DIY fish feed – BSFL & Duckweed | Ask The aquaponics God

DIY fish feed - BSFL & Duckweed | Ask The aquaponics God

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The School of Aquaponics


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Written by The School of Aquaponics

We are here to push the movement of aquaponics in a forward direction. Our primary focus is help you in your adventure with aquaponics by providing you with the highest level of information. Aquaponics is still in its infancy and we predict that it will be the go to method of farming by many families and urban farmers. Our job is to ensure that they are taught correctly.

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  1. Using 100% duckweed absolutely cannot work in any instance. The duckweed is growing from the nitrification and mineralization based of the waste products which is the food itself. The fish are taking up nutrients and the waste is the overage of nutrient (not utilized). The cycle cannot support itself, food, fish, waste, food without extra inputs. The video is interesting but only analyzes the components separately, when it should look at the ingredients together. The original question actually was about all the components together. So in essence the question was not answered.

  2. I think that your faith in feed manufacturers might be too strong. My big concern is what's actually in the feed that you buy, and how many chemicals were used to make it. Has someone tried a combination of the three, or meal worms or crickets? Bugs abound and are full of protein. There has to be some combination that doesn't include anything from the ocean. The oceans need a long time to recover already

  3. Thing about duckweed as a protein source is that it is ONLY a protein source. Those formulated feeds are generated after research is done to give fish their most nutrient rich food source as possible. Yes, feed them duckweed… but think about yourself. You need protein, right? Do you think you could survive on duckweed alone? Don't you need calcium, vitamin D, zinc, sodium, etc. etc.? You need more than just duckweed. Till you find that one plant that has all the vitamins & nutrients your fish needs, you're going to have to put multiple sources together; not just duckweed alone…..

  4. This is full of holes, anyone knows if you do duckweed, you have to have stacks of trays for your duckweed, and you have to invest in a lot of trays, with algae as well. And for BSF & Worms, you are going to use the solids from your fish waste to feed them, doing worms in the ground with boards on top. is the best natural way to do it, shove them up and you will have all the feed you need. I will upload my system when its done. Its all on how you do it. the way they did it is so lame and is as if they wanted it to fail in the first place….. You have to combines Algae with Duckweed just as a base…..

  5. I watched a documentary where it said that fish meal was the main reason that farm raised fish had such high levels of contaminants. Is there a type of fish food that is not contaminated?

  6. Dude thank you. There's so much bad info out there and you provide a great service with this channel. I don't know if you covered this already, I just subbed, but I've read that tillapia will eat chicken poo. What I'm really wondering is if they eat the solids or the planktons that grow from the solids. If so, then would it be beneficial to drop the poo into a high airation situation, growing the planktons and then feeding them to your fish? Long question! Anyone?

  7. Thanks, but if I'm going to feed with commercial fish-based feed I might as well just buy my fish and veggies at the market. I don't care so much about opportunity costs; I want a system that requires minimum cash inputs and maximum grown-on-site resources.

  8. Great video! Would it be possible to form a feed using say 50% BSFL, 30% duckweed and 20% fish meal? Trying to think of ways to reduce feed input costs as we can harvest the BSFL and duckweed ourselves and buy in the addiction fish feed required. Cheers!

  9. If your feed is free (duckweed), who cares if you have to allow the fish to live an extra month to get to harvest weight. If you can harvest your fish in 6 months and 75% of the sale price of the fish was food cost, is it not better to harvest in 7 or 8 months and have food costs at near 0%? With fish ( and poultry) the profit margin of your product is determined mainly by food, not by infrastructure.

  10. YES I get it, its sub optimal … but its more sustainable… BUT OK we have to get the maximum efficiency so let's keep overfishing the oceans to feed our 'landfishfarming' untill we run out of fish

  11. For those of us backyard enthusiast, home-steader, survivalist types.. what would you recommend as a sustainable fish feed, willing to pay the time and space constraints? I'm not sure what size the average system is; Let's just estimate high and say 2000 to 4000 gallon fish tank size.

    I'd have to find the video where you work backwards to find the stocking densities and plant area for that much volume of water, considering it needs to be minimum 200mg/L nutrient solution. I believe you recommended a 0.5lb fish per 1 gallon of water for high stocking. For this example, let's say 1lb per 1gallon. The feed rate would be 60g/m2/day for 400mg/L (400ppm?) in a DWC system.

    I think the types of systems also change the required nutrient concentration. Generally, the backyard tinkerer uses media based grow beds. I have both flood and drain and constant flood. I plan to add wicking grow beds as well. Really interested to know what you think about this.

  12. Ehh….
    I think the only way to expand a business or a hobby is to pay an opportunity cost; If I'm going to pay an opportunity cost, I'd prefer to pay for something that isn't dependent on the success of my next crop.
    Knowledge is usually something you can make a return on.

    That said, It would be more worthwhile to look at whether you can afford to engage in a particular experiment. What I mean by that is, what is the opportunity cost and how can it be paid. If you have to switch all your livestock over to duckweed right now…. that's probably too rich for my blood, but raising a handful of the gunk in swirl filter and feeding it once every few weeks ain't nothing.

    At any rate…. $10.00 for a cup of duckweed is theft. It has "WEED" in the name for a reason. You can literally go out to any water way in the western US that has turbidity and find duckweed.

    Finally, for my 2 cents on fish food: look up "WoodLice" aka Pill bugs.

  13. You never stated this, but apparently your evaluation criteria is minimizing the cost of fish production and/or minimizing the time to market of the fish. I think there are lots of studies that show that when you consider ALL the energy and resource costs, that large scale aquaponic fish farming methods are inherently less efficient. On the other hand, if the objective is minimizing the cost of growing vegetables then (as long as you don't kill any of the fish) slower growth of the fish isn't necessarily a bad thing. In other words, if you're only interested in selling (or eating) the vegetables from the farm and fish are just a byproduct, then it doesn't matter that the fish are smaller. In other words, both the research studies you cite are irrelevant to aquaponic vegetable farmers. What you need to do is find a study that analyzes the payback period of growing your own fish food versus buying commercial fish meal without regard to the returns from selling (or eating) the fish.

  14. Great videos. I've subscribed today. Blacksoldier fly is $100 Australian per kilo. If I was to raise half a dozen rainbow trouts, would that be enough to last for 2-3 months?

  15. Many variants to consider in this issue. I think after this video you can up to the level eight god of aquaponics
    BTW, You can not barbecue pirarucu. He has very thick skin. Without skin, you can grill, make stew or like the Indians, curl on banana leaf, bury it inside the soil, light a campfire on top and wait for cooking. Delicious!!

  16. OK, hang on a sec. When 'formulating' fish feed we need to understand if we are feeding herbivores, carnivores or omnivores. Herbivores should do fine with 100% plant based feeds. However, Tilapia are omnivores, thus they will naturally include insects in their diet as do trout. 100% duckweed is a non-starter.

    The study on duckweed quoted here used Spirodela polyrrhiza L. Schleiden also called common duckmeat or giant duckweed. The prevalent species of duckweed commonly cultivated is Lemna minor so caution is advised when extrapolating their results.

    On the other end of the scale, 100% BSFL is also problematic. While BSFL contain good amounts of protein, they are very fatty and should be limited in the diet for this reason.

    Another thing to consider is that Tilapia have different nutritional requirements as they progress through their life cycle. For example fry < 1.5 grams need a diet of 50% Crude Protein, 16% Crude Fat, and 3% Crude Fiber whereas growout feed for fish >50 grams should contain 35% protein, 6% fat, and 5% fiber.




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