Detrivores

[Miguel Afonso]

Detrivores have an important role to play in aquaponics. They take insoluble nutrients that are unable to be taken up by plants and make them more soluble so that they become available plant nutrients. Let us know some of the welcome detrivores that have landed in your systems, and others you have introduced. Earthworm, gammarus, shrimp and other stories welcome...

[TCLynx]

Well of course we have the wonderful worms who spend their days and nights crawling through our systems slurping up the bacteria that break down the solid wastes and encouraging all sorts of beneficial bacteria to flourish and continue breaking down all the detritus.  Worms can live underwater even provided the water is very well aerated.  Worms don't breath air but rather take in oxygen by osmosis through their moist skin and therefore can survive under water as long as it is well equipped with dissolved oxygen for them.

 

Worms can also get to the craziest places too.  I have found them high overhead crawling around among the algae growing at the inlet plumbing to my towers.

[TCLynx]

Snails.

Now in my system snails don't seem to have much interest in the plants, they mostly seem to be aquatic snails and are probably eating detritus and algae.  However, my relationship with snails isn't quite as happy as the worms.

The snail shells are really good at getting caught in any small plumbing orifice and I regularly find myself needing to remove them from the feed caps to my towers and the spray bars in the fish tanks and occasionally they have even messed up the operation of an indexing valve.

But I'm not about to go to any efforts to get rid of these little tiny aquatic snails since they are only a minor annoyance and I doubt I could get rid of them without getting rid of the systems completely.  My catfish and bluegill seem to eat them when they can get to them.

[Miguel Afonso]

There are an array of native fresh water clams/mussels in North America, worth experimenting with. Bivalves(mussels/clams) are an excellent introduction to an aquaponics system as they are able to fix volatile phosphate into the water, thus making sure it sticks around or taken up by plants. They are a curiously high filter feeders, eating detritous, plankton, algae etc. and hence keep water the clean. A typical fresh water mussel can pump up to 8 gallons of water per day, and completely filter a gallon a day. The down side is that they can take up nitrates, but that means you can stock more fish. 

[Miguel Afonso]

Speaking of really cool detrivores, I am in the process of building a biopod to breed soldier fly larvae. The plan is to feed theses wonderful little buggers food scraps and weeds from the garden. After performing their duties as detrivores(making compost) they will ascend a shoot to fall to their demise inside the fish tank. Ok, I know you think that I am being a little bit of a cruel bastard like that kid down the road that would fry ants with his magnifying glass, but in my defense I have plenty of other compost bins in which these welcome little critters can get to work and still complete their full life cycle. 

 

If you are interested in building your own biopod I have several videos on my website showing you how it is done. www.urbanfarmguru.com. Let me know if you have a better way...

[George]

The fish should love it and it doesn't seem cruel at all to me.  The biopods can be quite productive.  Do you have any concern about dropping more larvae in the tank than the fish can eat?  GW on the pond boss forum wrote about planning to run a subterranean pipe out to his pond to feed fish - don't know if he actually tried it.  I'll look at your designs.  Thanks.

G
Miguel Afonso said:

Speaking of really cool detrivores, I am in the process of building a biopod to breed soldier fly larvae. The plan is to feed theses wonderful little buggers food scraps and weeds from the garden. After performing their duties as detrivores(making compost) they will ascend a shoot to fall to their demise inside the fish tank.

[Miguel Afonso]

You can regulate the amount of larvae by the amount you feed them and you can always move the bin to your chicken pen or let the guys escape.

[George]

Yes but but regarding the direct chute from biopod to fish tank, that might be difficult to regulate.  I wouldn't want uneaten larvae to accumulate in the fish tank.  Black Soldier flies certainly have a place in permaculture.  I think it's just amazing the way they dispose of our kitchen waste and then conveniently harvest themselves.  Even if we didn't have use for the larvae, it's nice to have them for waste disposal and they do produce castings, although less than earthworms.  In our regular compost we tend to have both earthworms and BSFL.

Miguel Afonso said:

You can regulate the amount of larvae by the amount you feed them and you can always move the bin to your chicken pen or let the guys escape.

[TCLynx]

You can always use a bucket under the self harvesting shoot and then feed the larva to the fish by hand so you can watch to see if they are all eaten or not and any excess, well my chickens usually beg for the BSF larva so actually not many of them make it to my fish tank.

[George]

Chickens are the most food-obsessed creatures I've seen.  They love BSFL but then again they don't reject much of anything.

TCLynx said:

well my chickens usually beg for the BSF larva so actually not many of them make it to my fish tank.