Small-Scale Aquaponics Patio System Build

Small-Scale Aquaponics Patio System Build

Having no yard to grow our own vegetables living in an apartment, it was tough to accept having to buy vegetables at the market. Therefore, we committed to building a small-scale aquaponics installation around a 55-gallon tank destined for our patio. Small-scale aquaponics systems you can buy online will not satisfy our needs. They are either too small to grow a substantial amount of food or pragmatic DIY constructions lacking aesthetics. We didn’t want to add that motley collection. We wanted it to be presentable as well as durable.

Good Aesthetics Starts with Wood Selection

With these considerations, we opted to use select pine appearance boards which are smooth to the touch and are easy to work. The pine serves as both the framework around the tank and material for the grow bed. To match other outdoor furniture, we stained all the pine with blue Minwax water based wood stain and coated it with Minwax polycrylic finish. Construction of the tank framework and grow bed only took about six hours. What took lots of time was applying the stain and finish. This process lasted a week to apply several coats of stain, finish and waited for each application to dry.

Small-Scale Aquaponics System Construction

Rather than use water proof paint in the grow bed, we used 6 mil vizqueen as liner. The liner could easily be replaced when necessary without having to worry about water leaks or seepage into the wood. We drilled a hole in the middle of the grow bed to install a bell siphon, a truly amazing, yet simple technology critical for flood and drain aquaponic systems.

The bell siphon is constructed using PVC reducers combining a 3 in. x 2 in. PVC reducing coupling to a 2 in. x 3/4 in. PVC Schedule 40 reducer bushing which is connected to the 3/4 PVC Schedule 40 drainage pipe that flows back into the fish tank. The “bell” part of the siphon is cut from a piece of 4 in. x 10 ft. PVC Sch. 40 plain end pipe and a 4 in. PVC sewer and drain cap. More on bell siphons in a future post.

At the heart of the aquaponic system is a pump that lifts water from fish tank to grow bed. We chose a 400 GPH submersible pump from Amazon. All of the plumbing to connect the pump to the grow bed and used as irrigation was constructed using schedule 40 PVC 3/4 pipe.

Testing Out the Small-Scale Aquaponics System

So how does all this work? As water is pumped into the grow bed, it raises the water level to the point where it begins to trickle down the drain pipe within the bell siphon. As the trickle builds down the pipe, a vacuum is formed within the bell siphon which triggers a full powerful drain which empties the grow bed faster than the pump can fill it with water.

The siphon vacuum is broken when there is no water left to drain, air enters through the bottom of the siphon and the grow bed begins to fill again. This allows the grow bed to drain at regular intervals which is the purpose of a flood and drain system.

Lighting and Containers

Since this would be on a covered patio, we needed to install lighting over the grow bed. We used 12W LED replacements for T8 fluorescents from Home Depot since we wanted to reuse the T8 housing we already had. We also purchased 16 square plastic (5.5×5.5x6in) hydroponic pots for the grow bed from Hydrofarm. More updates soon!

Aquaponic Grow Bed Setup for Patio System

Aquaponic Grow Bed Setup for Patio System

We’ve completed the basic structure of our Patio Aquaponics System. Our next step is to prepare and complete the aquaponic grow bed setup to properly test the water pump, plumbing, irrigation system and bell siphon to ensure a reliable flood and drain action.

Lining, Bell Siphon and Containers

As you may have read in our post detailing construction of the system, we’ve already lined the grow bed with 6 mil thick vizqueen — we also installed a custom-made bell siphon. For containers, we purchased Hydrofarm’s half gallon Vega Square Pots which measure 5.5×5.5x6in. This size allowed us to put 16 pots snugly in our grow bed.

Why Square Hydropnic Pots?

We went for a square-shaped pot to maximize the amount of hydroton we could load into the grow bed which provides more surface area for beneficial bacteria to reside to process the fish waste into nitrates and nitrite (plant food). So to fill about 8 gallons of net pot, we needed to purchase a 50 L bag of hydroton which provided more than needed.

Aquaponic Grow Bed Irrigation

After placing our hydroton filled pots, we installed the irrigation system made using 3/4 schedule 40 PVC piping in which we drilled 1/8 sized holes so water would be deposited into each of the pots. We wanted to spread water distribution equally to all the 16 pots in an attempt to equally spread solid waste since water was directly being pumped from the fish tank. The intent is for the hydroton-filled pots to also serve as solids filters, especially since we are going add red wiggler worms to the setup later to process the solids trapped in the hydroton.

Aquaponic Grow Bed Plumbing Test

We filled our 55-gallon fish tank with water and started up the 400 GPH hydroponic pump we purchased at Amazon. As expected, there were several leaks at the joints where we installed either elbows or t-joints so we sealed using plumbing tape. We chose to use tape vs PVC teflon sealant since we may want to disassemble the plumbing as we improve the system. Great news, it all worked! The 400 GPH provides a heavy flow so it took about two-three minutes for the grow bed to fill. The bell-siphon then took about a minute and half to drain the grow bed empty. Our next step is to purchase and introduce fish to the system to begin cycling the water.