Backyard Aquaponics
A place to discuss aquaponics

I plan on using Mozambique tilapia for my aquaponics system as they are readily available here in Botswana. My question is about feeding them. I know for raising a marketable size fish in six months feeding them with a protein content around 35% is needed however with the great filtering system aquaponics provides is a cheaper source of food possible such as dogfood which is about 18% protein. Would this just create too much waste? Would the fish still grow fast? Also i'm sure root crops such as carrots and potatoes are difficult to grow in a medium of gravel. Would sand be too dense for filtering the water back into the system. I am a missionary here in Botswana and plan on incorperating aquaponics for a soon to be opened orphanage any help would be great blessing.

Hello,

Root crops grow just fine in rock, many of us have done it. No need for the potential issues that can come up by using sand.

As for the Tilapia, Chappo is your man! I think he will tell you what I have proven to be true here with my fish.. Start them off with a high protein (40-50%) early on. They will grow on anything (almost) however, if you don't start them off with good high protien in the early stages, it will take them much much longer to finish out. I have several groups going now, some that are over a year, some 6-8 months, and thousands that are much younger. The youngest ones are the fastest growing by far, since I tried feeding them the higher protein from the earliest stage. This gives the a real and lasting kick start.

Did I say it all just right Chappo?

Mathew

I have used cheap fish food (meant for use in natural farm ponds) and I found it contributed to poor water quality in a recirculating system like Aquaponics.

As noted, it is possible to grow tilapia on cheaper food or even veggies, they will not grow out fast that way. You might be able to manage by feeding high protein starter food when young and then go to other feed for later growth but the poorer the feed, the slower they will grow.

To get them to grow faster, definitely getting all male or keeping them in cages seems to help as breeding tends to distract them from eating and growing. The males definitely grow faster than the females and when holding a brood of eggs, the females don't eat at all and therefore are not growing.

Hi. Dogfood may not satisfy the nutritional requirements of fish. While you may have cheap indigenous vegetable feed stuff available, try to maintain the required protein level by adding fish meal or any good quality animal protein that may be available to you. Protein is a key factor to fast growth. Then you can supplement with Moringa and duckweed as Chappo suggests. Cheerz.

I was alternating flake and dog food for a month or two. Then quit feeding the dry pellets because it was making my water have a brown tint. It was some of the higher end dog food. The ingredients were all good but I didn't want a brown tint.

My tilapia source told me to start them on dry kitten food. I guess it is simply easily available here and is high protein.

ROFLMAO ,, they'll turn into catfish.
Seriously,,,that is a bloody expensive way to feed fish.

Surely a country that can "put a man on the moon" can make hi-protein fish food

What is wrong with catfish?!

Chappo, you are 100% right, but for home use a lot of folks are only raising <100 fish and a 25kg bag of official food is overkill when you can simply spend a few bucks and get 2kg. Far more expensive per kg, but far cheaper if one accounts for what one tosses when it gets old.

Kitten food will have the vitamins etc suitable for a baby CAT.
Fish food will have the necessary additives to suit FISH.

Either way ,, up to you:)

you may use Black Soldier Fly for feeding your fish,.i guess its high in protein content

You can use BSF... and other things... to supplement your feed for your fish...

They're not complete feeds though... and that's the point that Chappo is making...

BSF... for instance .. is high in protein... but also very high in fat content... indeed a lot of aquaculture people that have been using them... are now rendering them first...

meow.

Have you considered earth worms for part of their protein diet? They also provide omega-3.
Worms need a lot of Omega-3 to develop and, in contrast to humans and other mammals, they can convert Omega-6 to Omega-3, using the fatty acid desaturase fat-1.
http://www.innovations-report.de/html/b ... 15163.html

Some of my research notes suggest alternative feeds as well.
The review concludes that about 75% of dietary fish oil can be substituted with alternative lipid sources, such as vegetable oils and animal fats, without significantly affecting growth performance, feed efficiency and intake for almost all finfish species studied. However, as different species responds differently to fish oil diet replacement, further research is required for the realization of eco-friendly and cost effective aquafeeds.

I would also suggest bug zappers or night lights, close to the water's surface, to lure free protein feed for your fish or growing maggots, as has been already suggested.
I would not recommend dog food as there are additives in the feed and the sources which make up the feed are also questionable as well as the potential of an off-flavor to the fish meat from such a diet.

In regards to sand, it has been used before for AP systems with mixed results. There are issues with clogging and difficulty in cleaning the sand afterwards, compaction even with a coarser grade, and "lifting"- sand that floats with the water, leaving the grow beds and damaging pumps or settling where it is not wanted. Gravel oxygenates the water 25% more than a sand bed and that alone is a reason not to use it. Perhaps you can compromise with a very small gravel size that won't clog, compact from long term use, yet heavy enough to remain in place and use worms to keep clogging to a minimum.

Angie ,, those FREE bugs are not really free ,, I would guess a small bug-zapper would cost a dollar or two a week to run.Also remember the bugs that are failing down have been ZAPPED , most of the goodness will be splattered all over the zapper or incinerated not in the bit that drops into the pond/tank.
BSF , worms , Moringa , duck-weed ,, maggots,, cochroaches , silk worms and near any bugs are good additions to the diet. But remember they should be used as additions. Put simply we do not know the effect of feeding a fish ONLY worms or ONLY maggots , balanced diet is the key and fish pellet manufacturers have spent 10's of millions of dollars researching that exact thing,,, so I say the majority of feed should be from those producers. I also agree we need tgo support those manufacturers to replace as much as possible of their product with non trash fish oil.