From aquaedu@shore1.intercom.netWed Sep 13 11:02:43 1995 Date: Wed, 13 Sep 1995 10:23:24 -0400 From: aquaedu@shore1.intercom.net Reply to: hydro@Hawg.Stanford.EDU To: hydro@Hawg.Stanford.EDU Subject: Re: aquaponics What is AQUAPONICS? 1. Aquaponics is a semi-closed loop ecosystem. 2. Aquaponics is a combination of aquaculture (raising fish in a controlled environment) and hydroponics (growing plants without soil, providing the nutrients to the plants mixed into the water fed to the plants). 3. Aquaponics is a manmade version of Mother Nature's pond, stream, and field ecosystem. In an aquaponic system, you feed the fish, the fish wastes feed bacteria, the bacteria wastes feed the plants, and the plants clean the water for the fish. Fish live in their own bathroom. They can't help it, they have nowhere else to go. And fish waste is mainly ammonia nitrogen, that evil smelling stuff you clean windows with. If you feed the fish too much, and their ammonia laden wastes build up, the fish do the same thing that you would do if immersed in an ammonia bath,... they die. Even if they don't eat the food that you toss in the tank, the natural breakdown of the food will kick the ammonia level through the roof (fishtank?), and poof, dead fish. Luckily, nature provides a way to eliminate this deadly hazard. Good thing for us that it does, or else the world's seas would be big pools of water filled with dead fish long before man crept out of the primordial ooze. Certain bacteria eat ammonia, they LOVE it. They thrive on it, can't live without it. The most voracious ammonia eating bacteria are called Nitro Sommonas bacteria. They gobble the ammonia down, use it to fuel their tiny bodies, and give off wastes full of nitrite nitrogen. Most fish can handle up to 10 times as much nitrites as ammonia. BUT...if the nitrites become to strong, there goes the fish, belly up again. Now, fish have been doing fine for eons. So obviously, something is taking care of the nitrites. Nature always provides a way of taking care of wastes. This time it's another bacteria, Nitro Bacter. These wonderful little beasties feast on nitrites, eat it like we would feast on ice cream on a hot afternoon. And when their bodies are done, they excrete nitrates. NitrAtes are 10-100 times less dangerous to the fish. Still, if the levels of nitrates ever manages to get too high, it can still kill the fish. Luckily, nitrates are the form of nitrogen that plants love to eat. Not just one or two types of plants, nearly all plants love nitrates. From the lowest form of blue/green algae to the tallest Redwood tree, they all use nitrates as their nitrogen source. And, next to Carbon Dioxide, nitrogen is the highest chemical on the plant's food list. Without nitrogen (nitrates), the plant won't grow. Give a plant plenty of nitrogen (along with plenty of light, water, CO2, and about 13 other tinier amount of other elements), and it grows big and strong. It also locks that nitrogen up in it's leaves and stems, removing them from the food chain. When the plant dies, other forms of bacteria (along with bugs, fish, animals, and humans) feast on the plant. Their wastes start the cycle all over again. nitrites>nitrates>plants>animals>ammonia..." An AQUAPONIC system contains all three of the necessary parts of the ammonia/nitrate cycle, fish to produce the ammonia, bacteria to break the ammonia down to nitrates, and plants to feed on the nitrates to create fishfood to start the cycle all over again. In the simplest classroom sized aquaponic system, the fish live in a standard fish tank. A pump that sits in the tank with the fish pumps the water (and fish wastes) up to a series of troughs sitting nested into the top of the tank. As the water sprays out of the pipes leading from the pump, it picks up oxygen, and flows down the troughs. Plastic pots sitting in the troughs contain blocks of rockwool, a sterile growing media similar (in appearance) to fiberglass. The water (and dissolved fish wastes) feeds up into the rockwool by capillary action, where bacteria are cultivated. The bacteria do their thing on the ammonia, and feed plants that are also growing on the rockwool cube. The cleansed water then flows down the trough, and pours into the fish area in the tank, completing the cycle. More complicated (and more efficient) aquaponic systems use the same basic concept, but they are more efficient at gathering the fish wastes, have several types of hydroponic systems to handle separating the fish wastes into suspended verses dissolved solids, more elaborate hydroponic systems for nitrate removal, and perhaps other systems to maximize the growth of bacteria and removal of non-organic materials from the water. They also may contain automatic monitoring systems, backup pump systems, auto feeding systems for the fish, and other systems to maximize the growth of the plants. Aquaponics can be integrated into an indoor pond system to create a beautifully landscaped show system. Picture a mountain lake glimmering in the sun, with fish leaping and breaking its shining surface. Picture a babbling stream with fruit laden trees lining it's banks. Picture a pristine waterfall feeding that stream, with vines trellising down the sparkling rocks that bracket the falling water. Now picture this idyllic scene, in miniature, babbling away in your atrium or a corner of your living room. It's possible, quite possible. A aquaponic system needn't be a geometric conglomeration of plastic troughs and tanks. With a little ingenuity and foresight, you can form an aquaponic system into a work of art. All of the basic ecological processes are still integrated into this miniature mountain glen. The lake can be formed from a preformed ornamental pond. The stream can be formed from properly prepared concrete, with the "fruit laden trees" being bush-type cherry tomatoes and sweet basil. The waterfalls can be formed from a mound of native stone, or easily positioned mock stone blocks, covered with trellising spider plants. And all of the plants can be rooted in rockwool cubes to provide the home for the bacteria that handle the "dirty work". You CAN bring Mother Nature into your home, it just takes a little planning and the right resources. For more information on setting up YOUR own aquaponic system, whether it be a hands-on learning system for students in your school, or a awe-inspiring miniature alpine glen in your private atrium, contact Hydro/Aquatic Technologies. We can help you set up the perfect system of your dreams!