and you’re all done!
As the water evaporates from the pot, a good deal of it will condense on the film and drip back into the pot, keeping it more uniformly moist, top-to-bottom.
There is no need to remove it for watering, just flood the pot, filling it rapidly to the top as you should always do, with the water entering around the plant base, and the perimeter of the pot.