DIY Hobby Aquaponics System

diy hobby aquaponics system

DIY Hobby Aquaponics System

Home Building A Low Maintenance System for Fish & Plants, How To Step By Step.

There’s a lot of ways you can build your own DIY hobby aquaponics system with success, ie there is no one “right” way to build a DIY hobby aquaponics system. However, there ARE some basic elements that you should follow and incorporate into your own aquaponics project to keep both fish and plants healthy and happy.

aquaponics system media

[quote]Aquaponics is fun, easy and productive—that is when adhering to just a few basic rules and principles that we will list here. Keep these at the front of your mind when designing or building your own home hobby aquaponics systems[/quote]

After nearly 5 years of continued success in our DIY Vertical Aquaponics System, it’s time to change things up—besides, we needed the greenhouse floor space for some new growing projects like our Rolling Bench Drip Trays.

Follow along, as we show step by step how we built a 50 gallon capacity system capable of supporting a dozen large healthy aquaponics friendly fish like Tilapia and growing a variety of plants, including heavier feeders like tomatoes.

aquaponics system tilapia

We can say with certainty and confidence that Aquaponics is fun, easy and productive—that is when adhering to just a few basic rules and principles that we will list here. Keep these at the front of your mind when designing or building your own home hobby aquaponics systems. We recommend you review and understand the Pillars we have listed before getting started in the Step By Step (Below Pillars Section) details we provide here.

Pillars of Aquaponics Success

Temperature

Super important. Make sure that the system you build will be able to maintain the right temperature range for both your plant and fish type.

For example, Trout prefer colder temperatures, ie BELOW 65 Deg F, so spinach, kale or lettuce might be a good choice here. Tilapia thrive in warmer temperatures, ie ABOVE 65 Deg F, so Basil and or tomatoes could be a better choice.

In most situations in North America, fish tank water heaters will be required to keep tank temperatures above 65 Deg F during winter months. Further, in a lot of regions even with a heater, keeping a tank for warm loving fish outdoors in winter months may not be feasible or practical. A greenhouse is an excellent year round option, as are indoor gardens where year round fish production is desired.

Bio Filter Media or Bed

Without a proper media bed or bio filter, the water that the fish live in can become toxic to the fish living in it over time due to a build up of fish wastes, organic residue from fish feedings or plant based debris, etc.


The health of your DIY hobby aquaponics system is largely dependent on the beneficial microbes that will convert nitrite, ammonia, etc (stuff that is toxic to fish, and plants in system cannot absorb by the roots) to Nitrate (NO3) and Ammonium (NH4)—the forms of Nitrogen plants take up to grow, while “cleaning” the fish tank water.


These beneficial microbes are not swimmers, they need a solid media or surface to live on while purifying the fish water, ie converting toxic forms of nitrogen (nitrite, ammonia) to forms of nitrogen your plants take up as fertilizer.

This is what the gravel and filter do in common aquarium set-ups, the difference being here with a DIY hobby aquaponics system, is that the plants will take up what is normally captured and thrown away.

Choose your media carefully. Regular pea gravel can be OK, although sometimes it can leech unwanted substances or alkalinity into the fish water. Do a quick search online about how to test media suitability for use in aquaponics. Further, pea gravel can be very heavy in quantity, especially when holding water so it would need lots of support. Grow rocks are usually ideal for both fish and plants living in the system and are usually much lighter than gravel.

Additionally, the media bed is where your worms will live! Yes, that’s right—these guys are very efficient at breaking down organic sludge that accumulates, and converting it to friendly substances for your plants like Carbonic Acid (besides preventing the system from eventually clogging up with organic sludge)

Water Quality

In our DIY hobby aquaponics system, we use tap water ONLY if it has been filtered through a de-chlorinator and sediment filter first. Chlorine is extremely harmful to the health of plants and fish in an aquaponics system because it is added into water to kill off microbes—the very organisms we are counting on, as described above in Bio Filter section.

The TALL BOY Filter is perfect for our needs, especially with the KDF activated carbon intended for removing not only chlorine, but also Chloramines which cannot be evaporated or stirred out of water. Because it has a great flow rate, we also use it for watering or organic outdoor garden beds—just hook up the filter to your hose spigot.

*Special Note* WE DO NOT USE RO WATER OR RAIN WATER IN AQUAPONICS. There is no “hardness” to these water sources (ie Calcium and Magnesium), so they are unstable for pH levels—a system pH crash could lead to serious problems like crop failure or even the death of your fish if left unchecked. This is partly why we add the Limestone Chunk (1-3 LBs per 100 gallons, usually).


SPECIAL THANKS TO AquaTechPondCare.ca for their expertise in pond water quality–want to know more? Ask these them!


Fish to Water to Plants Balance

Tilapia have been farmed by people going as far back as Biblical times. This fish variety will do well in high densities and don’t need the cleanest water, so they are well suited to a DIY hobby aquaponics system. We’ve heard of densities as high as only one gallon of tank water per adult tilapia fish, but that’s not pleasant for the fish or even necessary here. A dozen full grown Tilapia in a near full 55 gallon food grade plastic drum is a good balance. If you are using fish other than tilapia, do some research first—you’re better off to go too low than you are too high when it comes to fish densities per gallon if tank capacity.

Some plant types are heavier feeders than others. When sizing up planting media bed area relative to fish tank capacity, our experience has shown that 16 square feet of growing bed is a nice balance for hungrier feeding plants, for example herbs and tomatoes, per 55 gallon poly food drum. Naturally, things like the depth of the bed and the type of aggregate will play a role here too. There’s no exact formula, just basic rules of thumb.

Fish Diet

The number one mistake most folks new to a DIY hobby aquaponics system will make is overfeeding their fish. Some types of fish are very sensitive to what you feed them, while Tilapia are more like toothless piranha, eating just about anything they are able.

VERY IMPORTANTLY, what you feed your fish and how often has a direct influence on the amount of nutrients that will be ultimately available to support healthy plant growth—and it ALSO has an influence on the potential for things like nitrites and ammonia to reach toxic levels in the system. A good go-to food for Tilapia is warm water pond pellets, however, we’ve had success with everything from organic breakfast cereals to crushed up dog kibble.

If there is food left in the water after 2-3 minutes from when you added it, there’s a good bet you are overfeeding. Tilapia do not typically need to be fed every day either, they re-feed on organic matter floating in the water.

Other types of fish may require more care and thought as far as diet and feeding frequency, so it’s worth researching your choice further.

How To, Step By Step, DIY Hobby Aquaponics System Build

Step 1

Materials

Food grade plastics or pond liners for fish tank and beds, potable water tubing for plumbing, fittings and adhesive.

We used a well cleaned food grade 55 gallon polyethylene drum for the fish tank and hydroponic system modules for the growing beds (Under Current 8 gallon modules with spin-tight connection fittings).

barrel for aquaponics tank

Above: It’s what’s INSIDE that counts!

Our grow modules/filter beds are supported by concrete building blocks and cedar lumber.

We had a surplus of LECA (clay pebbles) and Growstones for use as bio filter media/grow beds in our DIY hobby aquaponics system.

Flood or drip trays may also be suitable as your combined bio-filter/grow-bed. NOTE if you want to try NFT (no media) it is possible with the addition of a separate bio-filter in the loop, however, this is best reserved for more advanced aquaponics enthusiasts.

Small mag-drive type submersible pump suitable for aquariums and ponds (model 2 mag drive here). Submersible versus external helps ensure fewer chances of leaks that can drain (and wipe out) the system.

1-3 lbs of solid or compressed limestone for every 100 gallons of tank capacity (for pH stability, available from pond suppliers)

150 watt to 350 watt aquarium heater (see manufacturer’s recommendations based on your tank capacity and temperature lift required)

Water Filter for removing chlorine, chloramines and sediment when adding tap water to the tank—or at the very least a fresh water aquarium dechlorination kit of suitable capacity.

Floating aquarium thermometer.

Additional Note on Materials:

-1/2” to 3/4” PVC diameter, polyethylene or ABS pipe and fittings are a good size for this scale of DIY hobby aquaponics system for fill/delivery pipe, and you’ll want at least 1-1/2” diameter pipe for drainage (we used 2” diameter spin-tight fittings from CCH2O.com)

-use Low VOC PVC/ABS adhesive and natural silicone caulk (make sure it says safe for aquariums)

-a jigsaw is very handy for cutting openings, drill for piloting holes for jigsaw blade (or use a hole saw)

-be careful sourcing barrels; smell and touch inside, noting that blue barrels are usually used for food (BUT NOT ALWAYS)

-permanent marker and measuring tape

Step 2

Prepare the barrel.

Scrub the inside the new or used barrel and lid with a mild bleach solution, rinsing very well after with fresh clean water.

Will you stand the barrel up (tall) or lay it down sideways to conserve height?

If sideways, you will need to partially fill and leak test. This barrel had a removable lid which was not 100% leak proof—so we used silicone caulking to seal the lid on tight and allowed it to dry for a full day before proceeding.

Lay the barrel down and see if it likes to sit on a certain side over the other, mark where your Twelve O Clock position (top) is.

Mark an opening to access your fish (big enough to scoop mature fish in or out too)

Drill a hole large enough for your jigsaw blade in the corner of where you want the opening, then cut opening with jigsaw (careful!). NOTE our photos, we did not completely cut out the opening, rather, created a “door” by leaving a “hinge” attached.

diy aquaponics hole cut

Step 3

Layout and plumb the bio-filter/grow beds.

We laid out this set up a couple of times before coming to rest on a configuration, working to conserve floor space while making sure we can easily access the fish tank and the plant beds—do this before cutting pipe, gluing and filling with media.

setting up aquaponics growth modules

Once you’re happy with the layout, measure out pipe cuts, determine what fittings you will need, etc to join it all together—don’t glue anything at all until you are 100% finished loose fitting all plumbing together. This includes both your drain and fill plumbing to and from the grow beds. You’ll want at least an 1-1/2” diameter drain; smaller may clog. Plastic mesh scrub pads work well at keeping media out of the drain pipe without restricting drainage.

It’s a good idea to have a filter on the pump intake to prevent clogging or fish from getting stuck on the inlet.

aquaponics system pump filter

TIP: note the second pipe, at a higher elevation, plumbed from our grow modules to the fish tank. This is an “Oh Crap” Pipe, ie emergency overflow if the main drain gets plugged up, the beds will not overflow out onto the ground draining the fish tank dry.

aquaponics overflow pipe

Step 4

Leak Test.

After assembling and gluing wait more than the recommended amount of time stated on the adhesive can. Note that usually the low VOC adhesive types are usually fast drying. Once dry,  partially fill the tank with dechlorinated water (don’t add your media yet). Run the system for at least 15 min, inspecting for leaks, overflows, blockages or other potential problems.

diy hobby aquaponics system side

Step 5

Go time!

Add the submersible aquarium heater and solid limestone chunk to the bottom of your tank.

Rinse growing media with fresh dechlorinated water to remove sediment (do this, or your system will look “muddy”) before filling your bio-filter/grow-beds, and work with it gently when filling beds or trays to prevent creating due that will turn to sludge.

diy hobby aquaponics tank heater pump limestone quaponics system return to tank

Fill the system with dechlorinated water then run the system for several hours, you should see the water turn from murky to fairly clear (that’s media bed sludge settling after handling)

Note the temperature of the tank water on your floating aquarium thermometer—is is suitable for your fish type?

If all is looking good, add your fish and plants—congrats!

 

Additional Notes For DIY Hobby Aquaponics System Building & Operation

-it usually takes 3-4 weeks for the micro-biology that converts nitrates and ammonia to forms plants can take up, so feed fish sparingly, excessive food debris will toxify the system quickly when there is insufficient healthy micro-biology to help.

-keep the system topped up to your “full” line with fresh dechlorinated water, don’t add too much colder water at once or it will shock the system.

-keep the tank opening covered where children run the risk of falling in or where animals may like to snatch up your fish.

-make sure pump and aquarium heater are plugged into a GFI protected circuit.

-dig up a few earth worms and add them to the media beds; they will break down organic residues as they collect over time.

From here, the world of aquaponics is your oyster! Have fun, experiment with different plant types, gadgets and methods—there is no single way of doing this correctly; make it yours. Prepare to be amazed at how low maintenance and productive your DIY hobby aquaponics system can be following these basics outlined here.

basil aquaponics diy system

About Erik Biksa 232 Articles
Erik Biksa has been writing about and discussing hydroponics growing, related technologies and cropping methods since 1999 in a variety of professional publications and platforms globally Erik has travelled the world learning and teaching modern growing techniques and technologies and is appreciated by many growers for his informative yet hands on approaches. Presently, he is the Editor at Grozine Hydroponics Mag.

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