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Emily small aquaponic system

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Revision as of 14:53, 7 May 2015 by Shamrockew (Talk | Contributions) (Construction)

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Engr305 Appropriate Technology page in progress
This page is a project in progress by students in Engr305 Appropriate Technology. Please do not make edits unless you are a member of the team working on this page, but feel free to make comments on the discussion page. Check back for the finished version on May 15, 2015.



The first time I, Emily Wood encountered an aquaponics system, it was on It got me really interested in the idea of growing my own food indoors in a sustainable way. However, at the time I was a student living in the dorms at Humboldt State University and didn’t think I had the space, money or time to create my own system. Additionally, I would have to deal with somehow eventually dismantling it and moving the system when I left the dorms. The goal is to build a functioning small scale aquaponics system that takes up minimal space inside my bedroom. I currently reside in a small house in Arcata, California with three other roommates. The food and/or herbs grown will eventually be used by me and my roommates. In addition to producing some of my own food with the system, I also hope to inspire my roommates to become more self sustaining as well. If I can create a small aquaponics system then I think most people can too. The project began on January 31st 2015 and will continue through mid-May 2015.

Problem Statement

The objective of this project is to demonstrate that you can build your own self sustaining aquaponics system relatively inexpensively, create a system that can be used in a small apartment or dorm room, can be easily transported to a new location and of course, generate edible food.

Project Evaluation Criteria

The following Criteria will be used to assess the success of this project. These criteria were chosen based on the personal needs of the owner. The scale (1-10) represents the importance level of meeting the constraint of each listed criteria.

Criteria Constraints Weight
Educational aspect Must demonstrate a working concept of how an aquaponics system functions
Maintainability Must be easy to maintain with little time and energy
Aesthetics Must be pleasing to the eye
Cost Must be between $0-$75
Vegetation Must be edible
Functionality Must successfully generate food
Transportability Must be easy to move to a new location
Size Must fit through a door frame

Literature Review

This is a review of the available literature pertinent to my small aquaponics system.

Aquaponics basics

Aquaponics is a known for being a sustainable method of producing edible vegetation and fish. It is similar to {hydroponics} in that both methods grow plants in cycled water instead of soil [ book]. However, unlike hydroponics, the system is wholly dependent upon itself for the natural cycling of nutrients throughout the system. No additional outside input of nutrients is needed in order to balance and maintain the system since the system utilizes a biological nitrifying filter [ ]. Additionally, there is no need to change out and waste the water if salt and nutrient levels get too toxic. The aquaponics system naturally filters and maintains itself. This is achieved via nitrifying bacteria that gradually build up and live in the grow media [ ]. There are two different types of bacteria, the Nitrosomonas and the Nitrobacter and they are essential in turning the ammonia laden fish waste into the nitrates the plants utilize. The Nitrosomonas are the ammonia-oxidizing bacteria and are the first step of the nitrifying process. They work to turn ammonia to nitrites. The second step, involves the Nitrobacter or “nitrite-oxidizing bacteria,” which work to break down nitrite into the nitrate that is used by the plants [ ]. The bacteria break down the ammonia from the fish waste, and convert it into nitrates which the plants can then utilize. At the same time, the plants are working to filter out the nitrates from the water before it returns back to the tank [ book]. This symbiotic process not only cleans the fish water, reducing the ammonia levels to levels that are safe for the fish, but also provides the necessary nutrients for the plants to grow. Aquaponics is an attractive option because once set up, the system can run efficiently on its own without additional human input (unless you are feeding your fish manually instead of a timed fish feeder) [ ]. It has been shown to produce food just as efficiently as hydroponics systems [ ]. Additionally, in the long run, aquaponics systems can be a cheaper alternative to hydroponics because there is no additional costs associated with buying the necessary nutrients that must be added in order to maintain a hydroponics system. Aquaponics also has a water usage advantage over hydroponics because the water never needs to be dumped out and discarded. The only net addition of water in an aquaponics system is when the water level in the tank gets low due to evaporation [ ]. [1]

Composting concerns

Short paragraph on the concerns.[2]

Types of Systems

Short introduction to types of aquaponics systems. [3]

Types of Grow Media

An appropriate type of grow media should be chosen for the size and needs of a system. The size of the filter substrate or grow bed for maximum ammonia removal is, for every 1 gallon per minute of recirculating water a square foot of filter surface is needed [book ]. Many aquaponics systems use the same types of grow media as hydroponics. Popular choices of grow media include; gravel, river stone, crushed stone, expanded shale, expanded clay pebbles (hydrotons) and synthetic [ web]. The diameter of the grow media should be around 12-18mm. This size provides an adequate water retention to aeration ratio to prevent the roots from rotting or the growth of mould [web ]. This size range is big enough to allow the root systems of plants to latch onto and grow. It also allows solid waste to pass through without getting clogged. Another aspect to keep in mind is to chose a grow media that is pH neutral so it won’t change the pH of your fish tank.

Types of Fish Used

The type of fish used in a system depends on several factors such as, how large your fish tank is, what climate you live in, what temperature water the fish survive in and whether or not you plan to harvest the fish as a food source. There are many different species of fish that can be used in an aquaponics system. Tilapia, blue gill, sunfish, crappie, koi, fancy goldfish, pacu, trout, carp, catfish and largemouth bass are just a few species that have proved to do well in an aquaponics set up [ ]. Some fish like tilapia, do best in warm water so special considerations such as an addition of a heater must be kept in mind. [3]

Types of Plants Grown

There are many different types of plants that can be grown in an aquaponics system. The limiting factors on what grows best are how many plants you plan to grow and whether or not you have enough fish to support the nutrient needs of the plants. Too little plants and you system won’t get filtered properly. Too many and your system cannot support healthy plant growth. One of the most common types of plants grown are leafy-green vegetables. Lettuce and spinach can easily be harvested because their leaves grow above the surface of the substrate. Other vegetables such as tomatoes, peppers, squash and snow peas grow well. Herbs are another popular choice and have been shown to do well. The only types of plants that do not thrive in an aquaponics system are root and tuber crops.


Drilling holes into PVC to create water irrigation points

Construction of the project was relatively simple and only took two days to fully assemble and complete. Additional construction time was needed later on when a bell siphon was added.

How to Build

The following instructions explain step by step how to build the small aquaponics system.

How to Build the Small Aquaponics System
Step Measure and cut PVC into three 20" sections, four 3" sections and 1 5" section using a hand saw.
Image: barbednipple.JPG
Step In one of the 3" sections, drill a hole for the threaded nipple and insert it.
Image: measureandmark.JPG
[[ How the PCV should look after assembly. |180px|3]] Step Assemble the 4 90o elbow and 2 tees to the cut PVC pieces.
Image: drillingholesinpvc.JPG
180px| Near one of the four corners of the plastic tub, cut a 1" hole using. This is Where the drainage outflow will be located. Step Image: bushing.JPG : You want to create a water tight seal.
180px| Insert a rubber washer onto the bushing. Insert the bushing into the 1" hole you created. Attach another rubber washer to the end. Screw the threaded connector onto the bushing to create a water tight seal. Step 7: Attach an 90o elbow to the end of your 5" PVC piece and insert the piece into the threaded connector located at the bottom of the plastic tub.
Zip tie going through one of the holes and looping around the PVC drip piping on the inside of the tub. Step 8: Drill four holes (two on each side of the plastic tub near the top) where you will thread zip ties and anchor the drip piping. Put the zip ties in and secure the drip piping.
These are the materials needed for the bell siphon. Step 9: Build plastic bottle bell sipon
Side view of the plastic aquarium tubing attached to pump and nipple barb. Step 10: Attach plastic aquarium tubing to nipple barb and to the pump. Place pump into fish tank and plug pump into the 15 minute incremental timer.
This cycling process will allow the beneficial bacteria to build up. Step 11: Add your grow media substrate. Let fish tank cycle for about 4 weeks.
Finished aquaponics system with plants starting to grow. Step 12: Finally, plant your plants!


In order to meet the goals and objectives of this project the following tentative timeline has been established. This will serve as a guide for the projects' development.

1/31 Purchased PVC pipe, plastic tub, grow media
1/31 Initial construction and assemblage
2/1 Completed construction and assemblage
2/1 First test run of system before adding grow media
2/1 Washed grow media
2/7 Purchased 6 additional goldfish
2/14 Purchased plants
2/14 Separated soil from roots
2/14 Planted spinach, butterhead lettuce and Tuscan baby leaf kale
2/14 Established baseline height of plants
2/14 Began testing water pH levels
2/21 Began weekly measurements of plant height (compare to control group)
2/25 Calculated energy usage of the system (kWh used by water pump)
2/27 Obtained ammonia/nitrate/nitrite test kit
2/27 Started bi-weekly water testing for pH, dissolved oxygen, ammonia, nitrate and nitrogen levels
4/3 Created and installed bell siphon
4/4 Bought Pink Hungarian lettuce and strawberry plant
4/4 Planted Pink Hungarian lettuce and strawberry plant
5/7 Harvest food (sooner if possible)


All of the items for this project have already been purchased. About half of the project materials were gathered from what I already had laying around my home. These items could be easily found at an aquarium store, craigslist, thrift store or garage sale rather inexpensively. The total cost did not take into account the local and state sales tax rate of where I bought the items ( 8.75%).

Quantity Material Source Cost ($) Total ($)
3 Schedule 40 PVC Pipe (4ft) Orchard Supply Store 0.32 0.96
5 90° elbow Orchard Supply Store 0.27 1.35
2 tees Orchard Supply Store 0.35 0.70
3 1"x1/2" slip joint rubber washers Orchard Supply Store 2.27 2.27
1 31 QT plastic tub Orchard Supply Store 11.99 11.99
1 3/4"x1/2" PVC bushing Home Depot 0.40 0.40
1 5/16" plastic aquarium tubing My house 0.00 0.00
1 threaded nipple- 1/4" barbs My house 0.00 0.00
1 1/4" galvanized steel screen (4"x6" used) My house 0.00 0.00
1 15 minute increment timer Hydroponic Warehouse 14.00 14.00
1 20lb bag 3/8" expanded shale Hydroponic Warehouse 21.00 21.00
6 zip ties My house 0.00 0.00
1 Pondmaster Pump (5.5W Hmax 30" Qmax 75GPH) My house 0.00 0.00
1 10 gal fish tank My house 0.00 0.00
1 aquarium heater My house 0.00 0.00
2 15"x 2"x 3/4" wood My house 0.00 0.00
6 goldfish Petco 0.07 0.42
18 plants Arcata Farmer's Market 12.00 12.00
Total Cost $65.09



Maintenance of the grow bed, pump, plants, fish and water should be performed daily, weekly and monthly.


  • Feeding of fish (once in the morning and once at night).
  • Checking temperature of water to make sure it is between 65-68 degrees Fahrenheit (for goldfish). Other fish may require different temperature water.
  • Check the pH level of water. It should be Between 6.8 and 7.0.
  • Check plants for any bugs or insects.
  • Check ammonia levels. level should be at or below 0.5ppm.
  • Check nitrate levels. Levels above 150ppm could indicate that your system does not have enough plants.
  • Check to make sure the pump is working properly.
  • Check to make sure piping and tubing are not leaking.
  • Check to make sure siphon is in place and working properly.
  • Harvest food
  • Add additional water to tank when level gets low
  • Buy additional fish
  • Plant new plants



How to Do Something
Description Step 1 : Do something.
Description Step 2 : Do something really complicated but made simple, etc.


Testing results

Water Quality

Date Fish tank
2/28/15 7.64
3/14/15 7.28
3/28/15 6.90
4/11/15 6.83
Date Fish tank
2/28/15 15ppm
3/14/15 15ppm
3/28/15 15ppm
4/11/15 15ppm
Date Fish tank
2/28/15 65ppm
3/14/15 64.5ppm
3/28/15 67.5ppm
4/11/15 65ppm
Dissolved Oxygen
Date Fish tank
2/28/15 3.8ppm
3/14/15 3.3ppm
3/28/15 3.5ppm
4/11/15 3.9ppm

Bell Siphon Test



Discuss the testing results.

Lessons learned

Discuss lessons were learned during this project and what you would do different next time.

Next steps

Discuss any next steps for the project as it goes on into the future.


This is only how to troubleshoot basic operation. For complex issues, the solution might just say contact ________. It should be a table in this format:

Issue Solution
Pump stops working First, make sure it is plugged it. Then take it out of tank and smack it on the palm of hand while running it under clean tap water. This will help loosen and unclog any trapped debris.
Does not turn on Make sure it is plugged in
Another issue Et cetera


This was an individual project completed at the users' home during the Spring 2015 semester.

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