Aquaponics update

Discussion in 'Homesteading Questions' started by cowboy joe, May 4, 2006.

  1. cowboy joe

    cowboy joe Hired Hand

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    Well, it finally happened. After a long winter of research, construction, and hard work, my aquaponics system, albeit small, has come to life. The fish have made it through the first few weeks in the tank and have given ‘birth’ to a pair of tomato seedlings.

    The fish tank is an old 100 gallon Rubbermaid stock tank now buried up to the rim in the greenhouse. The tank is not only a home for the fish & the food source for the hydroponic system, but also provides thermal storage and humidification for the greenhouse. Thermal storage is important in my neck of the woods with the long, cold winters so ‘recycled’ foam padding was added to insulate the outside of the tank before the unit was lowered into the ground.

    The hydroponic portion of the system is modeled after a small, PVC unit which I read about on-line:

    http://www.hydroponicsonline.com/11plan01.htm

    The construction of the system was fairly straight forward and the PVC hydroponics fixture went together in a few hours. The PVC frame sits over the tank with plenty of room for another system or two if I decide to expand in the future. The stacked setup allows easy access to the tank and the grow beds while making best use of the limited space in the 12x8 greenhouse.

    BTW…the pump cost me $5 from Harbor Freight and runs on less average energy than my night light…er, if I used a night light that is…not like I’m afraid of the dark or anything. Unfortunately the pump runs on AC so I’m working on an inverter so the system can be run off of a small solar panel that is already installed for the greenhouse. I’m also building an electronic timer as the mechanical timers run for a minimum of 15 minutes which is unnecessary considering the cups fill in less than 2 minutes. Feeding costs are basically zero as the fish receive a daily ration of worms from a vermiculture system I stated this spring.

    Balancing the system was a real brain teaser…a veritable real catch 22…the fish will die if there aren’t any plants to remove the toxins from the water and the plants won’t grow if there aren’t any nutrients from the fish waste. I opted to start slow with 8, ~3-5” brown bullhead in the tank and seeds in the hydroponic fixture. I figured the tank was big enough to support the small number of fish without building up too much waste until the bacteria in the gravel beds and the plants become established. It seems to be working but there are still plenty of opportunities for something to go wrong. Any old who, I’ll take this as a small victory…for the fish & plants anyway. The cat is put out as she was banished from the greenhouse shortly after her first fishing expedition and the ‘garden weasel’, aka Stitch the ferret, visits only during supervised work detail when he is allowed to cultivate empty soil beds. What I can I say…it’s a work in progress.
     
  2. wy_white_wolf

    wy_white_wolf Just howling at the moon

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    Sounds COOL!

    Pictures PLEASE!

    Will diffinately look forward to updates as to how it's working for you
     

  3. moldy

    moldy Well-Known Member

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    Will be watching this thread; interesting ideas!
     
  4. Arklady

    Arklady Well-Known Member

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    Hey what kind of fish are those and where did you get them???

    I have a spare heavy pond for a garden I was thinking I could use. It's one of those kind that you are supposed make pretty but it is not practical where I am now because of my geese but in a green house it would be perfect.

    Now I want to see pics and what plants are you putting in the cups?

    This is very cool...

    Arklady :)
     
  5. cowboy joe

    cowboy joe Hired Hand

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    The fish are bullhead (think small catfish). I caught them in a local pond...they weren't big enough for dinner but since they are very tolerant of less than ideal conditions I thought that they would be perfect for the tank...they taste good too.

    Thanks for the words of encouragement :cowboy:. I'll post some picture if I can.
     
  6. Hurricane Kurt

    Hurricane Kurt Well-Known Member

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    Thanks for posting the update. Auquaponics was one of my favorite things to read about over the winter. Look forward to some pictures of your buried setup.

    Kurt
     
  7. cowboy joe

    cowboy joe Hired Hand

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    I promised an update and some pictures on my aquaponics system. Hope I posted these pictures correctly:

    http://www1.snapfish.com/slideshow/...ID=1240739802/a=14069951_14069951/t_=14069951

    http://www1.snapfish.com/slideshow/...ID=1240731959/a=14069951_14069951/t_=14069951

    http://www1.snapfish.com/slideshow/...ID=1240739803/a=14069951_14069951/t_=14069951


    The system has been up and running for about a month now. So far so good. We now have 5 tomato seedlings in the cups. All five seedlings have their first set of true leaves and are about an inch high. I started seeds from the same pack in a traditional dirt garden at the same time. We have 3 seedlings of about 1 ½ “ in height from the 11 planted (same number as the amount of cups on the hydroponic fixture).

    The fish tank went from fairly clear (I could see the bottom) to dark green last weekend even though the shade on the greenhouse was pulled down. I bit the bullet and bought a pre-made pond filter (please forgive me – I intended on constructing my own unit but was pressed for time) from Countrymax for $45 – at least it was on sale. The filter is spec’d for up to a 750 gal pond so it should have more than enough capacity to handle the 100 gal stock tank. The water is slowly starting to clear. The filter has a fountain on the top which adds a little ambience while aerating the water. The water temp is holding around 65 F despite the 90F daytime greenhouse temp. With the unit buried, the tank experiences less temperature variation and remains closer to the temperature of the ground. The tank has also increased the humidity in the greenhouse from ~20% to 35% RH…this is a real plus for the other plants and makes the area far more comfortable for me.

    I designed and prototyped a power inverter last weekend to run the pumps from a battery. The unit works but draws almost 1 ½ amps from the battery when idle and over 5 amps with the pumps running. The high idle current will undoubtedly drain the batteries…back to the drawing board. The design for the timer is complete but has yet to be prototyped. I’m having second thoughts about the design and may opt to build a computerized version to provide control & monitoring of the other greenhouse systems. I’ll probably kick myself for this later…the KISS principle et al…keep it simple stupid!

    All 8 bullhead are alive & kickin. They appear to have gained size but I can’t say how much without weighing them…I’ll leave them be rather than subject them to the unnecessary stress. They seem to like their daily ration of worms. The box is almost empty so I’ll be picking worms tonight if it rains. I’m making plans for a second box to give the worms time to breed and hopefully make the food source self sustaining.

    I’m not sure how that last picture of the garden weasel made it’s way into this post. He’s a sneaky little devil…I must admit, though, he did a nice job of cultivating the planting bed! Best wishes to all for a great day.
     
  8. Nature_Lover

    Nature_Lover Well-Known Member

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    What a cool setup!
    It sounds like you have a really well-balanced system.

    What do you test for?
    What kinds of nutrients will you have to supplement (iron, trace elements, etc.)?
    Are you gut loading the earthworms, or are they a complete diet?

    The single cell algae bloom usually occurs when there are excess phosphates in the water, and not enough waterborne plants to use it as the nitrates rise. This happens every spring in many fish ponds and water gardens (closed systems) around here, due to the farming operations' fertilizer runoff hitting the water table, and phosphorous coming out of the tap or well.
    When you physically filter it out, you reduce the phosphate to nitrogen ratio, a way to control it without reducing phosphates would be to use an ultraviolet clarifier in the pump outlet line. They are generally rated by water flow rate, not total pond volume, and depending on your pump flow, you could probably get away with a 15 watt bulb for a month or two in the spring until the hydro plants are big enough to use up the phosphates efficiently. If your pump flows too fast for a small UV to keep up with it, you can sidestream it, and just divert half of the prefiltered water through it, that's more efficient than blowing the water through the UV so fast it doesn't have a chance to kill the algae.

    Another way to reduce the likelihood of green water (and the problems it causes by using dissolved oxygen at night) would be to use hornwort or water hyacinth plants to reduce it each spring until your tomatoes are big enough to utilize the phosphates themselves. These plants compete with algae for waterborne plant foods, they don't get their nutrition from roots in soil, they filter the water for food.

    Also, you're probably aware that the algae that is trapped in your new filter will clog it and if it's an intake filter, can reduce the pump flow to the point that the water-cooled pump might overheat and ruin gaskets or melt impeller bushings. That algae can also decompose rapidly in a filter pad where it doesn't get any light, and cause a nitrite/nitrate spike, or oxygen depletion issues.

    It's sort of a catch-22 when filtering out an algae bloom, if the filter pad is too clean, it won't trap the algae, and if it's so clogged up it really filters well, it can wear out the pump or cause water quality issues.

    One other thing, the bubbles bursting at the surface will allow more oxygen to be carried in the water, they actually help the water release CO2, thereby making more room in the water for oxygen to be absorbed through the surface.
    More oxygen = faster multiplication rate for nitrosonomas and nitrobacter bacterias.

    I bet that first tomato is going to be mighty tasty!
     
  9. moopups

    moopups In Remembrance

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    Can any one provide the link to how to build the PVC system?
     
  10. Thatch

    Thatch Well-Known Member

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    He already did...

    http://www.hydroponicsonline.com/11plan01.htm


    click on the picture and it will step you through a slide show of all the supplies needed as well as how they go together. Very informative site for the small system.

    J
     
  11. cowboy joe

    cowboy joe Hired Hand

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    Wow Liz…lots of great questions and solid advice. Thanks! The system is still in the start-up phase and appears to be stable. Nothing is tested or supplemented…yet. One of the big disappointments during my research into hydroponics was the need to continuously test and balance the system with packaged ‘chemicals’…the term chemicals is used loosely here. One of the primary goals with the setup is to avoid the use of non-organic compounds. I realize the lack of true chemical balance may result in less than optimal plant growth. However, this is acceptable to me as long as the fish are healthy.

    The biggest, recognized design flaw of my system is the limited gravel available for nitrifying bacteria. The original intent was to construct an external bioreactor, a small version of the Skippy filter ( http://www.skippysstuff.com/biofiltr.htm ) to trap algae & large particles while acting as an ancillary biological breeding ground for the bacteria. The algae bloom was inevitable with the configuration due to the lack of sufficient seedling quantity / size, the southern exposure of the tank, and the optimal growing conditions in the greenhouse. I had my fingers crossed that it would hold off long enough for me to put the homemade bioreactor in place. Poor planning on my part as Mother Nature had plans of her own.

    The UV system is a great idea though I hope to avoid the need through the addition of a second hydroponics fixture. Ideally, the growth in the two fixtures will be staggered such that the overall system always has sufficient plant growth to utilize the phosphates. This will be a juggling act at best. Another primary goal was to create a system which could be maintained with minimal external energy…the addition of the large filter doesn’t help the effort yet there is still hope to limit the consumption to a level which could be supplied by a small solar energy system.

    The fish are fed controlled portions of earthworms supplemented by all the algae they care to eat. Minnows will be on the menu once the minnow trap is finished (this weekend???). Packaged food is an option but, again, one which I hope to avoid.

    Any old who…the system is a work in progress. The project started as a teaching tool to demonstrate the concepts of an ecosystem to my daughters. Obviously, Dad, that would be me, developed more grandiose plans over time. I enjoy fishing and a meal of fresh fish. Unfortunately, most of the waters in New York have advisories against eating the fish due to the level of pollutants. The revised goals includes supplementing our diet with fresh, pollutant free fish and additional fresh vegetables on a year round basis. SolarGary has an incredible website detailing some of his projects including a solar water heating system. Plans are in the works for a similar, passive method to maintain a reasonable water temperature through the winter. There I go again with the grandiose plans…
     
  12. cowboy joe

    cowboy joe Hired Hand

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    Another week has passed. The nearly triple digits hours on the job this past week have limited my time to work on the aquaponics system. There are now 6 seedlings, up 1 from last week. The original 5 have added more leaves but without gaining much size. The concern grows as the leaves are a dark green, compared to a brighter, lighter shade of their siblings which were potted in dirt.

    Thinking the lack of size & poor color were due to insufficient effluent from the fish, I stopped after work the other night and caught 4, 3” bullhead to bring the tank population to an even dozen. In retrospect, I suspect there was a phosphorous deficiency due to the algae bloom a few weeks back. Perhaps a leafy vegi such as lettuce would have been a better choice to start with as the phosphate demand is less than that of tomatoes. Lessons learned…the algae will need to be kept in check to prevent the use and subsequent depletion of nutrients intended for the plants. There are still 5 pods which have yet to produce seedlings. No surprise here as the seeds used were labeled as poor performers with an average 56% germination. I may plant some lettuce seeds in these pods to see if the leafy vegis fair better.

    The tank remains relatively stable with an average temp of 65 F +/- 2 degrees. With the added thermal storage capacity and only passive heat, the greenhouse is able to maintain a temperature of ~70 F +/- 8 degrees despite outside temps of 45-65 degrees. The hope here is the thermal storage will be sufficient to extend the growing season by a couple of weeks in each direction. The surface area of the water has had an effect on the humidity level, now at ~50%, but it’s difficult to predict the extent as there has been significant rain over the past week. In any event, the seedling in the soil beds are making substantial gains and will need to be transplanted to the outside beds sometime soon. BTW, rule of thumb in these parts is nothing in the ground before Memorial Day.

    The filter has cleaned up the tank & only traces of dead algae remain. The power assessment for the filter remains on the ‘to do’ list. The water is the color of a very weak, herbal tea but is odor free and otherwise relatively clear. I hope to siphon off 10+ gallons of water this weekend and replace with fresh well water if time permits. This should clear the water even more & may provide a minimal increase in phosphorous and trace minerals. The removed water will be used for the plants in the greenhouse’s soil beds so nothing is wasted. The addition of bone meal or compost to the tank may also be needed to boost the phosphate level but I’m unclear if either is a viable solution…lots of knowledge gaps on my part so more research is in order before I pursue this option.

    The fish are content & continue to grow. I’ve expanded their diet from a strict regiment of night crawlers to now include stale bread and a variety of bugs & snails from the garden. Let it suffice to say that the chickens are less than happy about the loss of their ‘treats’. The lighter demand on the vermiculture system has given the worms the opportunity to reproduce. I found two patches of tiny worms in the box last night...hope that this is the beginning of a self replenishing system.

    Enough said…as with all facets of life, learning as I go. Peace to all.