Fish on Trial.

What will be the verdict?

We have started a feed trial with Jade Perch. The idea behind the 12-month trial is to see just how well the Jade Parch will grow being fed anything they will eat that can come off the land rather than use fish feed pellets that contain ocean derived fish meal.
With a view toward long-term sustainability, I feel we need to discover and refine feeding methods that are not dependent on ocean fish stocks. Seems elementary, but I really want to see just how well it will or will not work.

Aquaponics policemen.

Aquaponics policemen.

Expectations: I believe we will get the fish through to the 12-month point in a healthy state, after all, Jade Perch in the wild eat plant material and algae etc. I imagine that we will see slower growth in the plant fed fish but I believe they will be very healthy.

Time will tell.

In my INDY 23 system I have 2 x IBC tanks that are all part of the same system. Same water same pump system etc. I feel it is an ideal setup to test two identical batches of fish that share the same conditions except fo the feed they get.
There are 65 Jades in each tank. The fish are supplied by Ausyfish at Childers.
They have been in the tanks for one month. The trial feeding started 1st March.
Weigh in on 1st April.

The batch of 130 fish were evenly divided as to size as near as we could. Very difficult when they are so small approx 10g each fish; so we started with 650g of fish density in each tank.

Tank "A" is been getting up to 50g of 2mm pellets per day.
The pellets are as below
Crude Analysis
Protein Min 35 %
Fat Max 10 %
Moisture Max 10%
Ash Max 11%
Ingredients =
Chilean Fishmeal, Wheatflour, Soybean Meal, Shrimp meal, Squid, Aquamix,

Tank "B" is getting a diet of lettuce, cooked carrot, cooked pumpkin, Kang kong leaves, honeydew melon, eggplant, cucumber. It is difficult to know just how much to give tank "B" every day but we are getting better at keeping the feed up to them.

This is a piece of eggplant that they demolished overnight.

This is a piece of eggplant that they demolished overnight.

First weigh in on 1st April.
Sample of 20 randomly caught fish from each tank gave the following results.
The fish were weighed as a batch.

Group "A" = 30g
Group "B" = 23g

Group "B" have not put on much weight at all; 3g over 20 fish. So we need to up their feed somewhat.


This is the lettuce when they have stripped it of the green leaves.

This is the lettuce when they have stripped it of the green leaves.

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55 thoughts on “Fish on Trial.

  1. Will be very interesting to see the results Murray. I think you are right though, we do need to look at alternatives to feed our fish with.

    • Yes, important stuff Josh. I am enjoying the project. Finding high protein plant foods that they will eat is the challenge.

      • My Tilapia largely depend on algae and watercress and water hyacinths that grow naturally in their pond. They are on nature’s diet that serves them well in the wild. I am thinking of pulverizing Keawe, (Accacia legume tree) 35% protein bean pods, that cover all the islands. You guys have heaps of those.
        Thanks for all you do Murray!

        • Another interesting one. Thanks Nick. I will look for the Keawe Acacia legume tree. So much to learn. There is no end to it I am sure.

        • Please contact me
          ASAP i would like to start up a fish farm an i would like to grow Tilapia could you give me your contact details.
          Thank you

          • Hi Neeraj,
            Best to contact me via my regular website email murray(at)

  2. Hi Murray, this look awesome. I will also be working on my fish feed later 2017.
    For the protein, we are going to use dried moringa leaves mix with Kale.

    • I must get some moringa….takes a while to grow but should be part of the ideal diet. Do you have any analysis of Moringa?

      • Here is a moringa analysis:
        This plant really is a miracle plant! My personal favorite to eat are the tenders seed pods 🙂 taste amazing, kind of asparagus-y! The leaves however just taste “green” I think of the leaves as my vitamin pills. Dead simple to grow and they grow extremely fast even here in the Sonoran desert. They just need a little water to get them started and then become reasonably low water using.

        • Thanks heaps Liz. I will be looking for a tree or two today. Someone here must have some. I hope.

          • Moringa grows great from seed! If you can find some seeds, that will get you going in short order. Here in Phoenix we can get a tiny seedling to a 4.5′ sapling in 2 months during our hot summers planted in the ground. I’ve also had good luck growing them in large wicking barrels too. They are frost sensitive, so wicking barrels that you can move to a protected area in winter are really useful.

          • Hi Liz, I have some seed on order, but that will take a while to grow. I need to put the call out to find someone locally who has a tree or two. I think I could grow the Moringa tree here OK. Our climate is very mild.

  3. I know it works on Tilapia. Mine have done fine for years on romaine, kale, Okinawa spinach, compost worms, grubs and soldier fly larvae. Also I give them what is left over from my organic corn chips, after I pulse with a bullet grinder. Both blue and yellow. They love that. I don’t know anything about jade perch. Looks like they love lettuce. 🙂 Looking forward to your results Murray. Cheers from central Florida.

    • Hi Ken, Don_in_Odessa here, also in central Florida. Just started experimenting with Katuk and Moringa. I tie the individual stems and hang them on the side of the tank to let the fish pluck the leaves off at will. Only been a month, but they are eating the leaves. hey like the Katuk better than the Moringa. Still feeding them their regular diet (Pond food I buy at Tractor Supply) but I am slowly lowering the amount as the fish get used to the new stuff. I have found over the years they will eat a wide variety of stuff I grow in my yard, much the same stuff including common weeds as I throw into the chickens. It is a bit of chore to harvest, tie and remove the old stuff from the tank every day though. I must admit throwing in the feed pellets several times a day is a whole lot easier. I wish I could get away from commercial feed all together. Seems all of it is mostly filler that dirties up the system quicker than I would like. Can’t really justify the expense of the more expensive foods anyhow.

  4. Hi Murray, the one glaring thing that is missing from group B’s diet is protein, protein builds muscle and fish are just a big muscle so they’re at a real disadvantage in this trial, I gave you a fish food recipe in last years course that contained Lupins, there is nothing higher in protein than Lupins you can get them from stock feed stores for about $20 per 20kg bag and mill them or drop them in whole and let them soften or soak them then drop them in, another good source of protein can be gained from spirulina or algae if you can grow some.
    My Jades are 15 months old and weigh on average 900g and they’ve been given that lupin recipe, if you’ve lost it I can send it through to you.
    I hope this helps you even this trial up Murray

  5. I agree with the assessment there is not enough protein. You need higher calorie feed going into tank b! There is a non-profit group here in Phoenix (Gardenpool) that are growing tilapia without commercial feed very successfully. But they are using chickens roosting over the pond to boost nitrogen in the system to grow lots of algae. If you are squeamish about chook droppings and potential salmonella, you could have a separate system just growing algae… But algae really drives their system. You can grow enough algae and duckweed to feed the fish a great diet supplemented with soldier fly larvae in order to get the protein, fat and calories they need but not on the fish waste alone! I should also mention they have figured out how to feed their chickens “off the land” as well using duckweed, insects, snails and such.
    Here is an article advocating algae production to add to cattle feed because of the protein and healthy fats it contains:
    Food for thought! 🙂

    • So true Liz. I am not keen on the chicken poop directly into the tank for the same reasons you have mentioned. It is a good idea to use them as you suggest, in a separate side way. Thanks for the links. I will follow through on that.
      Isn’t it great, the community of Aquaponics….The collective knowledge base.

      • Thanks Murray! You were my introduction to AP and I’m only grateful to be able to share bits I’ve picked up along the way 🙂

  6. HI Murray .. I think if you really want to give this a good go you need to shred and dehydrate the feed recipe you have .. Then too make (as it’s only a small number of fish) .. get a pasta roller, roll it out, cut it into spaghetti .. then cut into pellet size pieces and dry .. or get a a old fashioned meat grinder .. and extrude and cut .. onto a screen (bit of mosquito net stretched, and stapled over a wood frame, with a fan on the bottom .. to dry it out) … as you put it through the mincer cut it flat against the face to make small pellets .. like chicken feed .. then dry them … I think the problem is you have too much water content, feeding fresh food .. so it’s not a fair trial .. dry and concentrate the food … it’s like us eating 200g of steak or 200g of jerky … i’m going to be giving it a go too, here in Thailand .. just getting the last of the import papers sorted for the jade’s, for the new farm, in Bangkok . James Harrison @ GreenEvolution Thailand

    • This is good James, thanks. Makes sense. Yes feeding them lettuce and the like is not concentrated enough. I am surprised just what they will eat. The guy at Ausyfish (the hatchery where we get our fingerlings) reckons they will eat a great variety of land based material. As you suggest, whatever it is we need to make it more concentrated. I will keep you posted

      • This is where the protein rich duck weed comes in .if you can find it .. the wolfya is the highest in protein at over (40% dry weight) .. but it needs to be dry and ground to powder, you will be shocked at how little you get, if you dry a bucket full … but this is the only way concentrate the plant based proteins…. I can send you some moringa seeds if you want … but I think your (and my).. next move is going to be building a big solar dehydrator, and running some experiments … Im also getting our fish from Bruce.. if I can get the import docs in time .. befor they get too big to ship over here … if you’re in Bangkok any time .. stop in for a visit .. should have things finished, and water moving by the beginning of May ..

        • Hi James,
          Thanks for the offer of the seeds but Australian Customs would not be impressed with that. I sure could do with some for sure. I have ordered some of a guy in Townsville so hopefully they will turn up soon. Need to find someone locally who has a Moringa tree so I can get some of the leaves etc. Have loads of duckweed but not the type you speak of.

  7. This is going to be an interesting experiment. I look forward to the results. Why are some of the food items cooked?

    • Hi Hugh, we cooked the carrot and pumpkin because the fish are so little and the raw carrot and pumpkin so hard. Since writing the blog post I have thrown a raw carrot in and they have been nibbling at it but obviously it is a bit difficult for them. Long way to go. We are only a bit more than a month into the trial and collectively we will learn a few things I am sure.

  8. wish you luck.Will be looking forward to further results and jade are now 5 months old and doing
    well on your feed.
    Thanks Geoffery.

  9. This is really interesting Ive been supplementing my JP pellets with left overs from the kitchen made into ice blocks usually cooked rice or couscous with lightly mashed lettuce, peas, stale blueberries, with a dash of Vietnamese fish sauce. They go mad for it.

    • The Vietnamese Fish Sauce is an interesting touch Jock. Maybe that will make them eat otherwise uninteresting stuff. Thanks.

  10. good morning,

    we have tried similar tests in thailand with vegetables and also sprouted seeds. same result low if any weight gain. Problem is lack of protein. Next test will be to grow and use crickets as the protein source.

    pete & derry

    • Hi Pete,
      Thanks for the feedback. Yes, looking for high protein vegetable foods. Almonds, soy bean, quinoa are very likely ones. I tried growing crickets a few years back and it was a lot of work, but a good idea. That is the trouble, it is so easy to throw a few fish feed pellets into the tank, but we will not be doing that for this trial.

      • That reminds me – maybe mealworms would be a good supplement? They are ridiculously easy to grow and you don’t have to worry about them jumping or flying out of their plastic tub (unlike crickets). I’ve grown them very successfully in a shallow plastic bin. Just put down a few inch deep layer of wheat bran, sprinkle on some brewer’s yeast for added nutrition and then put a potato cut in half (cut side down) for moisture. All set. Keep putting a new potato in as the old one dries out and top off occasionally with more wheat bran. endless supply of fresh protien. They don’t smell and I’ve kept them inside just under the bed or furniture out of sight to keep them cool in our horrid hot summers.

          • Here in the US they sell mealworms at our local pet stores to feed lizards and such, you can buy a cup full of them live. Maybe try a bait shop as well.
            PS. Make sure you just get regular mealworms, not the “super worms”. PPS. Don’t put a tight lid on your worm farm either, they like good air circulation! Although, speaking from experience – if you have a cat, you might want a screen to cover them 😉

      • Hi Murray, just wondering how your fish food trial went and also wondering if you ever tried hemp seeds. I believe they are high in protein

  11. Great to see Murray. I feed my jade perch on only what i grow and they seem to do really well. Although i havent done any real scientific studies though. I feed them on left over greens from the aquaponics, soldier fly larve, worms from the worm farm and mosquito fish that i grow specifically to feed the jade perch. The mosquito fish form part of the aquaponics system as well as the red claw. All in all it is quite a balanced system.


    • Hi Graham,
      I have not had any luck getting mine to eat the mosquito fish in the past; that is, pellet fed fish. I have a big population of the mosquito fish in my water hole down the back. Must catch some more out to give it another try with these new little fellas. Thanks for the reminder Graham.

    • Thanks Josh, that is very useful info. I will study that and see what else I can get that will be useful.
      Ordered a Moringa tree today from Daleys Nursery at Kyogle. An Apricot tree at the same time. So, looking forward to that coming. I will put it straight into a wicking bed.

  12. Hi, Yes i am very interested in starting up a fish farm.
    could you give me more info on how to startup and more info about food etc.

  13. Will the fish eat Black Soldier Fly Larvae? We have heaps growing in our compost which we feed to the chooks regularly and I’ve been told they can be fed to fish in an Aquaponics or Aquaculture system too

    • Hi Jules,
      The fish are not too keen on them unless they are mixed with something else to make them more attractive….we have found.

  14. Hey Murray has been almost a good year now since the start of the trial. Is it time to weigh in?
    PS would love to see seans lupin recipe too as would love to slow grow my fish.