Aquaponics and Hydroponics- are both methods of crop cultivation that are soil free. The main difference between them is that aquaponics incorporates a hydroponic environment along with aquaculture, which is cultivating fish. Aquaponics is a combination of aquaculture with hydroponics so that a balanced ecosystem is created which benefits both, the fish as well as the crops.
An aquaponics system consists of:
One hydroponic bed which is used to grow crops using the fish water nutrient solution.
An aquarium or a tank where the fish are grown.
These two components coexist, and they are codependent on each other for their growth. With the growth of fish, the aquarium is filled with their excreta and other waste material. The operator needs to change this water at regular intervals so that the fish live in clean water to flourish. Conventionally, if you only cultivate fish, you would dispose this water, which is a complete wastage of a valuable natural resource. Fish excreta are a precious plant nutrient.
In Aquaponics the fish waste feeds the plants and the plants filter and clean the water for the fish. For hundreds of years people have used lake water as a nutrient mix and they have also used creek water. The current favorite is to use fish tank water. There are a few great reasons for this. One is the fish need the water to be chemical free to live well. Two, the fish waste is a perfect fertilizer for plants. So, using the water from an established fish tank will work well for growing plants. Make sure you are not using water from a polluted fish tank, lake or river. Look for signs of high levels of fish deaths in the water and on the banks. This is a dead give away that the polluted water will not do your grow system any good.
And that is precisely the hidden time bomb with Aquaponics, this is not a simple, easy system to keep in balance. You must daily check the water pH and ammonia levels to protect the fish and you must check the nutrient levels in the water to protect the plants and promote their growth, and you must remember to feed the fish the correct amount of food each day to promote their growth. If you put in too much fish food it will rot and pollute the water and you will lose the fish and then the plants will die.
What do you do if you check your system one midday and all the fish look sick? – They were alright at the morning check. You have maybe just a few minutes to a few hours to correct the problem before you lose them all. You can’t just pour fish medicines into the water because that will damage or kill the plants. What do you do????
What do you do if you check one day and all the plants look sick? You can’t just add fertilizer or other chemicals – because that will kill the fish. You also can not use any kind of insect spray on the plants as that will damage or kill the fish. What about that county truck that came around last night spraying for mosquitoes, Did the spray cause your system to crash???? What about that several hours power failure two days ago – when your circulating and air pumps stopped? How about the hard rain this week that changed your systems water and pH levels? Did any or all of those cause today’s die off? You are about to lose everything – your money investment and probably several months of your time and labor.
The big boys on the large commercial Aquaponic farms have very expensive ($10,000 and up) computerized testers and analyzers that continuously check their systems 24 hours 7 days a week. Those analyzers then control automatic chemical injectors to make sure their systems stay in perfect balance. The really big big boys on the Aquaponic or hydroponic mega-farms have complete in house testing laboratories staffed with several bio-technicians and a couple of biology PHDs to protect their investment and make sure everything stays in balance. There is no substitute for cubic money….
If you still want to try Aquaponics growing read on, then go look at the BEST GURU section that describes the simple KRATKY method.
The system of Aquaponics can use the wastage of the aquarium only after it is treated with organic bacteria. This treatment converts the excreta of fish into nutrients which can be used by the plants being grown in hydroponics section. In hydroponics, the plants make use of nutrients in water while they grow. With time, this water must be exchanged with fresh nutrient solution to allow the plants to grow at a normal pace.
If you get nutrient lockout, your plants will not take in nutrients anymore. If you are using fish water you do not have to worry about this. Mother nature has made it easy. The fish make the water just right for the plants. If you are using a newer fish tank you may see higher levels of ammonia in the water. Any fish tank should have an ammonia tester with it, many plants and the fish will not tolerate a high level of ammonia.
Expenditure on chemical nutrients:
In hydroponics, the chemical nutrients can turn out to be expensive because you have to buy the nutrient solutions every time. Moreover, these costs are rising because of scarcity and over mining (some of the growing media are mined material). On the other hand, in Aquaponics, you can use fish feed in place of expensive nutrient solutions. The cost is much less and also gives you better support for your plants.
The sterile environment of hydroponics is entirely man-made, while it is a natural ecosystem in Aquaponics, which makes it an absolutely organic system. The hydroponic system uses expensive nutrient solutions made of salts and chemical mixtures to feed the plants. Aquaponics uses plant food which is fish waste treated with composting worms and organic bacteria. The disease rates are lower in Aquaponics and plant growth is much better.
Before venturing too far into the Aquaponics setup, let’s take a second to go over the basic chemistry.
Fish release ammonia as a waste product. It comes from their gills and fish poop. In a closed system, if it’s not removed, this ammonia will build to toxic levels. And the more fish you have, the faster this build up occurs. In order for aquaponics systems to work, the water pumps need to run several times per day and an aeration system must be constantly running to provide the fish with oxygen.
The key to aquaponics is the natural bacteria found in the growing bed and the biofilter. The bacteria eat ammonia and turn it into nitrates, which are great food for plants. Without these nitrifying bacteria, the fish would die in their own waste and without the nitrates, the plants wouldn’t have anything to eat.
Aquaponics puts this natural “toxicity” to good use. It turns the ammonia into plant food using two types of bacteria. The first bacteria (Nitrosomonas) consumes ammonia and releases nitrite. Following that, a second bacteria (Nitrobacteria) converts the nitrite to nitrate. Finally, plants use the nitrates as their primary nutrient. Several studies have shown that after the Aquaponics biofilter gets established, which takes 6 months minimum for the bacteria colony to fully develop and stabilize; it yields faster, more efficient and better plant growth in comparison with regular chemical fertilized hydroponics. This process cleans the water and keeps it healthy for the fish.
Aquaponics Pros and Cons:
Water Friendly: The same water is reused. Only a little bit of water needs to be periodically added to account for evaporation. Since no water is lost through soil, it only requires about 10% of the water used in traditional farming.
No Chemical Fertilizers Necessary: You don’t need any chemical fertilizers to grow food because the fish produce the plant food.
Organic: It is organic by default because any herbicides or pesticides would harm the fish.
No Back-Breaking Labor: Systems are usually set up at waist height, which means no need to bend over.
Fast and Efficient Food Production Method: Once the system has been started, you can harvest food in an aquaponics garden very quickly.
No Weeds: In an outdoor system, weeds might appear – but these can easily be plucked out of the growing medium.
Healthy Food: In addition to growing plants for food, you also get fish (a great source of Omega 3). There is nothing like the feeling of self-sufficiency that comes with producing your own food!
Year Round Operation: It is possible to do seasonal aquaponics. However, it takes time to develop the biofilter. To be effective, aquaponic systems must be run year round – which means no break for you!
Requires Electricity: You need power to run the pumps. Power outages can destroy your entire system in only a few hours! You might want to consider a solar system as a backup.
Fish need to be fed several times daily: You have some wiggle room with traditional gardens, wth aquaponics, you don’t want to miss a single fish feeding.
DIY Aquaponics – Supplies Needed:
First, you’ll need a place for keeping your fish. There are a lot of different options for this. A lot of people start out with a large aquarium. Then they scale upwards, they might use things like plastic barrels, old bathtubs, or basins with pond liners in them.
Not everything will work as a fish tank though. Here’s some important things to keep in mind:
No Metal: Metal should never be used in aquaponics systems. The metal is corrosive, which means chemicals can get into your system. The metal will also throw off the pH of the system.
At Least 50 Gallons: It is possible to make an aquaponics system with a smaller tank. However, it’s a lot harder to regulate pH and temperatures in small tanks. You also won’t get any edible fish or much edible plants with such a small system.
Choose a Round Tank: The reason round tanks are preferable is because they don’t have “dead zones” – areas where water doesn’t get circulated. Dead zones cause sediment buildup and have less oxygen. If you must use a rectangular tank, then you’ll have to periodically stir the water in it.
Lots of things can be used for a grow bed. Usually plastic containers are used. You’ll need the grow bed to be at least 12 inches deep. The size of the grow bed depends on the size of the fish tank (more on that later).
The grow media has numerous important purposes:
Anchors the plants and is home for some of the nitrifying bacteria and worms
Helps regulate temperature
Holds air and water for the plants
The most popular grow media is Hydroton, a type of expanded clay, the original Hydroton brand is a highly recommended top quality clay from Germany. The cheaper option is expanded shale, don’t expect the same quality as Hydroton though.
NOT Recommended grow media:
Sand, pearlite, or vermiculite -will clog system
Soil, peat moss, wood chips – will decompose and alter pH and nutrient levels
Diotamite, Maidenwell and Higrozyme – will lower pH over time
Anything smaller than ½ inch – could clog the system pumps
Anything larger than ¾ inch in diameter – will create too many air pockets,
Setting up the plumbing isn’t just about getting the water circulating. You’ve got to make sure you are circulating enough of the fish water (so ammonia doesn’t buildup in the tank) without circulating too much water into the plant bed (and possibly drowning your plants).
The plumbing parts you will need include: Pumps, Pipes – non-metal, Sealer, Timers, Irrigation system – for distributing the water through the plant bed.
If you’ve ever had an aquarium before, then you know that fish must have their water constantly oxygenated. At oxygen levels of less than 3ppm, fish will become severely stressed. Levels lower than this can cause the fish to die. The easiest solution would be to buy an aeration device for your fish tank. However, this requires constant energy and money. You can also make an oxygenation system as part of your water plumbing. By drilling holes in the pipes, you can cause some of the pumped water to spray into the fish tank. The spray naturally aerates the water, and aids your separate aeration device.
If you are fortunate to live in a year-round growing climate and have an outdoors system, then you won’t need any grow lights. However, indoor systems will need bright grow lighting. Even greenhouse systems will often require supplemental lighting. There simply isn’t enough light in the winter for the plants to thrive. And, if your plants aren’t thriving, then they won’t be filtering the water which goes back to your fish! Unfortunately, grow lights can be very expensive to buy and operate. They also produce heat, which could cause your system to overheat. You’ll have to carefully calculate lighting needs when designing your aquaponics garden.
Testing and Maintenance Equipment:
Finally, you are going to need some basic supplies for measuring pH, temperature, ammonia, nitrate levels, and chlorine. Cleaning your system is pretty easy. However, it helps to have some supplies like brushes and a mesh net or colander for cleaning media (it needs to be washed before adding it to your system).