High Tunnel Aquaponics in Winter

We're entering mid-December and the nighttime lows here in Kansas have been reaching about 15F, well below freezing. The water in the high tunnel aquaponics system has been fluctuating in the 72-80F range, while the air temperature oscillates in the 60-90F range.

The fish haven't been growing much, which is to be expected since blue tilapia grow about 3 times faster at 85F than at 72F. They nevertheless seem very happy and healthy, as you can see in this video:

And here's a peek at the grow bed.  I just finished moving the peppers and transplanting the next generation of lettuce, so it looks a bit scraggly right now.  Should look great in a couple of weeks, though.  The white things in the water on the left are all that remain of some giant bolting heads of lettuce.  I tossed some of the heads in there about a week ago when I was reorganizing, and the little 2" long tilapia in the pool have eaten everything but the tap roots.

Blue tilapia fry are growing fast

Here is some fresh footage of the blue tilapia fry from today:

Late October in the Aquaponics Greenhouse

The lettuce is growing fast, as are the cucumbers and the banana pepper plant. I transplanted some other pepper plants into the tunnel; they're a bit droopy, but should pull through. Interestingly, all of these pepper plants were sowed together outside at the same time. When they came up, I moved the runt inside...and now the runt is far and away the biggest and healthiest. We'll see if its siblings can catch up.

Redecorating to accommodate brooding

I originally designed this high tunnel aquaponics system as a production facility rather than as a brooding system.  This means that I had intended to get all-male fry via Fed Ex every 3 months and to simply grow them out to market size.  That plan was simple: just one big fish tank and one big grow bed.

I have since changed my mind and decided to set up my own hatchery operation to brood my own fry.  A hatchery operation (or, if you prefer not to emphasize h's when they lead off words, "an hatchery operation") has different needs than a pure production system.  These needs can be conveniently met by digging out pools in the grow bed to serve as nurseries, but at a cost of reduced filtration and reduced grow space for plants.

I'm now redesigning my system to accommodate the needs of both a hatchery operation and a production operation.  I can squeeze in a nice hatchery operation if I convert 1/3 of the grow bed into a series of nursery pools, and I've calculated that I can convert 1/3 of the grow bed into fish pools if I decrease the peak density in the main fish tank from 1/2 lb fish per gal down to 1/4 lb fish per gallon. 

Below is a pic of the progress to date. Fry collect in the small pool (aka "fry pool"). When they're about 3" long I'll transfer them to the larger pool (aka "fingerling pool"). After another 2-3 months I'll transfer them to a large pen in the big fish tank for their final growout phase.

So in a nutshell, the cost of adding a small hatchery operation to my existing high tunnel aquaponics system is that I'll only be able to produce about half as many adults.  At that rate, I hope to harvest 200 1.5lb fish every 2-3 months, giving me a total of 1,200-1,800 lbs in annual fish production.  We'll see how it goes...

Female tilapia with her fry

One of the female blue tilapia released a couple hundred fry last night. Here she is with her brood (there's a better-quality version on YouTube if you have trouble seeing the fry):

Found first baby tilapia fry and first baby lettuce today!

Here's the baby lettuce:

And here are the first tilapia fry (about 7-seconds in):

Just planted first aquaponics lettuce of Fall 2011

I cleared out the corn, rearranged a bit, and seeded the whole grow bed with Buttercrunch lettuce.  It looks barren now, but the lettuce seeds will sprout within few days and will quickly turn the floor green.  The sole green you're seeing now is a banana pepper plant.  It was doing well until the last 4 or 5 days, during which time I've kept the door closed in order to warm up the water.  The peppers have started to develop brown spots from the high humidity (I think), but I don't think high humidity bothers lettuce.

I also dug out a 2nd small pool and moved the largemouth bass into it from the 1st small pool (the one closest to the fish tank).  I did this because I didn't want the bass to eat any adventuresome fry that sneak through the fish tank's exit; this way, the 1st pool will serve as a catch basin for any wayward fry.