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       Solar Hydroponics
       June 24th, 2018
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       I'm doing some mental planning toward a very small hydroponics
       experiment. I will likely start with just one plant, an herb, in
       a solo environment. I know I can do a self-contained system
       without aeration at that scale, but I want to build it as if it
       were a larger system, but in miniature. I want the system to be
       off-grid as well. I'd like it to be as mechanical as possible, in
       fact.
       
       I found one little video oh a solar radiation powered aerator.
       Basically, it was an empty air chamber that was darkly colored and
       had no-return valves that forced air in one hole only and out
       through the "pump". The out-bound port was covered in a bubbler
       rock. When the sun hit the bottle it heated the air inside, which
       forced the air forward out into the reservoir. When the bottle
       cooled it would draw more air back in through the outer valve. If
       the sun cycled exposure at a fairly regular interval, it seems
       like it might help circulate some into the reservoir over time.
       
       There were lots of problems with it, of course. The pressure of
       the temperature change didn't create that much air flow. If the
       light were fairly constant it would only expel once and then be at
       rest. It needs some work to draw and billow more air. I was
       thinking about having a radiometer inside the chamber, as air flow
       inside would force it to work as a more continuous air pump, but
       I think those barely create enough force to spin in a vacuum. I'm
       close to a solve here that does not involve electronics at all,
       but I'm just not quite there.
       
       Once that's fixed, my next line of inquiry will be nutrients. What
       exactly goes into those fertilizer bits and how can I generate my
       own source without a store. Is that even a reasonable thing to do?
       
       If I can solve for solar powered aeration (not using solar panels
       & electronics) and nutrient creation, then I should be able to
       construct a fully off-grid, automated hydroponics rig. I am just
       awful at remembering to do things on a regular basis, so if this
       is to succeed I absolutely must automate.
       
       Other things to consider:
       
       - Auto-balancing water distribution to the correct levels
       - Rotation / cycling position for sun exposure
       - Portability of net systems for transferring between small
         & larger rigs
       - Auto-timing of nutrient injection & mixing
       
       Do any of you have experience in hydroponics? Anything to add?