This summer, twenty little Blue Nile Tilapia were hand delivered to my door. I had given up all hopes of finding a supplier in Canada, and was thrilled when I found one near my home. The fish spent their summer growing out in the greenhouse where our first aquaponic system was made. Once the cooler temperatures of September came around, we relocated them inside to a 100-gallon stock tank (giant water bowls for cows and horses). Here’s the growbed two weeks after seeding.
October 15: The bok choy, kale and basil are already forming secondary leaves. Green onions, celery and romaine lettuce were store bought, cut and stuck right into the growbed. It’s amazing how they will continue to grow and regenerate.
More green onions and celery. Cut and store in the fridge for later use, while the ends sit in shallow water and continue to send new shoots and stalks. These onions were cut just above the elastic and grew back in about 2 weeks. I know, I know, I’m digressing, just wanted to share this lovely arrangement growing on my kitchen table. Back to aquaponics…
You can see water is continually being pumped (coming out of white tube) to fill the growbed. To the left is the bell siphon which automatically drains the water back into the tank once it reaches a certain level (1-inch below the surface). This flood and drain set-up is different than what we had previously done in the greenhouse. A timer is not needed and because the pump is always on, it’s less wear and tear on the pump. Kind of hard to explain without losing everyone, so I’m putting it out there to you readers, that if there is enough interest, we may put together some kind of a workshop where you can see how it’s done, or even build one to take home with you. Lemme know and we’ll see what happens.
October 21: A week later, look how much they’ve grown. You can see towards the back where the black hose of the pump attaches to the white PVC pipe. The boxy black thingy is the digital thermometer to keep the tilapia’s water a toasty 80 degrees.
October 26: So this is when I started noticing that the leaves were not as green as they should be; instead they were a mottled yellow. Everything I looked up indicated that it was low in iron. After more investigation, I realized that the timer which turned the lights on and off, wasn’t turning OFF.
Who knew that plants needed a dark rest period? After turning the lights off for 6 hours a day, these pale green leaves started to darken up.
October 29: New leaves are looking a little greener.
Rainbow chard, assorted herbs, pea shoots and nasturtium is doing great, so are the tomatoes in the back. See how much the green onions have grown?
November 12: We keep raising the lights to accomodate the fast growing vegetables.
November 17: Look how much the tomato plant in the back has grown in five days.
November 25: A lush jungle.
Be sure to test the water often, especially in a new system. I rushed it a bit by putting the fish in before properly giving the tank time to cycle and build up beneficial bacteria. The green sample on the left shows ammonia at quite a dangerous level. After doing a 30% water change, and adding good bacteria from the shrimp tank, the levels were at an acceptable level (yellow mean zero ammonia) within a week. Good bacteria converts ammonia to dangerous nitrites, which then converts into nitrates…harmless to fish, wonderful food for plants.
So what happened to our last remaining prawn?
She was fine up until two days after this photo was taken. She died, after a molt, and had been dead a little too long for us to even want to eat her. I probably couldn’t anyways, we became friends in the end.
Tilapia has been the easiest to raise as they are pretty hardy and can tolerate high stocking densities and fluctuations in water quality. Look at those eyes staring at me. We cannot be friends. I have to remind myself that or there will be no fish on the table.
The fish had grown from tiny little 1-inch fingerlings to between 5-7-inch adults. They will continue to grow till they reach plate size of about 1-2 pounds (cross my fingers). This is definitely a male, that thing sticking out is his uro-gential pore where urine and milt passes through.
This is a female, hard to see in the photo, but she has three openings, one of which is a slit (oviduct) to pass the eggs.
We placed one male and five females in our second tank in hopes that babies will come. The male has claimed this flower pot and will try to entice one of the girls to come and lay her eggs.
For some reason, the male looks nothing like the other females. He’s suppose to be a blue tilapia, but looks white to me. The girls huddle in the corner, not at all interested in following him home.
The rest of the fish in the main tank. Did you know once they reach adult stage, the fish are mainly herbivores? That’s what I read anyways. Here, I’ve got cut up blemished leafy greens from the growbed, which leads me to wonder if they will eat sprouts?
Rather than feeding my fish commercial pellets, I’m trying to grow my own source of fish food. Soaking in water, is some wheatgrass, red clover, and alfalfa seeds. Here’s how to grow your own sprouts from a previous post.
Strain by pouring water out through the lid after soaking.
Rinse and strain twice a day, and four days later, you have jars of sprouts.
Pretty amazing eh? These alfalfa sprouts are rich in protein, carbohydrate and minerals. Good for everyone in the family. The chickens and rabbits also love it, the pig brothers, not so much.
So did they like it? Yes, but the problem is the sprouts clogged up the pump which led to fish gasping for air as the water was no longer moving through the system and getting cleaned. I’m going to try it again, this time with some sort of a rigid screen box to sit the pump in and keep the sprouts out. I’m confident that it’s a good source of food for the fish; what I feed them will ultimately ends up in our bodies.
Screens were placed on top of the tank after we lost one suicide jumper. Towards the right of the above photo, you can see clean water automatically draining back into the tank.
So after we started the second fish tank, we also added a smaller second growbed to go with it. Right: Fluorescents (from the microgreen set up last winter) is hung from the rafters. The height is adjusted using S-hooks and a chain.
The plastic pipe attached to the bottom of the growbed is where the water drains. It’s cut to the level that you want your water to reach just before it drains. The hardware cloth around acts as a barrier to keep the clay pebbles and any debris from clogging up the drain. Hubby holds a 2″ diameter pipe, with several cuts made at the bottom to allow water to flow in. A cap is placed on the other end, this “hood” fits overtop the drain pipe. In other words…what you are looking at is the makings of a bell siphon. Water through vacuum pressure, is sucked up into the bell, and when water fills the growbed, will automatically drain. Confusing I know. But it works.
Washed clay pebbles are added to the new growbed, which is from the bottom of an extra rabbit cage I had lying around.
Bell siphon in action; you can see the water reach just below the growbed medium before it drained. You never want the water level to reach the surface or it will encourage algae growth and get all black and slimy. It will also compete with your veggies for oxygen and nutrients.
November 25: Spinach, rainbow chard and bok choy was planted by sprinkling the seeds directly onto the clay pebbles where they fall into the crevices.
November 27: Two days later and the bok choy have sprouted!
November 29: The bok choy have doubled in size, and the rainbow chard has sprouted.
December 3: Bok choy has secondary leaves, and the spinach is finally starting to sprout.
Our little aqua-urban farm in the 6′ x 8′ room in the basement… growing food year round regardless of season.
(I love my little red mechanic’s stool to carry stuff and roll around on. Goes up and down too!)
Our first harvest and meal from this garden will be in celebration of Slow Food Toronto’s Terre Madre Day: Made From Scratch this weekend, December 8-10, 2012. Visit the facebook page and participate by sharing your stories and recipes of a delicious homemade meal, made from scratch, with no processed food!
For an Update to this post, follow this link.