solarcene_community_setup/hydroponics

Garage Hydroponics

Aim/Reason

Due to the nature of a solar powered system there is lots of sun in the summer and not much sun in the winter, I've focused on building a setup that manages to run all winter and this has resulted in 'overspeccing' the solar panels and squeezing the efficiency of the system. It meant that in the summer there was excess solar power just going to waste. I thought about various ways we could use it up such as run more devices/services but it felt that this wasn't a positive use. Instead I thought we could use the excess power to run hydroponic grow lights and reap the benefits (literally).

Successful setup

The whole process was a bit of an experiment and after a big fail of a start and some upgrades I did manage to grow a number of basil plants and their harvest resulted in fresh basil for cooking and at the end of the season we made pesto and coupled with our home grown (outside) tomatoes and onions had a lovely meal of make your own bruscheta (we didn't make the bread, hummous or mozzarella - apologies).

The approach that worked was to use the Kratky method of Hydroponics:

• 1 large container, 6 holes drilled into the lid
• 6 3d printed Netcups
• Rock wool starter medium with some clay balls to fill in gaps
• 3 basil seeds per starter (which were thinned down to 1)
• Buddha Tree Organicus feed (from PremierGrow)
• 2 * 12V 72 LED strips (+ a 2 strips of red/blue leds but i'm not sure they contributed much) - (from https://amzn.eu/d/9K7ShHZ but I now try not to buy from Amzon)
• 18V Fan (running at 12V) from the junk box, wired alongside the lights
• 12v Relay controlled by 'dietpi' - I varied how long I would have the lights on for but usually about 12-14hrs, often starting a little later in the day so that I wasn't drawing lots of power from the battery before the solar panels had started to work.
• 5V 10W USB Water Heater, set to 18C (from https://amzn.eu/d/8pRSIyF)

Challenges

• The garage room that I have my equipment in gets cold in the winter and remains cold for a long while - it was therefore necessary to add the water heater to keep the system working in the spring months but this added more power draw for the solar system which wasn't ideal. I've since insulated the garage and so hopefully this will make it a little easier to keep at least a reasonable temperature.
• The pH monitor I purchased wasn't great quality and I'm also not very careful with accuracy so I suspect that the pH wasn't ideal - I might well invest in better pH monitoring device and hopefully this will make it easier.
• I probably need to be a bit more aggressive with harvesting the basil as it got a bit 'leggy' near the end - I understand that due to the close proximity to the lights compared to the sun this can result in slightly different growth rates.
• Weird looks - luckily my family are used to my experiements but the concept was a bit weird and when I spoke about it got some dodgy looks!
• Its not possible to run the hydroponics all year, I mean I could just grow the basil outside...

Next Steps

Keen to do this again with some lessons learnt:

• Temperature Control - I'll have the water heater from the beginning, hopefully with the insulation of the room coupled with additional insulation around the hydroponics and the water heater we'll be able to generate a nice warm growing environment.
• Better pH control, this was definitely and issue last year, I may invest in a better device to track the pH
• Stick with basil - it fitted into our meals easily
• Better monitoring - perhaps a camera...
• This year I'm going to stick with the Kratky method but in future I would be tempted to try different methods of hydroponic growing.

Images

Early failed attempts

The initial attempt was just too ambitious, after watching a load of youtube videos I attempted to grow 2 containers and with only 1 light strip per container. Also attempted to grow bok choi. It quickly became apparent that there wasn't enough light per plant and so I consolidated the lights to 2 strips for a single container.