Updates

I harvested some hatchlings and eggs from their mothers' mouths. Got nearly 100. Some eggs were white and developed fungus after a few days. They were sterile. The other eggs were brown. I've got the hatchlings in a separate tank from the fry from two weeks ago...as Tilapia are okay eating their younger siblings.

After a two week cool spell the temps are climbing. We've got the breeding tank setup and now we're waiting for the water temp to climb to 85 degrees F. The female Tilapia have grown to about 4" in length since Feb. The males are passing 6". There's a really big difference in size.

I've got two tanks operating with fish and two aquariums. One aquarium has a small grow bed on top of it. I'll be planting some veggie seedlings soon. The other tank has minnows. I hear they can grow to 4" in length. That's the experiment. The Tilapia are eating a handful of pellets each day now...the goldfish too. I've a 3rd IBC tank setup with the pump mounted externally and using a 'uniseal' (cool). It has 200 gallons of water cycling through a filter. The polyculture was interesting. The goldfish act like Tilapia (guarded and cautious). However they must have ADD because they couldn't stay still enough. In fact they caused the Tilapia to start feeding in my presence. So, overall a success.

Added three goldfish to Tilapia tank to experiment with polyculture.

Positioned camera to view aquaponics setup. Veggies consist of bush beans, tomatoes, cucumbers, and some lettuce. Tomatoes were rescued from greenhouse as it dropped below freezing for a few nights. There are now sixty goldfish and ten minnows in nearest tank. Added new growbed with constant water flow on left side of large growbed. Tilapia are wintering over and only eat every two to three days. Water temperature is 73 degrees F.. Goldfish tank is 61 degrees F.

Tilapia have arrived! We placed 25 fingerlings into the second tank. They measure 3-4" in length. There are Blue and Nile Tilapia in the mix, male and female.

Moved 200L of water to the second tank from the Goldfish tank. Added 200L of rain water to the Goldfish tank.

Started the heater in the second tank. Garage temp is 50 deg F, water is 58 deg F. I've set the 300W heater to 85 deg F. The purpose of the experiment is to see how well an uninsulated tank will heat up. Not expecting too much here. I've done the BTU and heat loss calcs...a bit gloomy. Meanwhile the 2nd tank is still cycling through the nitrogen cycle.

Added pea gravel and lava rock to reinforce the goldfish habitat. If you look closely you'll see fossilized sharks teeth (Megaladon) and fossilized whale bones I've collected from the Chandler Ridge formation. I could hear the fish saying "stupid sharks, stupid whales". =)

I never observed the goldfish swimming into the 2" PVC pieces. I've added two gallon size pickle jars. I've watched three enter so far and manage to get out. Just experimenting with the habitat. I changed filters so the water should be clear in 24 hours.

Our Aquaculture Experiment

As we started are 2nd year of organic gardening (raised beds) in 2011 we decided it would be nice to raise Tilapia for harvesting. Unfamiliar with how to keep fish alive long enough to grow and eat we started researching backyard aquaculture sites. We decided to start with goldfish. They are inexpensive and I figured we would go through a lot of them. We were limited to a shoestring budget so it has taken most of the year to get to our current point. You will find about 50 fish of various sizes (2" to 6.5") in this tank. The 'regular' looking fish are "Common Goldfish". The fish with long tails are "Comet Goldfish".

The tank you see above is 1000L (264 Gal) in size. We keep the water level to 700L. There is a 264 GPH pump delivering the water to a 1G homemade filter. The water leaves the filter and supplies the 30G platic container full of lava rock and pebbles. As the water level rises to a point 1' above the bottom, a loop-syphon will drain most of the water back to the tank. This introduces considerable amount of oxygen to the tank. Bacteria on the rocks converts the ammonia (waste and uneaten food) to nitrites then to nitrogen. We hope to grow lettuce once I get the lighting worked out. The nitrates provide excellent food for plants.

A second tank with an improved(home made) filter is 'cycling'. This means allowing time to produce bacteria in the grow bed (biofilter) to support the introduction of Tilapia in Feb/Mar 2012.

If you are interested in contacting me, you can email me at "cpp-programmer@sc.rr.com". Mention fish in the subject so I'll stop to read it otherwise it might get deleted with other spam.