There are several options for feeding your tilapia depending on the size of your operation and the format of your grow environment. This entry will focus on systems that have the fish in enclosed tanks. This is as would be found in a city backyard system. For reference, the use of large outdoor ponds is a different system that has other options.
General feeding issues.
You want to feed your fish for maximum growth and least waste.
Your fish can go with less food or no food for a couple days.
It is better to underfeed than overfeed when you will be away from your setup. Overfeeding will lead to water fouling and fish kill.
Feeding your fish too much will result in undigested food travelling through their system, and inefficiency.
Starting:
If you are just starting; you have "started" your tanks and you are awaiting the delivery of your fingerlings; these are good places to get food:
http://premiumfishfood.com/
http://jimsfish.webs.com/fishfood.htm
Once you are going, you can experiment with different foods. You can grow your own algae, make your own food or even use kitchen scraps. Be slow in scraps you put into your tank to ensure you don't foul the water (eg. oily muffins are bad, bread can be good if used in moderation, raw vegetables can be good). I found tofu to be a welcome food by the fish.
Ongoing and Recipe for your own food:
Purchased bulk food:
A good, reasonably priced food for your grow tanks is Purina Game Chow. This is available locally at Tractor Supply Company. It is variably sized and works well with both my auto feeders.
Tofu:
Tofu can easily be made at home. The most difficult part is making soy milk, but you can do this easily now with "soy milk cookers".
An example of a good maker is here,
SoyJoy Soymilk maker
Once you have made soymilk, you add a coagulant (calcium sulfite, or magnesium chloride) put in a press to remove excess water. You can get food grade ingredients from http://www.soymilkmaker.com/order.html
Further instructions are here,
http://www.soymilkmaker.com/making_tofu.html
Cream of Wheat Cakes:
While I was investigating making my own tofu, and pondering the coagulants used in that process, I began experimenting with alternate recipes. What I settled on and use regularly is the following. It came from the thought of making tofu, but instead uses other readily available ingredients.
1 cup instant Cream of Wheat
1 cup of medium burr ground soy beans
1/2 cup of ground corn meal
1/2 cup of finely cut dry seaweed
Begin making the instant cream of wheat per the package instructions. Immediately after pouring in the cream of wheat, also add the ground soy beans, corn meal and dry seaweed. Continuously stir so it remains smooth and does not burn. Once the mixture begins to thicken turn off heat and cool for about 10 minutes (until still able to pour, or scoop). I scoop the mixture into used tofu tubs with a spatula, pressing as I go, and then allow to further cool. Cover with plastic wrap and place in refrigerator. To use, cut rows and columns into block so that you can remove a square column and feed to tilapia.
Automatic feeding:
I use two types of auto feeders. I use smaller units for my 55gal and 110gal tanks, and a larger unit for my 300gal outdoor setup. Both feeders dispense 2-3.5mm circular pellet food (the Purina Fish Chow).
For my indoor tanks I use an Eheim Air Feeder. These provide about a week of capacity and are reliable. I have a complete review here,
Amazon Review
Purchase from Amazon
For my outdoor grow out tank I use a Super-Feeder ASF-1 unit. I have modified my unit with an extra carrier to hold a little more than 1 week of food.
Super-Feeder Fish Feeder
Reference:
http://seagrant.uconn.edu/whatwedo/aquaculture/pdf/ncrac114_tilapia.pdf
Aquaponic Gardening by Sylvia Bernstein