It's been just over 5 years since we started our aquaponics project. In retrospect, I'm glad we did it but I'm not honestly sure of it's value in a sustainable system. These are the challenges I've struggled with over the time we've had the system.
If you are interested in adding an aquaponics system, I'd recommend spending some time on this forum. The people on the list are extremely helpful and have a great sense of humor. Be prepared to disappear into the site for long periods of time. The site is based out of Australia but there are members from all over the world.
Building and running an aquaponics system is an adventure. We've had a lot of successes, a few missteps, and a lot of learning along the way.
They seem to be an inexpensive way to build a system, however, they have challenges. The buckling means you need to build a good structure to hold them.
I spent the afternoon in the greenhouse making some changes to our aquaponics system. When we initially setup the system, we put two beds above the others. These beds were dedicated to raising duckweed and are setup to be a constant height of water with no other media in the bed. We have had to clean the beds several times since water comes in directly from the fish tank and then settles out in the bed leaving a lot of fish waste in the bottom of the tank. We also have a fingerling tank that is fed directly from the main fish tank and has similar issues.
The water in our aquaponics system has been warming over the last few weeks as spring finally set in. Every few days I look into the water to see if there is any sign of tilapia fry in the tank and this morning, there were. I madly scrambled around and created a home for them. I made a square out of PVC tubing and elbows so it would float and then put that around a pond plant pot to secure the fry from the big bad adults in the system. So far, I've only found three little ones, but I'll keep watching and adding any more I find into the containment area.
I spent the day in the greenhouse yesterday, cleaning up the aquaponics system. It is amazing to have plants growing lushly in November and finding lots of ripe peppers and tomatoes. They do seem to love the environment in there.
We've taken a number of steps this winter to assure the health of the fish in the system. Now, I must admit, we seldom get this much snow in winter but it certainly makes the point.
In the life of every aquaponics system comes the day to wash media to go in the growbeds. We decided on a two layer approach though we know the layers will become somewhat mixed over time.
Cycling is the process of growing enough bacteria in the aquaponics system to support the life of the system. The fish generate ammonia which must be converted to nitrates,a form of nitrogen the plants can use for growth. Bacteria are responsible for that conversion. The bacteria populate linings of the system as well as the grow media in the grow beds. It takes a few days to a few weeks for this process to happen.
Plumbing an aquaponics system is based on a large number of factors and very few systems have identical plumbing. I will describe what we did and how we came to the decisions we did. Over time, if we find we need to make adjustments we will include those as well.