Semi hydro help

[JimNJ]

I’m trying a few plants on semi-hydro, hoping to rejuvenate them - after 2 weeks, I noticed white precipitate forming on the topmost Leca balls. I noticed new roots starting to grow so the plant seems to be adapting, but wanted to get feedback on what’s happening and what I should be doing differently. I’m watering with 1/8th tsp/gallon MSU K-lite with each watering, letting it flow out of the side holes, put in a half inch or so from the bottom. Are the salts accumulating in the topmost layer as liquid is pulled up as it’s evaporating in just 2 weeks? Thanks!

 

[Ray]

Are you rapidly filling the container to the top and then letting it drain, ir just trickling the water in? The first does a better flushing job.

Assuming you're flushing with each watering, it might be from inadequate LECA preparation.

There are binders added to the clay to get it to stick together when unfired. They may-, or may not be completely removed during firing. If the pellets are not soaked long enough before use, those salts may evolve over the first 6-8 weeks of use.

Also...if the environment is such that the top surface dries between waterings, you'll always get more rapid buildup than if it stays moist.