Backyard Aquaponics
A place to discuss aquaponics

Have a freshwater soak about 1/2 a meg in capacity stocked with silver perch (various ages), marron, glass shrimp and yabbies. The only food inputs that go into this system are whole farm grown lupins once a fortnight. Lupins are rich in protein (33%) and are cheap. They are commonly thrown in water to feed yabbies and marron but in this system I think it is possible it generates food credits for the fish as well in two ways:
1. Lots of young crustaceans to predate on.
2. Lupins germinate and drown so presumably there is a window of grazing for omnivorous fish. Also noticed you can seem plumes of algae around unconsumed seeds as they degrade.

I am passionate about finding cheap ways of driving the productivity of these systems and other systems. Perhaps we should be able to buy lupins from our local AP store? Think it is good to throw in proper pellets occassionally for an omega 3 hit.

The other key to this system is I have utilised old PVC and air seeder hose from farms cut in 30cm lengths to produce hundreds of hides in the freshwater soak. The key is creating habit for crustacean multiplication so the fish can indulge. In 12 months I have thrown fish pellets in maybe 5 times and there are around 40 fish of mixed size. Just keep adding 20 silvers every 6 months.

Reckon we could get more shrimp in the system also if we had more habitat for them. Used shadecloth could be all that is needed? I have observed these little fellas in native habitat down south and they love lots of nooks and crannies.

Would love a fish species that can breed in this system.

For the APers in larger water bodies (pools) there has to be better opportunities to drive biological porductivity because you can get the crustacean aspect of your system to be productive?

Yep... lupins have been studies as a potential fish feed quite extensively... especially in WA....

A search of the forum would bring up a couple of old threads where this was discussed...

With all the "young crustaceans" available... (eating the lupins)... I wonder how much the fish growth might be attributed to the lupins... rather than the crustacea...

Wait.. lupin... as in flower?

Do you have a field you harvest from, or do you have to purchase seed? I don't think they'll grow well here, at least not in the valley. But, maybe I'm incorrect.

And... no, while there USED to be wild crawdad... they've gone with the expansion of construction.

Or... maybe I should check some of the washes...

For the Americans on the forum you could use whole soybeans or peas. Any legume seed high in protein. Even canola.

Marron, yabbies and shrimp are all bottom feeding omnivours. They will be munching on the lupins, vegetation and a bunch of micro-organisms and water life. The silvers will be eating them. Its a great little eco-system. Dog eat dog lifestyle.

It wont be long before the yabbies will take over the soak floor, make sure you trap regularly to keep numbers down.

A soak or dam cant be replicated with a pool or large hard bodied tank in my opinion. Nature is not an easy thing to copy.

Not well anyway charlie, however maybe a "honeycomb" of pvc piping of the right size, stuck around the walls of the pond, then a mud floor would surfice to allow for a half decent population?
I suppose you also have the problem of yabbies liking muddy/dark water to hide them from the light, most people wouldnt want mud water for their fish taste and the like.

Be careful what you put in your ft. I have tried a mix of lentils, black beans, kidney beans, chic peas, Harricot , soya, black eyes, mung beans, buckwheat and wheat. Some of these, probably the smaller sized ones, go straight through the pump, block up water outlets all while growing as one would expect in ap

The only reason you have a nice little ecosystem happening is because you have a limited number of fish in there. If you had a species of fish that did breed as their numbers increased they would eat out most of the food source and then stunt being of no use to anyone. There are plenty of examples of this out there wherever Redfin Perch are present.

I have heard about them being used as fish feed but has anyone got an idea of how to process them (without high tech high energy input)? I have only seen the dried ones can you use them green?

Used to be on the WA Fisheries website... but couldn't find it...

So unzip the "Feeding Lupins To Fish" pdf.... attached...

Thank you Rupert, that has been well and truly saved. Just on a quick skip some of the results were very promising (eg table 4.7 for trout).
Do you have any information about non dried lupins? They tend to pop up in the back of my place (the blue ones) and I would encourage them if I thought I could feed them, bashed about a bit to my goldfish.

FYI Sleepe....

Lupins were looked at very seriously in WA... for animal feed and as a fish feed... and a specialised "de-hulling" processing plant built...

http://www.kalgrains.com.au/

The Australian lupin has a very good amino acid ... and mineral nutrient profile...

http://www.agric.wa.gov.au/PC_92144.html

But note.... that they were basically only recommended as a supplementary feed..

I have fed them to carp and yabbies ,All I did was soak them for twelve hours before I gave it to them .If you live in a rural area in Western Australia you can get them very cheap or for nothing.You can buy them for around $300 a tonne.For smaller fish I have put them through a hammer mill.

Lupins have been the feed of choice for yabbie farmers and/or stock dams for generations. Cheap and effective.