There wasn’t much about the success rate of starting off seedlings in clay pebbles in any of the aquaponics resources I researched, but I thought I would give it a go as transplanting a clay pebble pot straight into an aquaponics grow bed is much less disruptive to the plants than washing soil off the roots and redistributing them in different media.
Whilst I was waiting for my aquaponics system to properly cycle I started off some spinach, pak choi and basil, in the same clay media as my grow bed. I also grew some seeds in soil to monitor the difference. Obviously as the soil has more nutrients after about 10 days the soil plants started to grow much faster, however once in the system the plants in the pebbles were eventually much stronger than the soil plants. I think having all the roots washed and rearranged in pebbles did not leave the plants in a happy mood and in-fact some of the wilted and perished! This did not happen with any of my pebble seedlings.
VERDICT: Start off your seedlings in the same growing media as your system. Plant them in a pot with holes in the bottom so you can pop them straight in your grow bed. Grow them for about two weeks (or until the roots poke out the pot) before putting them in the main bed, and if possible water them with the same water that is in your system BUT only if it is fully cycled.
TIP: A heated seed tray helps development and of course lots of light is beneficial.
My home aquaponic system is a very simple one! It is squeezed into the back of the kitchen right next to the back door and is made up of a surprisingly small number of things. The bottom tank for the fish is a really useful storage box and the grow bed is a shallower storage box that was already around the house. All the plumping bits and fittings were easy to find once I knew what I was looking for.
The basic premise for my system was to have the fish tank on the floor under a very cheap coffee table and the grow bed on top of the table directly draining into the tank from the grow bed via a pipe going straight down through a whole drilled into the table. This set up so far is running quite nicely but not without a few hiccups along the way. Like Alice, I started with a bell siphon to automatically drain the grow bed when it flooded but the siphon I had made just wasn’t reliable enough so I went for the pump on a timer method. (More on siphons, pumps, timers and standpipes on a later blog post). I had it going for 15 minutes every hour which was way too much flooding! Due to this and some over eager cats trampling my plants as well as some issues with mould I’ve had to pull out my plants and a have a bit of a rethink and a refresh. This system is so small I’m not sure I’ve got the balance quite right yet. To protect my little fishes since their grow bed filter is no longer running, I’ve got the hose pipe that initially flooded the grow bed going through a DIY sponge filter to keep the bacteria colony I worked so hard to cultivate going and converting ammonia into nitrates (more on the nitrogen cycle at a later date). So far my water levels are all stable.
I plan to start some more seedlings and when they are strong enough transplant them into the grow bed to get the system running as it should. I’m very hopeful!
This post is a brief overview of my mini home aquaponic system and how it runs on a day-to-day basis. Setting up this home system is a precursor to a larger set-up we are making and a way of learning the principals of aquaponics and how to establish the nitrification cycle in a recirculating aquatic environment.
The system is a basic flood and drain model which originally had a bell siphon to automatically drain the bed. However I have since modified it to just a small stand pipe as the roots of my plants have reached the bottom of the bed and now it only needs to flood a small amount. At the moment the pump is on a timer and set to run for 15 minutes, 5 times a day.
The video below is the system prior to beginning any growing and before I had cycled my system ready for the fish. It has a small indoor fish tank pump transporting water to the grow bed via a hose attached to a PVC pipe. This delivers water in 3 places and the water is then returned to the tank via a bell siphon which creates a vacuum and completely drains the bed once it reaches the height of the stand pipe:
And this video is after everything is up and running, with 2 goldfish and a range of plants including aubergines, basil, spinach and pak choi:
So far the the system is running successfully but the winter light has meant growth slowed significantly so I have since installed a grow light. I also accidentally overwatered the system with my original bell siphon set up and unfortunately lost the spinach plants. I think this is easy to do given the size of the system and I am hoping it will not be a problem with the larger setup we are building.
More posts to follow on Jasmin’s home system, and instructions on how to build various parts on the aquaponics system.