Introduction: Automatic Aquarium Feeder

Picture of Automatic Aquarium Feeder

Its An Automatic Fish Feeder / Powerhead or Airpump controller

Everyday I had to turn off my aquarium's powerhead/air pump and feed manually and turn on the air again after an hour. So I found very cheap alternative to make these process fully automatic.

Step 1: What You Need?

Picture of What You Need?

Alarm Clock
555 timer IC
620K Resister
10uF Capacitor
DC Motor
AC/DC 12v Adoptor
Receptacle for food
Relay Switch
Soldering Iron

Step 2: How Its Works?

Picture of How Its Works?

I just hang the food receptacle In the aquvarium's hood, it has small holes in the bottom which small enough to hold or struck foods inside as long as stay still without shake. and attach a dc motor in it for make vibrate some seconds to drop foods, which controller by a 555 timer ic circuit triggered on by the hacked cheap alarm clock. so alarm'll automatically trigger 555 twice a day and 555 runs motor some seconds like 10 seconds in this circuit below. Normally these kinda clocks automatically snooze alarms approximately an hour. ie it took an hour to release the connection. so we can power relay switch through this and turn off the airpumps for an hour until foods clear off

Step 3: Hack Alarm Clock

Picture of Hack Alarm Clock

In most of these kinda clocks we can find two leads which connects when the alarm times up. if you can't find one, just open it and find where to solder and get leads. make sure remember the gear wheels which where it goes. so that you can assemble it back together.

Step 4: 555 Timer

Picture of 555 Timer

Solder the 555 timer with resister and a capacitor according to the the circuit

Step 5: Step 5

Picture of Step 5

Connect Motor and attach with receptacle
facilitate to attach it in the hood

Step 6: Step 6

Picture of Step 6

Connect DC 12v Adoptor the the 555 and the relay switch parallely alog with alarm clock.
connect the AC jack through the relay for powerup the pumps triggered by the electronic relay switch.which gonna disconect when times up and turns off ater an hour or less

Step 7: Finish Up

Picture of Finish Up

Assemble and pack the components safely and attach the receptacle in the hood. make sure not diped in to water or water sprinkle in it then it makes the food like mud and never fall off.
thats all folks.. just make sure its workin well and forget about feeding and controling airpumps..ENJOY


KalingoG (author)2015-09-24

Hi Paul,

I need your help to build the circuit you suggested in your post. Actually I couldn't get the idea of feeding +12Vdc into the alarm clock circuit. Also Pin 2 of 555 timer will remain high for an hour which causes hour long high output , instead of which we must required just a pulse as input from clock circuit. Can you please elaborate how you connect alarm ckt & 555 timer? Really appreciate your help.

kleinkolin (author)2015-09-24

Hi Paul, I was trying to make the aquarium feeder as per your given instruction. But I couldn't get the idea of feeding +12VDc in to the clock circuit as shown in your post. I have assembled the remaining things like Relay & 555 timer. but I'm not sure how to trigger Pin 2 of 555 timer for a fraction of second if we use this as monostable timer. I mean clock o/p will remain high for an hour but we need just a pulse to get the o/p for approx 5 sec for rotating the motor. Can you please elaborate how clock circuit is going to connect 555 IC? Really appreciate your help.. Please..

pitoyo (author)2012-03-04

how to determine the frequency of feeding? if within one day of feeding frequency was three times?

TaNviR77 (author)2011-11-10

Found the timer for my bomb... Time Bomb... ^_^

frikkie (author)2009-08-31

Here a timer circuit you can also use.I also want to build an automatic feeder since Im not always with me fishes.

antonoso (author)frikkie2010-01-09

 Hi could you upload to a website like or to download or the link

-henry- (author)frikkie2009-12-12

What is the chip that you have in the schematic?
I want to build a fish feeder and this circuit sounds like it would work perfectly.

frikkie (author)-henry-2009-12-13

In the circuit I put there?  Its  a Cmos Ic  4060 .  Theres quite a few ideas I want to use this circuit for.

-henry- (author)frikkie2009-12-14

Thanks, that's exactly what I needed.

magnum_357 (author)2009-10-02

what is really the purpose of the relay switch????

bwpatton1 (author)2009-08-22

Hmmm.....I might have to do this, being that my $$14 walmart version crapped out on me.... :( so now I have to feed my fishies everyday

PizzaPlanet (author)2008-09-02

very good instructable the diagram was very legible thumbs up!

paulrobinson (author)PizzaPlanet2009-04-22


Kinnishian (author)2008-09-04

Wow, very cool. I especially like the expansion of turning off the pump. Our small tank however has little problem with the food.

paulrobinson (author)Kinnishian2009-04-22

Thank You

1up (author)2008-09-02

Video!!! (This is a great instructable, btw. Very innovative. :) )

Gamernotnerd (author)2009-04-10

I dare you to bring this to and airport, especially if you strap it to your chest.

lol, then that'd be so miserable..

x_xPacox_x (author)2008-12-02

lol this reminding me of the breakfast machine lol 5/5

paulrobinson (author)x_xPacox_x2009-04-21


freaky123 (author)2009-02-15

If we will use a stepper instead of alarm clock....sir, what kind of stepper are we going to buy??...pls anwer mu question pls...tnx

paulrobinson (author)freaky1232009-04-21

have to do coding with any programmable IC

SteveMcCraft (author)2008-12-07

Hi, that looks pretty interesting. But I am not sure, whether I understood the mechanical part correctly. Could you share a video with us, that shows how it works. How do you prevent that the whole feeding stuff does not stuck in the hole? Or that too much is coming out? thanks and greetings Steve

watch VideoHere

wiets99 (author)2008-10-27

Good idea, but perhaps you are supposed to see another system that I think is better designed, either mechanics or electronics. Ask Mr. Google:

paulrobinson (author)wiets992009-04-21

there is nothing in or wrong page location, please correct it.

i make shooting things (author)2008-09-07

nice. Video???

m_yazhini (author)2008-09-06

your idea is very nice and easy way of feeding food but i am having

CoolKoon (author)2008-09-05

I've just realized that amateur timed bombs are probably made using the same principle (get the timing pulse from the alarm clock's beeper leads) LOL

paulrobinson (author)CoolKoon2008-09-05


stranoster (author)2008-09-02

Wow! This is a really good idea... But I just realised my fish survive on a plant now and I don't need to feed them... Oh well, other than that, this is a really well documented instructable and it makes good use of one of the many random clocks everyone seems to accumulate. Ooh another thing, the circuit diagrams aren't drawn illegibly on a piece of scrap paper, so all in all this rocks. A+

Scucci (author)stranoster2008-09-05

Yes, please. No fish lives off of a plant in a closed system like that. Please, get some betta bites or some blood worms or something. I'm amazed those enclosed betta things lasted for so long... if that was a kitten in a box or a puppy in a jar Peta would be all over it... but since their self righteous f-tards, the really only care about if it it makes noise or has fur... ANYWHO, completely off topic. Please, keep feeding the fish.

nuts4fiber (author)stranoster2008-09-05

No fish can survive on a plant! If you were sold one of those Betta (Siamese Fighting Fish) in one of those vases with a plant whose roots dip into the water, and they told you that it was a self-contained eco-system, they were wrong! I'm hoping you read this and run out to a pet store and get some Betta Balls right now! Follow the instructions on the label for the amount to feed your fish. You'll also need to buy some water conditioner made for fish. It will take the Chlorine and Chloramines out of the water that you should be replacing the old water in your bowl or vase with on a weekly or bi-weekly basis. Google for information on how to care for Bettas. They are wonderful fish and very responsive to their owners if kept in good health.

zale (author)2008-09-04

What kind of tank have you got that you need to turn off the air pump to feed the fish?

Scucci (author)zale2008-09-05

For the powerheads to be an issue, there would have to be pretty powerfull... I'm better FW planted or SW tank, maybe reef. When I kept fish in with my corals, I had to turn the pumps off to feed the fish because of the food getting blown into rocks and getting sucked over the overflows.

votecoffee (author)zale2008-09-04

the bubble filter systems in some tanks cause the food to sink instead of staying on top till the fish eat it. causes more waste food on bottom of tank. I've had that problem in the past so I'm guessing that's why he does it.

xxzalexx (author)votecoffee2008-09-04

I see... makes sense. I only have goldfish - I'm goldfish obsessed to be honest, I never really think of other kinds of fish. They're happy eating off the bottom (in fact some experts say it's better for them not to eat off the top of the water). thx

votecoffee (author)xxzalexx2008-09-05

: ) Had goldfish. they're good for eating everything... including other smaller fish :P I still had swordtails after my goldfish got so fat he popped (long story, the swordtails rebelled mand he was very, very fat), and they tend to let food that sinks just stay on the bottom. They're not quite as gluttonous as the goldfish was, had their 5 second rule and all : )

Mojo_JoJo (author)2008-09-04

I tried to make something similar but I used a different mechanism to rotate the container with the fish food. I used an old small clock that I had and removed it from the housing and removed the clock face and hands, then made a hole at the back of the container and attached it to the hour hand spindle of the clock. The problem with this was that the fish get fed every 12 hours, the other problem was that the fish food got soggy due to the moisture in the tank and clogged the openning of the container.

musicalbee2003 (author)2008-09-04

That looks rather Steam Punk!

Wyle_E (author)2008-09-02

I don't see the reason for the diode in series with the motor. I'm used to seeing reverse-biased diodes across the terminals of motors and relay coils, to protect the rest of the circuit from spikes generated when the coil is de-energized.

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