Aquaponic Plant Rail System: A Cheap Solution


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A rail system is a planting system in aquaponics where plants are placed in Nutrient rich water through holes in piping or gutting material. 

An aquaponic plant rail system consists of PVC pipes or guttering material in which holes are made to hold the plants. Plants are firstly placed into net cups which are then placed into the nutrient rich water within the pipes.

Aquaponic plants are grown in a soilless medium where nutrient rich water is constantly being fed to the plants. 

The plant rail system when used in an aquaponic system, provides many benefits compared to other plant systems that require a growing medium such as a grow bed.

In this article we are going to explain how to safely drill and space the holes in the a rails which are best suited for aquaponic plants.

Build a successful system with these affordable equipment from amazon, that I’ve tried & tested on my setup.

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How Plants Get the Nutrients they Need?

Aquaponics is the symbiotic relationship between plants and fishes. The fishes produce waste which contains ammonia. The ammonia is converted into nitrites and then nitrates in a two step process called nitrification. This is done by nitrifying bacteria Nitrosomonas and Nitrobacter.

The nitrates from this process is abundantly available in aquaponics and is used by plants to produce green leafy branches. For this reason lettuces, pak-choi, cabbages and other leafy vegetables are best suited for aquaponics. 

An added benefit is that the plants get oxygen not only from the water but also from the air since some of the roots are suspended above the water.

Can a Plant Rail System be used in Aquaponics?

A plant rail system can be used in an aquaponic system. The rails can either be flooded or made to be free flowing, where the water drains out. (NFT system). 

Rails usually come in 20 ft length and can be extended by adding another length or can be shortened depending on the spacing requirements of your system. 

NFT Aquaponic system

The NFT rails are usually made from a guttering type material which has a rectangular shape. This rectangular shape helps the plants to sit leveled on the planting holes. 

In an NFT system the rails are placed so that they are slightly tilted. The tilted arrangement allows nutrient rich water to flow from one end of the pipe over the roots of the plants to the other end of the rail where it exits. 

In a flooded rail system, the rails are made from cylindrical pvc piping. The best size of pipes for this type of system is a 3” or 4” diameter PVC pipe. 

Just like the NFT system the pipes are arranged such that they can be lengthened greater than 20ft or cut to suit the size of you aquaponic system. 

Holes are also drilled on the pipes for the next cups and plants to be placed. In this type of piping rail the holes are subjected to the curvature of the pipe which sometimes makes it difficult for the net cups to sit leveled on the pipe. 

Both ends of the pipe are blocked using end caps for the water to be held within the pipe. 

The level within the pipe is held by installing an overflow pipe at the end of the rail. 

PVC Plant Rails

Hole Spacing in a Rail System – 8 inches Apart 

A hole spacing for Romaine and butterhead lettuce seedlings require 6 to 8 inches between each plant and the same follows for other green leafy plants. 

Since in a rail system the spacing cannot be changed after the holes are drilled. The general rule of thumb is to drill holes 8 inches apart to facilitate the growth of other greens if you so desire.

And the general outcome from this is savings for you by maximising on the space you have available.

In an aquaponic system you should plant a variety of leafy greens which includes lettuce, cabbage, pak-choi and broccoli to supplement your home garden. 

Spacing requirements for each of these plants may be different in the soil but in a rail system they all can fit pretty well with a spacing of 8” apart.

How to Cut the Holes in a Planting Rail?

The size of the bit should be the size of the net cups you plan to have plants grow into. Therefore, if you plan to go with a 2” net cup, a 2” bore bit will work just fine. 

I recommend using a 2” netcup since it maximises on space allowing you to grow as many plants as possible within a small space.

The holes on the rails are cut using a drill and a bore bit. 

  • Before drilling be sure to mark the spacing of each hole in a straight line on top of the pipe or rectangular guttering.
  • This is done by firstly making a straight longitudinal line along the length of the piping.
  • Then using a measuring tape make the 9” spacing for each plant.
  • A 9” spacing mark is made because since we’re using a 8” spacing with a 2” netcup the extra inch (8+1) which makes the 9 inches would cover the netcup’s footprint while keeping the spacing between the plants at 8” apart.

A standard drill can be used. 

Pro Tip – 

When drilling the holes start with the drill in reverse. By having the drill in reverse it cuts a neat groove in the PVC pipe or plant rail and makes a guide for the bit. 

(This prevents the bit from becoming stuck and you from turning with the force of the drill)

Now, switch the drill to forward and drill through the pipe with the bit.

The size of the bit should be the size of the net cups you plan to have plants grow into. Therefore, if you plan to go with a 2” net cup, a 2” bore bit will work just fine. 

I recommend using a 2” net cup since it maximizes on space allowing you to grow as many plants as possible within a small space.

Rail typeProsCons
PVC 4″ railCan hold water when pump stopsnet cups does not sit sturdy
Easily availableThe overflow pipe can get clogged with roots
NFT GutteringLess water is requiredDoes not hold water if the pump stops
Plants sits sturdy on top the rail
PVC pipe Vs NFT Rails
https://youtu.be/W7wqpR8IiFc

JayLea

JayLea has a passion for plants and has been gardening since 2015. He has valuable knowledge about gardening and houseplant care and can answer everyday practical questions that every plant owner has.

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