Backyard Aquaponics
A place to discuss aquaponics

Howdy all! I have an outdoor koi system, and an indoor tropical system. However, I want to plan for a future (very large) system that is not only rugged, but requires the least amount of external input after initial setup. I'm hoping to network with other people with similar interest so that we can bank off each others ideas.

My thoughts so far:

Energy and Power
Solar will be the primary energy source. With a massive battery bank, the system should run flawlessly through stormy/cloudy days. In central Texas, our whole winter is just about overcast. To conserve energy, a micro-controller can be programed to run the system on a "power save" mode during these overcast days. This would mean less-frequent growbed floods and less feeding of the fish. Any thoughts on backup sources of energy in the central Texas area? Perhaps a wood burning system as a last-resort backup, these could also be useful in the winter (when you would need it most) because excess heat can be used to warm the tanks.
Heating and Cooling
Modern heating and cooling techniques are very energy intensive. I figure heating and cooling can be accomplished with geo-thermal (well, not much heating, but 60F (15C) degree ground water feels warm when it's 25F (-3C) degrees above ground). Maybe the majority of heating can be conducted with a solar water heater. The tank will be submerged in the ground to reduce drastic heat gain and loss. Hopefully I will find that if the tank is large enough and berried deep enough, I wont need much heating and cooling. After all, tilapia live in just a few feet (< 1 meter) of water in Houston bayous, and rainbow trout live year round in the Guadalupe river.
Fish Selection
I use to have bass, crappie, catfish, and various perch/sunfish (never on an large scale). All seem to be good choices for central Texas. I've had rainbow and golden trout, but they are kind of high maintenance. They are also jumpers and my cats would eat them if I couldn't save them in time. So rule trout out of the question. Something I have never had is tilapia, and I want to try them out. I realize they require lots of heat in the winter, but once again, I think with an underground/submerged tank, they may live just fine with minimal input. There are more things I need to think about and consider in the fish selection department, like food inputs and ease of breeding. I have also though about having multiple tanks to have multiple fish species.
Fish Inputs - Food
This is my driving consideration in fish selection. Obviously fish food is hard to come by if you want to eliminate external inputs. I don't think there is a sure-fire way to avoid it, fish food will have to be bought, but I will focus on minimizing the amount of food needed. Black soldier flies are so easy and free to grow off of waste products. I grow them for our chickens off of kitchen scraps and I feed them to the koi too. My only concern is pathogens being introduced if the BSFL larva are grown on manure (like chicken poop). They say that an active BSFL colony will kill pathogens though. Growing minnows is an option because they breed like crazy. If tossed food scraps, a tank of marbled crawfish will clone thousands of crawdads. I know the 3 mentioned foods will be loved by bass, crappie, perch, and catfish. I don't know about tilapia. I also don't know much about growing duckweed, but people say it's easy. There is no such thing as perpetual motion... you can't grow food for the fish off your AP system (but some can be recycled, obvisouly). However, using minnows, BSFL larva, and crawdads allows you to convert cheap external inputs into fish food. Thoughts, comments, ideas, are needed in this realm.
Plant Selection
The use of a greenhouse can allow for an extended growing season of summer crops. Other than that, growing crops only in-season is probably the cheapest way.... no need to heat your tomatoes in the winter and cool your lettuce in the summer.
Pumps and Stuff
There are so many ways to cut corners and make the typical AP system more efficient. For instance, why pump water twice for a flood cycle? Burying the tank in the ground will cut the need for a sump pump. Aligning the growbeds to the height of the fish tank will reduce the load on the pump by lowering the head. Switching over to DC pumps will also increase the efficiently-- they require less electricity per work performed, and since the system is solar powered, you won't have the loss from a DC=>AC transformer.
Other Stuff
Rainwater is kind of a no-brainer... You don't have to worry about the crap in tap water. I'm a big fan of ground water (good minerals, etc), but depending where you live, the PH from limestone might make the water unsuitable for fish. I've measured my tap water to be a PH of 10!


All thoughts and ideas are appreciated! (even constructive ones)

Welcome to the fun Concealed!

My only thoughts are that a greenhouse should only be intended to extend the growing of plants and animals that can live in your climate natively. The other is that high capital costs could be more than running costs, like to buy solar panels and finance them could easily negate any gains from avoiding the running costs of grid electricity. If possible you could instead select a plan from the power company that uses renewables (we had this option for a time with our power company but it's been dropped for some reason). Also I imagine that reducing the inputs to minimum will also reduce productivity of the system comparatively. Good luck!!

Your right about startup costs. The solar/battery/controller setup might cost more than the AP system itself. I have a solution for that if it is a problem... you build the system now with the components you would use for a solar-powered system and run it ON the grid with an AC DC transformer. This way you can drop in a solar-system later.. giving you time to save up cash, shop around for a sweet deal, or get the stuff free (people throw out good stuff all the time, those that keep an eye out are often rewarded with good free stuff).

You can buy so called clean energy, but unfortunately that is not the point I'm getting at here. I'm trying to foster an idea of self-reliance.... and in effect creating sustainability. I've had plenty of times where the power was out for a week or more, a solar powered system will definitely be beneficial here.

Thanks for the thoughts Dave!

Lots of stuff here.
1: If it's cloudy during the winter I don't think solar hot water heating will work that well.
2: The point of the a CHIFT PIST system is well... read up on it. (you will want the ST)
3: I haven't read any good things about DC pumps (water or air) on the forum. DC loses power via transmission more readily than AC.

It's been said, "efficiency is the straightest path to hell." See the 2nd to last page of my 20 gallon starter system.

creating a whole fish based ecosystem would kind of be like having a pond, where you'd create an algea bloom, add your minnows to get established (provide breeding structure), then add game fish.. there's an art to balancing a "diverse" fish population, and the "ponds" that produce big fish supplement with high quality feed
given the room, i would think a good approach would be to limit the number of fish that would have a wider demand on the system..concentrate on specific breed to narrow the support parameters...
i don't think i'm expressing what i mean very well here, i better go have a beer

With regards to DC pumps, I think you will struggle to find good efficient DC pumps that will move the same amount of water as AC pumps. AC pumps are more commonly used, hence companies are driven to make more energy efficient (via design of pump components, etc) AC pumps compared to DC pumps.

Also to provide the same amount of energy as an AC pump, an DC pump will require more current, more current will equal more heat lost. Heat is the worst "enemy" for any energy conversion as it is wasted energy.

Furthermore, battery suitable for solar power are very expensive and will require replacement after a number of years of operation... hence you are looking spending more money again in about 10 year (I think that is the life of solar batteries)...

If it's supposed to be "Ultra sustainable" then you have to go lower tech for many aspects, high tech is rarely the answer to sustainability. Look into green water cultures perhaps and growing plants in and on the same water the fish are in, then little to no pumping is required.

Have you tried running a smaller AP system to give you a taste of how everything runs.

It is important to look at what you are doing every day already and see how you can modify that to help sustain your aquaponic setup.
Are your fish omnivorous? Then veggie scraps that come from the market or the table can go into the fishtank. If not, then compost to raise worms for food.
Collect compost from your yard, and neighbors if you trust that they don't spray stuff, also to raise worms for food. Some folks, if fortunate in their location or their friends, use wine or beer brewing leftovers as compost.
Can you plumb a hose through to house for heating and cooling? Might help enough that you don't need a separate heater or cooler for the fishtank.
Fish tank outdoors? Hang a light or bug zapper over it at night to attract bugs to fall into the tank.
Scraps from the butcher or roadside can feed fly maggots. Not my cup of tea, but has been done. etc etc
No one thing will make a huge difference, but lots of little things will.

I guess it depends on what your goal of the ultra sustainability is. If you are out to be "super green" is one thing. If you are looking to be more self-relient, that is another thing. As others have mentioned, doing a lot of little things around the house is an easier way to go green. If, like me, your focus is more preparedness type sustainability, then that is a whole different game with different parameters.

Thanks everyone for all the great replies! Keep em comin'.

I will point out for the record I am more interested in the self-reliant (preparedness) part. There's been many times in my life where I've been weeks without power because of outages. This is why I want to build my next system to withstand such abuse without a flinch.

cjinVT: Thanks, I've been looking up CHIFT PIST systems lately. I can't say that I understand the advantages for a large aquaponics system though. However, the next small system I am working on is going to have a pump only in the sump purely for aesthetics. You're right on the hot water heater, when it's actually cold around here, it's almost always cloudy! I'll have to consult with some solar water heater users around here to judge effectiveness.
keith: Thanks, I've given thought to building a large pond that would be a little closer to sustaining itselve than a fish tank. I've seen people that build black soldier fly bins over the water so when the grubs mature and crawl out, they are instantly eaten by the sharks swirling under
ivansng: Are you sure about AC being more efficient? There are a lot of industrial applications using DC (typically 24-48 volt). I will have to do more research, but I have talked to one engineer about the issue at hand. I also received used batteries as a gift... so I've got that problem out of the way. Yes you're right, the overall lifetime of deep cycle batteries is a bit of a turn off, however buying used/cheap will definitely pay for it's self over time.... specially if the power goes out and they save all your fish.
earthbound: cool, thanks.
Dufflight: I've got 2, one medium and one small.
bwaite: good suggestions. I do want the system to run on it's own though... I want to ditch my house in favor of becoming a vagabond I do grow fly maggots (black soldier flies). If you have never tried it, it's probably a lot easier than you think.... and extremely productive (high grub-weight vs scraps ratio).
DéjàVoodoo: definitely preparedness. Unfortunately, greenies are typically counter-productive in their search for a eco-sensitive lifestyle. I'm for a clean earth, clean environment, and clean food. I've studied how they do it in Italy, and I want to replicate their system here.

Case and point on the self-reliance bit. We're experiencing rolling blackouts today and both my systems are currently offline.

I've seen smaller (around 50 gallon) aquariums that were wound up each day like clocks, or had pulleys and counterweights that ran the air pumps. With a little creativity (and a firm grasp of physics) I'm sure a larger system could be set up like that to be people-powered. It would just have to be reset every day. But if designed right, you could add a stationary bike into the works and wind up the system as part of your morning workout :p

Indeed a fun topic:

viewtopic.php?f=1&t=2092&st=0&sk=t&sd=a

I live in Sugar Land (near Houston) and am wondering what kind of fish to run. I am considering Tilapia, since apparently they can be fed grass clippings, duckweed, BSF, and other stuff. Sounds interesting. I could probably grow duckweed and minnows in a kiddy pool on the side of my house. I'll probably grow that in my rain barrel too.

I have two solar water heater panels that I bought used in Austin about 7 or 8 years ago. they have just been stored leaning against my house. I think that I will mount them near the tank, and use a small pump on a separate circuit. It can be a fairly small pump and I'll run it only when I think that the heating will be benneficial to the system. Probably 3 seasons a year, if the tilapia like the water hotter. One odd item is that the energy consumed by the pump will heat the water too, not much different from an electric heater if I tossed one in. Not that I will do that, as it will be too expensive to heat electrically.

I did look for DC pumps for my saltwater aquarium as a back up that could be run from a battery. There look to be VERY few, for whatever reason.