Feed

[Nate Irish]

Hello like minded friends I am setting up a system that I hope to raise Tilapia, its been my understanding that these fish are vegetarians and you can grow their food source. My question is what kind of foods can you grow for them and how? thank you for all the information that you all provide it is so helpful and you are helping a community of people wanting to become self sustained

[Sheri Schmeckpeper]

It's the shipping that kills. Right now we're set for food for a while, so we have a little time. We also have a good sized group who are willing to go in together on a shipment if needed. Things are in the works, I think. You made a good point about shelf life. Unless we can show enough demand, it's hard for a small shop to get the better prices.And yes, there are some who are Purina suppliers.

Let me ask this: when we switched to Purina, our tilapia slowed down on eating. They don't seem to like it that well. They've been on it for a couple months, but they seem to eat it only because they're hungry; of course, that might not be a bad thing. I'm not sure if they'd slowed in growth, but I suspect they may have. Have you ever observed anything like that? (Hmmm....maybe I should start eating Purina...)

[TCLynx]

It will depend on which aquamax you are using.  I like the Aquamax 4000 Dense culture feed and it seems to work well for my fish.  However, I haven't been very happy with the 400 grower feed, apparently they use feather meal in it to up the protein content and the fish I guess don't digest that well.

[Sheri Schmeckpeper]

Feather meal...That's a new twist on chicken by-products!
We have the 4000 Dense. I'm not too concerned about it as long as they eat. After we rebuilt our system I'll be working on growing our own supplemental food sources, too.

[Brandon's Fish Farm]

I have been growing and feeding mine duckweed for years also you can try green water culture which is just algae in the water "a little chicken manure goes a long to jump start the algae and the fish grow 2 times faster. I have tested this with Nile and Blue both.  As for the duckweed still water lots of organic matter sticks, leaves etc.  Mix 1 time per week vigorously to make the duckweed sink and then realign itself on the surface.  This seems to keep white mold away...Hope that helps..

Rod

Brandon's Fish Farm

<*(((>>>>/p>

[TCLynx]

I'll add a little caution to Brandon's mention of using chicken manure.  I would recommend against if you are doing this in and aquaponics system!  If you eat any salads raw, avoid the warm blooded manure being added into your aquaponics water!!!!!!!

If you use warm blooded manure to fertilize duckweed, I would recommend drying the duckweed before using it as feed for your aquaponics system.

If you do green water culture with manure to grow fish, do it separate from your aquaponics system.  See the fish get cooked and rendered safe even if the water they are in gets tainted by the manure.  Most people I know don't cook their lettuce well enough to render it safe no matter how well you wash it.

Very well aged and cured compost may be safe and fine in contact with aquaponics water.

Warm blooded Manure is not safe unless sterilized.  Some people may get away with it but I've heard of people actually eating dung, doesn't mean I want to put manure into my salad.  I far prefer to let nature convert the manure into something far more pleasant before I grow my salad in it.

(Sorry, just my standard public service announcement.)

[David]

Duckweed growing is dead easy.  I dont recirculate it at all. It does best in slow moving or stagnate water. kiddy pool is a cheap bed option for a duck weed culture.

John Wroten said:

I to am wondering how I can supplament the fish store food with vegys. I want to grow duck weed but I am yet to read how to set up a grow system. I see on u-tube that they use kiddies pools, but they dont tell how they recirculate the water. What temps it needs to be, water and ambient temps. I know there are folks out there than can tell all the ins and out. I'm teady to copy...John

[Sheri Schmeckpeper]

Successful duckweed growth has a lot to do with the environment - air humidity, air temps, water, light, etc. the "normal" techniques fail here in the AZ desert. Duckweed is not a natural plant here, for good reason. We have extremely dry air, our sun is too strong for duckweed, and our water PH is very high. When we follow the normal advice, our duckweed gets yellow and algae takes over, eventually killing the duckweed.

We copied a friend who was successful after breaking all the rules about duckweed, and now we are growing it very easily. We use a simple, timed ebb and flow system (separate from the main system) with plenty of water circulation. The circulation is needed to cool the water; a kiddie pool gets too hot. Our system is in a totally shady location, again to keep the heat down.

One of our trays is fed by a lot of fish and has a bubbler in it; it's doubling daily. Another tray is fed by a few fish & has no bubbler. It's healthy, but growth is much slower. My next test will be to aerate the other tray to see if it improves growth, or if the difference in growth is strictly due to nutrients.  It's taken about a year of trial and error by a few locals to get the system down, but it's working great!

[TCLynx]

Great info Sheri!!!!

     I too have experienced difficulty with growing duckweed in a "stagnant kiddie pool"  Even in shade it still failed or at least didn't thrive.  But I have a trough with some bubblers, and recirculation with the big system and mostly shade and it is thriving here in Central FL.  Now we do get humid air but it is hot here and too much sun kills the duckweed in summer.

I have also learned that a heavily duckweed coverd 16 foot long by 30 wide inch tank can have all the duckweed completely consumed by 12 juvinile (between 3-5 inch) tilapia in under a week if you are not feeding them anything else, the duckweed won't keep up.

[Sheri Schmeckpeper]

Wow, that's a lot of duckweed!

I read a study (I wish I could give credit) that said you can feed tilapia 50% dried duckweed with 50% feed with no decrease in size, but if you go over that, growth slows down. Since duckweed is mostly water, I don't think I could ever grow enough to reach that 50% mark, but it's a nice supplement and I'm happy we're able to grow it now!

[Phil Slaton]

Wow, some exotic ideas.  I am not very exotic in the food department. One thing I feed 'em is finely chopped up spinach; guess where I get the spinach?  They love it.

[Sheri Schmeckpeper]

A great cycle, isn't it, Phil?

I pulled the air stone from our best duckweed tray because I needed one for a fish tank in a pinch. The duckweed is still doing well, but has definitely slowed down. I've also noticed that it grows more prolifically where the water is most active (by the stones or where the water pours into the tray). So, at least in the extreme heat, duckweed does prefer oxygenated water!

[TCLynx]

Yes, it like oxygenated water but not too aggressively agitated.  Then again, I've accidentally grown duckweed on wicking mat or even in the tops of my towers, apparently it just needs wet but not actually having to be floating in the water.