How to make an Automatic Fish Feeder with Simple Materials?

An automatic fish feeder can really take away the monotonous task of feeding the fishes on time every day. Where it really helps is when you donâ€™t have the time in your busy schedule to tend to the fish.

This is a great way to keep the fish fed when you are away for a holiday or even work. It also helps to prevent overfeeding and fouling of the fish tank since it can be programmed to feed just the right amount of food for the fish stock in your fish tank.

An automatic fish feeder can be used in both aquariums and Aquaponic systems alike since it is scalable and settings can be adjusted to suit the ration and fishes in your fish tank.

An automatic fish feeder can be made by using these simple materials

Large container – To hold the food
Wood – For the Support structure
Wire – For the DIY screw to feed the food
PVC pipe – To Channel the food
5 RPM Motor – To turn the screw
Timer Switch – To power the motor at a scheduled time

See our post on automating an aquaponic system here using the fish feeder we made.

Additionally, our article on protecting an aquaponic system from a power failure can come in handy in preparing for such events which can be disastrous to an aquaponic system.

Automatic Fish feeder I made for my Aquaponic System (video)

The video first shows the design and then how it works as the fishes feed.

Making an Automatic Fish Feeder using Simple Materials

1. Large container –

A large container is used to hold the food for the automatic fish feeder. For my build, I prefer to use a 5lb protein shake bottle because itâ€™s large and can hold a lot of food.

Although this may be a good thing with respect to holding capacity, you don’t want to have food in there for too long.

The fish food tends to spoil when left for long periods. So regular checkups should be done in this case or a smaller container can be used to just eliminate this problem altogether.

The bottom of the food container becomes the top of the fish feeder. This is done so that the food is channeled down towards the opening of the PVC guide and the screw.
At the top of the bottle you can use the opening of another bottle and cut and retrofit it so that it creates a new port to refill the food when it’s empty.
The lid of the original bottle is kept on and a hole the size of the PVC guide is cut so that the guide can fit through it.

2. Making the wooden Structure –

Wood is readily available and can be cut and joined with simple tools. Metal on the other hand can also be used to give a longer life span of the structure if you wish.

Two pieces of wood are needed to construct this fish feeder. The wood creates a 90 degree where fish feeder sits on the bottom piece and the vertical piece is used for support.

Two ports at the bottom of the screw are cut to allow fish food to fall into the fish tank.

On the vertical piece, a hole the exact size of the 5 RPM motor is cut so that the motor fits snugly into it.

In this build, I used a 6 X 9 inches piece of wood for the bottom and a 3 X 16 inches for the vertical support, and both pieces of wood were screwed together.

Cutting the PVC pipe to guide the food –

A Â¾ inch PVC pipe should be used to guide the food from the bottle by the screw then into the fish tank.

Cut a Â¾ inch piece of PVC the length equal to diameter of the Food container
You can use a PVC cutter for this
An opening should be cut on the PVC guide to allow food to fall into it.

See the pipe cutter here.

Making the Food screw –

Hardwire is used to make the screw. The screw diameter should be small enough to fit into the PVC guide and move freely.

Locate and cut a piece of hard wire about 2 feet long.
Wrap the wire around a hard pipe and from it into the screw
Remove the wire and stretch it out to the required size
One end of the wire straightened to be horizontal to the direction of the screw which is then bent to fit into the hole on the motor.
This connection is what causes the motor to turn the screw.

Selecting the Motor Driver –

A slow spinning motor was used for this build (5 RPM). I found it in an old oscillating fan and decided it will go well with this automatic fish feeder.

The plus side of using a motor like this is that it doesnâ€™t require additional gears or pulleys to break down the speed at which the screw turns.

I have found the same motors on amazon which are really cheap. See them by clicking here.

The Timer Switch –

The timer switch will be used to power on the motor and turn it for a specified time period. This allows for a specific amount of food to be fed to fish on a routine basis.

The timer switch I used is the BN-LINK 7 Day Heavy Duty Digital Programmable Timer Switch with these features –

Click here to view the switch on amazon.

Versatile and customisable and you can easily set up to 8 on/off programs.
Has two grounded outlets which are controlled simultaneously
Settings can be as short as one minute.
This switch doesnâ€™t require wifi

The one-minute setting can give you enough time to feed the fish the required amount of food.

If more food is required the settings could be changed so that the timer runs for a longer period of time when it comes on.

To get shorter feeding times you can use a sonoff wifi module from amazon. You can find it by clicking here.

View on Amazon

This switch features –

Very short times, as short as one second
Controlled by wifi
Any amount of timers can be set.
You can turn it on from anywhere which means, you can Feed the fishes from anywhere in the world
It can be controlled with Alexa

Supporting the Fish feeder –

The entire unit should be supported and allowed to hang above the fish tank. This should be done so that the food will fall into the fish tank.

In an Aquaponics system where the feeders are outside, it should be covered from the elements so that rain and moisture don’t get inside. Moisture can cause the food to go bad fast.

Aquaponic systems also tend to attract unwanted visitors such as ants. Ants can easily find their way into the container and eat the food.

One way to prevent this from happening is to coat the supports, which are holding the automatic fish feeder in place, with grease.

The grease should not be toxic to the aquaponic fishes and will prevent pesky ants from invading the fish feeder.

See our article on how to control pests in aquaponics.

Automatic Fish Feeder in Aquaponics –

I have used this automatic fish which I have made for myself in my aquaponic system for the past three years and it’s still going strong.

The automatic fish feeder has to automate my aquaponic system to some point. I don’t have to go feed the fish every day which is a big help since I work a 12-hour shift.

The food is fed routinely, twice a day, every day. So I know that the fishes in my aquaponic system are well fed.

It allows me to also limit the amount of food being fed to the fishes in my aquaponic system. I can also increase the feeding time if I decide to add more fish to the system.

Notes:

Use a glue gun to fill any unnecessary space and add support for the components
Use tie straps to wrap around the food bottle and the vertical wood for extra support.
The length of the screw can be adjusted to adjust the amount of food which is being fed to the fishes at a time.
The amount of food being fed to the fishes will be determined by the amount of fishes in the system.
Too much food can cause fouling of the system and unwanted system pH swings.