raybark Site Admin

Joined: 04 Mar 2008 Posts: 143
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Posted: Fri Jun 26, 2009 7:55 am Post subject: Mineral Buildup in Media |
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ALL brands of LECA, just like other media components, will build up minerals with time, so that may affect your thinking about frequency of repotting.
How rapidly they do so will be affected by the porosity of the pellet - both size and distribution within the particle - how thoroughly you flush the pots with each watering, and your growing conditions.
[A bit of a plug here: PrimeAgra is specifically designed to release what it absorbs to a great degree, so is probably the least prone to build up minerals of all inert media components.] As there is nothing you can do about the medium once you've purchased it, it's the other two you can control.
If you flush heavily when you fertigate your plants, you obviously do a better job of "cleaning" the medium than if you water minimally, and if you water more frequently, you reduce the time for buildup to occur.
Maintaining high humidity is not only good for your plants, it helps reduce buildup as well.
Just like the wicking from pellet to pellet, the absorption and release of nutrient solution takes time. In a humid environment, the absorbed material remains a liquid throughout the pellet, so as it leaves, the concentration of minerals stays relatively uniform throughout, including as it is taken up by the plant, diluting the solution.
In a dry environment however, the solution at the surface tends to evaporate at a faster rate than the solution can move from the interior of the pellet. As that happens, the solution at the surface gets more concentrated, which forces the interior concentration to increase, and with more and more evaporation, the solids drop out of solution and can clog the pores altogether. _________________ Ray Barkalow
Orchid Iconoclast |
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