We are using a submersible pump, and a flexible anti-kink hose to run water up to the growbed. We start by sitting the pump on the ground next to the system, this allows us to measure the length of flexible hose we will need to reach up to the growbed.
Be sure to allow a little extra length in the pipe so that you can access it and move it around with ease. I won’t go into too much detail about how to attach your pipe to your pump because every pump is different, here you will have to find the right fittings for your pump and pipe. Your pump size may vary depending on what you have available locally or also depending on your long term plans. If you are thinking of expanding your system at some stage it’s probably better to get a slightly larger pump now rather than having to replace it down the track. The pump we are using in this system is 3000L/h probably a little over kill, but this will allow some expansion. You want to have at least 1000L/h for a system of this size.
The pipe then comes up to the growbed, on the growbed we like to irrigate the water around the edge of the bed, this allows any solids to be distributed around the beds. So we have 4 pieces of pipe cut to size to fit around the bed, along with a T piece and barbed fitting that will fit the anti kink hose. The pipe work around the top edge of the growbed has 6mm holes drilled in the underside of it, spaced around 150-20cm apart. This means that the water is sent straight down into the media, you don’t want water splashing on the surface of the media if you can help it, this will grow algae over the surface of the media.
Pretty much done now. You can run this either as a constantly flooded system, or you can put a timer on the pump and run it as a flood and drain system. If possible try to get some water from an established aquaponic system, or perhaps from a friend with an aquarium or a pond, this water will contain the beneficial bacteria to help get your system cycled quickly.