I did some searching on the web last night and have come to the conclusion that I am doing a couple of things wrong with my watering. First, I may be using too much fertilizer. I have wondered about the white “stuff” on my orchid roots where they appear above the LECA pellets. Now I believe that this is a salt buildup. Second, I have not been flushing my pots with clean water, and this is allowing the salts to buildup in my pots, harming the roots of the plants, and (perhaps) killing a few. I am going to do four things…
- I am going to use only a teaspoon of fertilizer per five gallons of water. This should reduce the salts going into my plants. In calculating the amount of fertilizer, I believe that I should have noted that I am watering twice per week. If I take this into consideration, my “weakly weekly” fertilizing was too strong by a factor of two.
- I am going to incorporate a watering schedule of one watering with clear water, one watering with MSU+Kelpmax, and two waterings of MSU. This should get clear water through my plants twice a month. Recommendations for Kelpmax state that one should use it about every fourth watering in general, four straight waterings for new plants, and four straight waterings in the spring to give the plants a jump start. This should not be too different if I use half the recommended dose per watering.
- I have ordered a bottle of General Hydroponics FloraKleen QT, a solution that you can use with your plants to clean out the excess salts from your medium. This is probably a once-a-month preventive solution – although I will read the label, of course.
- I will also take out and replace the “salty” pellets from my pots. This is recommended by Ray Barkalow in several posts.
I will watch the plants over the next few months, and see what happens. In about a month, many of my plants will go into their winter rest period, and that will mean clean water only.