Backyard Aquaponics – The Solar Power and the Pumps

Ive introduced my aquaponics project, talked about the magic of the bell siphon, and discussed my containers and what is in them.

Now I want to go over the power system, the pumps, and moving forward.

I’ve wanted to establish a 12v solar charging system for years, since I live so far south and have all of this free sunshine going to waste. (I’ve often wondered why no one has come out with a production model of an a/c unit that is solar powered – The the more sun you have, the more you need a/c, it just seems like a no-brainer product to me…)

48 watt M75 solar panel
Specs on my First Solar Panel

I have plenty of low voltage gadgets: phones, Kindles, flashlights, lanterns, two-way radios, etc. I wanted a way to charge them, should we ever have a power failure like we did during hurricanes Jeanne and Frances. It would save wasting gas on the generators, and would always be available for other things like lighting and fans for my poultry and rabbits, as well as spare 12v batteries that are always topped off for trolling motors, or emergency car battery replacements.

So when I ran across an add for a 48watt solar panel on Craigslist for $100, I jumped on it. I then traded for a 12v deep cycle marine battery, and was in business.

Or so I thought.

Researching the best way to charge a 12v deep cycle battery, I found a charge controller makes it a far more efficient, and less dangerous, process. Crud. More expenses. I found a 10 amp entry level model for $12…SWEET! I was thinking it was going to cost hundreds for something called a “solar charge controller”.

The setup is straightforward – panel to controller, controller to battery. All draw runs thorough the controller to make sure the power delivered is “clean”, and allows the controller to shut off the draw if the batteries get too low. Simple!

Until I realized my meager draw was eating my batteries faster than they were being charged.

Sopray SR-50 Solar panel specs
Specs on my second solar panel

So I purchased another panel, a Sopray SR-50 50watt, cost was actually less than the first one, on sale at $99 delivered. This panel received great reviews, and would work well with my existing setup. However, I now needed a larger charge controller to handle the extra output, so I opted for the 1224-20a 12v/24v 20a Pwm Solar Charge Controller, a nice upgrade that should keep me going for at least another solar panel, should I ever chose to add one.

This setup now produced FAR more power than I could store on a single battery, so I was wasting juice I was already harvesting! ACK! So I traded for another deep cycle battery, and hooked it in parallel with the first.

I now have almost 90watts of solar power charging two deep cycle batteries that total about 120 amp hours of stored energy. This has been great for all my 12v needs. Mostly. I’m thinking about adding another battery, if I can barter for one. And maybe another panel…

This is the joy of this system,  the ability to add components as you need (or can afford) them. Need more storage? Add another battery. Need more output? Grab another panel! Expand as your needs grow.

As I said before, I’m using it currently (eyeroll!) to power a 12v light for my quail to give them more light, increasing my egg production. I’m also using it to power a fan for cooling off the rabbits in the summer.



As to those stupid pumps for my aquaponics system….

I started using a 12v bilge pump I had left over from my boating says. It was great for about 2 weeks, running 24 hours a day. It died, and I was unable to resurrect it. Thinking it was a fluke, I bought another one. Same end result.

I called a couple plumbers I knew and they all said the same thing, that a 12v pump that was rated to run continuously would cost me hundreds of dollars. Pass. The other options was to go with a 110v system, like most of the appliances in our houses use.

I tried an inverter I had stashed away for camping, and dug out an old 110 fountain ump, and I was back in business. Not ideal, going from 12v to 110, but for now, it works. This has been the only real issue I’ve had that I’ve not found a satisfactory answer.

Any ideas out there? I’d love to hear of a reliable continuous pump that is powered on 12v. Let me know!


Conclusion and Moving Forward

Like most things in life, nothing is static. As my needs grow or change, so will the answers to resolving the issues those changes pose. I would love to get a larger container and expand my growing capabilities. It probably won’t happen while we live here in town, we are simply too short on space as it is.

For now, I’m going to call the aquaponics project a successful one, if only as a learning experience. The knowledge I’ve gained as I put each piece into operation will be added to my bag of tricks. The solar portion I will definitely expand on, even if I stop with the aquaponics. For less than $300, I now have an large amount of free 12v power I can apply towards other projects around the Urbanstead. It will be nice to know that I have alternatives to power things if times get harder than they already are…

….just in case.



    1. Three times as powerful, and costs less. The HF solar setup is three 15 watt panels, the controller, and I believe a light fixture, priced at $250-ish, $150 on sale.

      The panel I final ended up getting was about $100 for a 50 watt panel, but now mounting hardware and no controller. I see the price has increased a bit from when I bought it, but even at $170, I’d still call it a better option.

    1. More than enough….but every 12v pump I’ve tried died after a few weeks. I have lots of power to spare compared to what I use daily.

      I’ve recently gone to a 110 200 watt inverter with a plug in lamp timer and a submersible 110 pup. This seems to be working great now. It’s been a couple month with no pump death. Yay!

  1. Ok, good to know. I’m working on designing a small system for my balcony, but everyone is talking about outlet-powered pumps while I’m really interesting in solar. Submersibles seem to be more reliable and have overall less draw, from what I read.

    Were you going with the bilge pumps because you didn’t want to use an inverter?

    1. I tried using the 12v submersible bilge pumps with a 2 year guarantee, but burnt through them. Opting to use a submersible fountain pump, even with the 110 conversion, definitely works better.

      Best of luck to you on your endeavors! Solar is fun…and the electricity is free (once you are set up :P)

  2. Try using a water transfer pump from tractor supply. They are able to be rebuilt and use 3\4″ water hose fittings. Run off of 12 volt dc. We use them for fuel transfer and pumping water out of tanks.

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