Friday, September 23, 2011

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):

Wednesday, September 21, 2011

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.

Thursday, September 15, 2011

Corn is Tasseling, but...

The corn is tasseling, but I don't expect good ears. The system is extremely nutrient deficient right now, since there is so little fish biomass. The system is designed to handle around 800 lbs of fish, but there's only around 10-15 lb of fish in there right now. So since the fish part is running at about 2% of capacity, and since I'm not adding fertilizer, the plant part is extremely nutrient starved. Since it takes lots and lots of nutrients to make good ears of corn, the ears probably won't develop into anything worth eating.

If you're wondering why I'm not using fertilizer, here's why: the cheap stuff is toxic to aquaponics systems, and an adequate supply of the safe stuff (Maxicrop, aka Seasol) is tremendously expensive for a system as large as mine. I've considered dumping a bunch of phosphoric acid (which would yield phosphates as it decomposed) and nitric acid (which would yield nitrates), but it would still cost a sizable amount for the quantities I'd need. Therefore, I'm choosing to just wait until the fish can do their job. The fish are brooding now, so if there's a good hatch and good survival, the tank should be up to capacity in 4-6 months.

Wednesday, September 14, 2011

Tilapia are brooding

The blue-colored tilapia you see here are females with mouths full of eggs/fry. The mums should spit out the fry in a couple of weeks.

If I had panned around, you'd have seen some algae building up on the pvc and walls (you can actually see a little bit of green on the pvc in the vid). The only reason there's any algae to see is because the females have stopped feeding while they brood. Before they started brooding, the tilapia kept the pvc bone-white and the water sparkling (they LOVE algae, consuming it both by filtering the water and by nibbling on underwater surfaces on which it grows).

The males are significantly longer and are white with blue dorsal fins.  This was surprising to me, since males of most animal species are usually the showy/colorful sex and the females are usually duller and less colored.  Regardless, these white males constantly defend their nests (clean swept patches on the bottom) and try to attract romance (darting up to the school of females and 'flashing' in an attempt to get a lady to follow).  You can see one of them flash near the top of the screen at the 20-second mark in the video below, and another at the 34-second mark.

Most of these tilapia are probably 7-9" long right now.  They were only 1" long when they arrived about 3 months ago (June 2nd).