Fish Don’t Fart

Portable Farms founder Colle Davis

Earlier this week we posted about home-scaled fish farming coming to a Home Depot near you. Yesterday we came across mention of another aquaponics supplier, Portable Farms ( that produces larger greenhouse-based cultivation/aquaponics setups ranging in size from 6′ x 8′ to 90′ x 120′. The greenhouse seems like a good idea since, even in our warm Southern California climate, common aquaponics fish such as tilapia need heated water. Portable Farms owner Colle Davis runs a two acre farm in Escondido California and has been working on his aquaponics system for over 37 years. The tag line “Fish Don’t Fart” refers to the benefits of fish over methane generating cattle.

We skipped over aquaponics in our book since we considered it too expensive and complicated for most people. But perhaps we should give it closer consideration. Aquaponics is profiled in the pioneering urban homesteading book, The Integral Urban House: Self Reliant Living in the Cityand Scott Kellogg and Stacy Pettigrew’s book Toolbox for Sustainable City Living: A do-it-Ourselves Guidewhich comes out of their work at Austin’s Rhizome Collective. What all of these efforts have in common is a permacultural design principle of turning a waste product into a resource and closing a loop. Fish make fertilizer and plants clean water, so why not combine the two?

I’d like to hear stories from ordinary folks who have tried aquaponics on a small scale. If that’s you, leave a comment!

Leave a comment


  1. Wow, what a great tagline. I wonder how many people who hear it will “get it” the first time around.

    I’ve thus far resisted the hydroponic concept because first of all as you say it always seemed far too expensive, and secondly, the quality of hydroponic vegetables never impressed me. I think stand alone hydroponic is simply too far from a “real” ecosystem, with all kinds of stuff going on in the soil, and the normal challenges of wind, temperature variation, pests, etc.

    Humans aren’t yet smart enough to supply everything in a closed system that a plant needs to thrive, in my opinion. And hasn’t it been found that many of the phytochemicals in plants are produced to deter pests and disease? Still, aquaponics certainly seems like a step in the right direction. I look forward to hearing more about it.

  2. I did my first aquaponics experiment when I was 8. I suspended a pothos cutting in the fish tank. It rooted faster than the ones my mom was doing in tap water. Little did I know I would fall in love with hydroponics and aquaponics. Thanks for the heads up on the literature.


    A lot of the bunch tomatoes at the grocery store are already grown hydroponically. They use less fertilizer and water than traditional field grown crops and often need less pesticide. How is that not an advantage over or as “complete an ecosystem” as traditional farming?

  3. some classmates of mine used an old plastic recycle bin, put two long rectangular pots on top of the trash can, and a simple home depot pump to circulate the water through drip tubing. probably didn’t cost more than 35 bucks. And they did another with a hand watering system Here’s a link to their study.
    I watched it and maintained it over a summer, it seemed to work fine, they needed to work on their drip irrigation skills. but besides that it was fine.

  4. Red sed: “A lot of the bunch tomatoes at the grocery store are already grown hydroponically. They use less fertilizer and water than traditional field grown crops and often need less pesticide. How is that not an advantage over or as “complete an ecosystem” as traditional farming?”

    I don’t mean to be argumentative or surly, but the tomatoes at the grocery store are precisely what I had in mind when I said that hydroponically raised vegetables don’t impress me. I stopped buying fresh tomatoes (other than at farmer’s markets) about 10 years ago. Now I just grow my own, and even those aren’t worth the name of tomato, in my opinion, other than for two weeks out of the year, three if we have a good year.

    As for hydroponics being more advantageous than “traditional” farming, I suppose it depends on what you mean by “traditional.” If you’re referring to what has fairly recently become the standard, i.e. industrial farming, then I would agree that hydroponics offers some advantages in that it needs fewer pesticides and does less damage to the environment. But if you compare it to organic IPM, or permaculture, or just plain old backyard gardening with no chemicals, then on the whole I would say it is not an advantage, when you compare the costs and yields of these systems. Hydroponics, so far as I understand, offers nothing to beneficial insects, birds, fungus, or plants external to the system. It is an artificial closed system, built and maintained at high costs of energy and labor, designed to benefit humans alone. That just doesn’t seem sustainable to me.

    No offense. Just explaining my views, since you asked.

  5. I just saw some mini-aquaponics systems at by local nursery, which seem to by a tilapia fish tank that’s used to grow a few extra plants. Since I’m more interested in the fish, it looked perfect.
    Now I just need to find a system that allows for growing salmon. Maybe in an endless swimming pool…

  6. Now where does one get tilapia fingerlings in lots of less than 1000? I’m almost ready to go with a 225 gal. tank in my greenhouse, but I need fishies!

  7. check a vietnamese market. Forgot to mention, we kept the bin with the tilapia in the sun. It heats up pretty nicely and didn’t need any extra heat sources. (i think fish don’t burp would be more accurate, but it’s not as funny as fish don’t fart)

  8. Does anybody know if it’s feasible to farm with local varieties of fish, like bluegill, crappy, or catfish? They don’t have the same temperature requirements that Tilapia have.

  9. Be careful with Colle Davis. My experience with him was pretty sour. He is only interested in the green of the money, not the green of the veggies. They refuse to sell you a kit, they force you to buy through one of their dealers and you must pay them to install it. Check out the hydroponic sites down in Australia. These guys are way more advanced than Colle Davis and they won’t charge you for advice.

  10. Verona, that might be an interesting study for a graduate student in regenerative studies. I do know however that the Arroyo chub is just as effective as mosquito fish for vector control. It is a native but it cannot compete with the mosquito fish.

  11. Growing Power in Milwaukee has developed/implemented the fish/veggie system, using the principles suggested in the article – the fish waste is used by the plants who clean the water to be used again by the fish.

  12. Verona,
    The reason that Tilapia is the preferred fish for aquaculture is that they can tolerate greater stocking densities than other fish and I think they can deal with lower dissolved oxygen in the water too. The second best species I’ve investigated is catfish. Search the Mother Earth News archives, I know they have had a few articles on this.

  13. *sigh* I’m sorry I missed this post earlier.

    Verona, it is certainly possible to do aquaponics with catfish, bluegill and other native fish.

    If you want to get into home aquaponics, these are the best resources:
    A system built out of blue barrels, and can be built for almost free if you’re a good scrounger:
    and see the “barrelponics” manual at

    Also, the forums at are an amazing resource.

    My systems:

  14. This is on my list of projects. I live in Hawaii where we have something called rat lung disease. The prevalence of this makes growing greens in the ground less than ideal. With aquaponics, I’d be able to keep the greens out of reach of the slugs. I’ve seen a very small aquaponics setup that would be sufficient for keeping my family of four in salad greens with very little cash outlay.

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