Backyard Aquaponics
A place to discuss aquaponics

Hi TCL! Yes. I agree. I found this....



here..... http://www.agribusinessweek.com/tilapia ... t-century/

I have stopped feeding cornmeal to my fish as I used to. Didn't like the oil slick that seemed to form on top of the water either.

Is true. And the vege oils used are hydrogenated.... a whole other story!!!!

We actually need a balanced mix of Omega 3,6 and 9. Cold pressed.

purslain is a really good source of Omega 3 (Some references will call it the best terrestrial plant source)
Now if I can just figure out how to get the fish interested in eating it.

http://www.slashfood.com/2008/08/08/tired-of-the-garden-weeds-eat-them/


I've mentioned this plant in the past in other threads. It is supposedly a very salt tolerant plant. It is sold as a cheap annual plant in garden centers around here though it and several related plants can also be found wild around here.

Yes. It is an excellent plant. It grows as a weed around here andd I have thrown it into a salad on occasion. Didn't know that about the Omega 3. Good to know!

I've nibbled on it here but not used it much in food yet. I can't really seem to get the fish interested in eating it so far though. I notice that different varieties have different flavors, some are pretty strong and bitter.

Yes I have noticed different varieties too. Some with a red stalk and some with green. I have never tried the red-stalked variety cos wasn't completely convinced it was purslane. I wonder if rabbits would eat it? Then feed the rabbit droppings to the fish.... You got rabbits TCL?

no rabbits, only hens. Would like them to eat the stuff to give us the omega 3 eggs. I need to get some flax seed for them.

Neat idea! I did see your hens ... I heard flax seed is best ground up to access the oils. Maybe the birds don't need that.... eat lots of seeds naturally. I bet they would take purslane. You tried them yet? I also love growing "Fathen" - also know as "lambs quarters" - for them.. and comfrey. Mine used to take both. Have to get again. Was fun... Good to integrate with AP.

I'm finding that the cheap feed I can get at the near by tractor supply doesn't seem so good for the system. Lots of solids build up, more than I would expect for the amount I'm feeding.

So I got another bag of the more $$ stuff from the aquatic place but reading the actual detailed ingredients makes me not want to feed that stuff so much either though it will probably improve the water quality over the cheap stuff. The first two ingredients on the high quality 36% protein aquaculture feed are soy and corn.

Makes me want to increase the veggie stuff I give the tilapia, at least the omega 6 and omega 3 ratio on the sweet potato leaves is far better than corn and soy. And perhaps I need to get the bug zapper to hang over the catfish tank. I'm not sure what else to do to improve the feed for the catfish since their natural feed is usually other small animals. I guess the BSF larva and worms should be a bigger part of the catfish diet.

Tends to suggest that you could/should cut back on the feed TCL... either they're just not eating it because they dont like it or they just dont need as much as you're giving them...

Three feeds a day..... have you worked out roughly the biomass in your tank??? ... ie total weight of the fish.... => number of fish x ave weight

Multiply this by the required % feed rate = > daily feed ration... divide by three to get the required ration for each feed....

How's it compare to what you're actually feeding....??

It's not going to be accurate (in terms of efficiency).... given you've got mixed sizes... and your biomass calcs are going to be an estimate....

But I'm curious as to how the figures compare to what you've actually been feeding...

Of course... you may already be using this method anyway....

Unfortunately, I don't have a good way to weigh anything. Only a bathroom scale.

In any case, I'm cutting back on the amount of that food. I had slowly been bringing it back up to the pre-overfeeding incident levels but it seems that since the incident, I won't be able to bring it quite back up to those levels and I'm thinking it will be better for all if I reduce the pellet feed even more in favor of healthier treats. Should cut feed costs too if I can feed them more on stuff growing around here. It isn't like we are actually going to eat enough fish to need max grow out speed anyway.

How much am I feeding exactly. Well a 20 lb bag of the stuff will last over a month for the tilapia. Most of the tilapia are over 6 inches and a few are probably eating size but I don't actually know what any of them weigh. So if it takes 40 days to use 20 lb of food Then that tank is getting perhaps 1/2 lb a day. That tank has about 100 tilapia and 5 catfish.

I was looking on a nutrition facts web site comparing the omega 3 and omega 6 levels in farmed and wild catfish. Wow quite a difference.

http://www.nutritiondata.com/facts/finfish-and-shellfish-products/4257/2
Fish, catfish, channel, farmed, cooked, dry heat
Total Omega-3 fatty acids 370 mg
Total Omega-6 fatty acids 1472 mg

http://www.nutritiondata.com/facts/finfish-and-shellfish-products/4255/2
Fish, catfish, channel, wild, cooked, dry heat
Total Omega-3 fatty acids 476 mg
Total Omega-6 fatty acids 203 mg

I actually want to give what can be grown here easily as feed when I go commercial. No commercial pellets at all. Keep overheads way down and I suspect..... still ready and willing to prove......tastier, healthier fish and human consumers. It is the extreme variety of such a diet offered the fish that is superior to commercial pellets. Not shooting down the use of such pellets.... but very keen to replace the need for them as costs keep rising and part of this exercise is to enable the poor to feed themselves with AP

I think tilapia are opportunistic feeders and take most things. (Protein is the main challenge as you have pointed out previously. Bugs, worms, eggs and even protein waste off a commercial enterprise could sort this perhaps.)

Algae is an amazing source of Omega-3 fatty acids, and the tilapia is superb in being able to filter this as food. We can eat spirulina and chlorella. Plants contain short chain Omega-3 and when we eat it it converts to the longchain Omega 3 which is more readily available to our cells. The tilapia convert the algae short chains into longchain Omega 3 too. The one thing about the short chain omega 3 found in plants is that it is protected by vitamin E and not so in fish. The vitamin E prevents rancidity happening too rapidly.

I am looking at producing my own "pellet"... I might just buy a pellet machine one day.... of ground seeds (rich in O-3) and bound with egg. Sunflower, linseed (aka flax), sesame and pumpkin seeds.... Pumpkin seeds are also known to get rid of intestinal worms.....I think that these seeds ground up into a flour and bound in egg.... done on the day to be given.... will give the fish full access to the nutrition.

Leafy greens are also a rich source of O-3... some more than others... as we have been discussing



Interesting stuff!!

is an incredibly interesting link, TCLynx

just spent an hour on it composing some recipes and saving them
allows you to adapt ingredients and portions of them to balance out nutrition

great tool!

deserves a "sticky" (whatever that is, haven't quite understood) or a thread of it's own

many, many, many thanks

Frank

we are obviously thinking along the same lines, Chelle
But every now and then we must recall ourselves to reality:
we cannot possibly produce our own food at the same price that specialized companies do unless we don't count labor
there are only 24 hours in a day and I for one don't want to spend them all working
even if I don't consider many of these hours as work, but most of them as fun (hopefully this will last)
still the number of hours in a day is limited
we must keep that in mind if we want to keep the fun

frank