Backyard Aquaponics
A place to discuss aquaponics

Hi Iggy;
I have 200 channel catfish, 250 hybrid blue gill, and 50 yellow perch coming in April. That is to Michigan. With the weather here, I am planning an 18-24 month grow out. I will use two tanks, so I can start small fish every spring and grow out the larger fish in the bigger tank (1,000 & 3000 gallon concrete tanks in a greenhouse). I will only do Tilapia if I do not need artificial heating. I just built the greenhouse, so a year of experience will help a lot.

Thanks for the reassurance, Gary -- I think it just might work this summer when the houseflies are troublesome -- I'll have the perfect suggestion to effect a remedy...

Doug -- Yes, that sounds about right... I've got a bit less winter than you, but winter still it is... Colder water, lower energy, slower growout. Just plan a crop rotation. I'd like to do Tilapia (Oh, so tasty) but the heating co$t might be the killer.

I'm looking first at an indoor "nursery" rig, (378 liter) which so far looks like it will work on a 5-watt air pump, 15 watt water pump, a hundred or so watts worth of LED lights, and then... (ACK!) a 300 watt heater! OK, time to study up on those passive solar hot water panels...

But, if I can generate plentiful fodder, I think I could manage to grow-out a batch of Tilapia outdoors in the spring/summer... Hence the interest in BSF...

Thanks!

Will Tilapia eat BSF? Thought they were strictly greens eaters.

Tilapia are first and foremost: HUNGRY! They'll take your fingers off, given the chance.

Yes, they are vegetarian, and I have heard they will develop problems if fed too much protein. The fry need higher protein than adults. Fry need about 40% protein, fingerlings 32-36%, and larger get 28-32%. I have 40% flakes for the fry, and 35% floating pellets for everybody else. Plus various leafy waste, of course.

From what I've read tilapia will definitely eat BSF larvae. If not then my over-arching plans for sustainability need to be reworked. "Duckweed + BSF = $ustainability!"

IK, your 300 watt heater won't be using 300 watts all the time, and if you insulate the heck out of everything it mightn't be such a scary energy drain.

I have been reading about BSF - (fascinating) and Tilapia, trout, and swine were all mentioned as things that eat the BSF. Tilapia are omnivorous. They will eat lots of greenery, but will also eat other stuff (probably anything that fits in their mouth).

I would say try it and see. The things that I think would be interesting are to raise BSF and mosquito larva as live food, and sprouts for the greenery.

Mosquito farmer, now there's an under-exploited market!

They say that if you are harvesting the larvae, it will reduce population. Mosquitos are going to lay their eggs, so give them a place to, then strain out the larvae and throw them to the fish. Fish get protein, mosquitos get eaten, the eaten mosquitos never fly, never bite, and everyone's happy. (except the mosquitos, but I'm not going to get broken up about them)...

Neat! Do you use one of those propane things to attract them?

I'm sure the tilapia would be happy to eat BSF...just give them more duckweed than BSF.

I don't think you need a propane thing for the mosquitos. Just put out a bucket of water and strain it every few days.

Right you are, Janet!

I read something about attracting them and harvesting them. I can't find it now, but the idea is that to reduce the population there are basically 3 methods:
1- gas the world and poison everything, hopefully killing more mossies than other stuff
2- remove all places that they can breed (remove all warm blooded animals and/or all standing water [nearly impossible to remove _all_ standing water])
3- create an ideal environment for them to drop their eggs, then harvest them as either egg clusters, or larvae, and feed them to fishies.

2 is the conventional wisdom, but since you can't eliminate all standing water, 3 is starting to get more play time. There are several other pests that are controlled by interrupting thier life cycle. The mosquitos need to emerge from the water alive in order to bite you!

On the Bay Islands in Honduras they are in the midst of an erradication program that allows the mosquitos to lay eggs then they treat all standing water with a mixture of cocnut milk and something els. It kills the larva without damaging the environment. They say it is working.

Okay, I left out option 4, dt. Modify 3 and kill the eggs in a different way!

Sounds like a good option. Would the coconut milk and "something else" make it safe for the fish? if so, that would be a good method, providing fish food and ensuring that the mossies can never bite anyone.

Hi,

For our Northern hemisphere friends, I'd suggest that they plan on growing enough BSF larvae and duckweed during the milder months and preserving a surplus to feed during the colder months.

Dried duckweed and BSF larvae are around the 40% protein mark. BSF larvae can also be frozen. I haven't tried drying BSF larvae (and I'm not sure that I'd bother as long as I could freeze them) but drying duckweed is very easy.

Dried duckweed would be no different to feeding flakes - except that it would probably float better.

Although I'm harvest fresh larvae on a daily basis, I feed my fish with frozen larvae (straight from the freezer) without any apparent issue.

Gary

Hi Gary, not to nit pick, but you said Duckweed is 40% protein? Or just the BSF are? If Duckweed is 40% protein, that is very impressive. I wonder if soybeans are 40% protein. Maybe I just parsed your sentence wrong.

I wonder if channel catfish will eat duckweed. Does anyone know? If not, I guess I should try when mine are here and acclimated.