Aquaponic Gardening

A Community and Forum For Aquaponic Gardeners

DIY submersible water heater, build your own water heater

***Be sure to use a GFI plug with this!***

here is a link to the Through-Wall version

 COPPER WARNING! most of the elements are made from nickel plated copper and should not be used!

I have not found stainless elements at Home Depot. Some of the Lowes stores have them.

A quick search on the web will find several types in the 240volt range.

Some links to try:

 1500 watt in the 120 volts stainless steel unit.


 here are some stainless steel options. they only make them in 4000 watt+ at 240 volts.


I've made a few changes to the heater parts list and instructions..


1500-5500 watt stainless element

12 awg cord

1-1/2" rubber coupling

1-1/2" reduced to 1" threaded

1-1/2" reduced to 1/2" threaded

1/2" water tight connector


Temp controller
















install the element into the 1-1/2" - 1" reducer.

...these are made to be inserted in one direction, so you will need to use a grinding wheel, or improvise, to remove the "stop" portion of the fitting.

some are sold with a round edge (pictured here) and some are squared (pictured above)

after removing the stop, connect the wires and install into the rubber coupler.





Here are a couple different

submersible options.

the top one has the wire ran inside the 1/2" irrigation "funny pipe" and fittings.

both work great!










I have used a heavy duty timer to control the temp. 15 mins on the hour will keep 300 gallons warm.

pex supply has thermostats

Use a GFI plug with this unit!





Views: 26922

Reply to This

Replies to This Discussion

I will do a 4000 watt with a 240v thermostat and post it asap.

Thanks Rob, 

 I got the part at Lowes (miuns the thermo first). I'm making heaters this weekend. 

Thank you for sharing this with the group.


Rob Nash said:

The thermo will have a place to hard wire the heater.
Austin gets pretty cold,but rarely snows. The fifteen mins is only when it's in the 40's and it will keep it in the 70's. When it starts to get into the 30's you will have to wrap it and cover it to keep it warm. This is the time of year when I start to regret having tilapia.
Rob, it appears that you are using a hot water heater element. You could simply use the same brand hot water heater thermostat as well. Home Depot sells a water heater kit with element and thermo for $20. The thermo simply contacts a tank surface that would conduct heat, not necessarily measuring the water itself. I'm not sure how warm the lowest setting is. It may be too hot for fish, dunno.

     If you install this heater in metal pipe could you not then add a simple water heater themostat on the outside to control the tempature ? The controller may need to be placed  a distance from the heater [on metal pipe ] so it can read the temp. you are after.

Just a side note: 2kwatts/ 120v is gonna pull over 16amps ,so you may want to upsize to a 20 amp breaker to avoid errant tripping.

Just realized you where using 14 gauge wire( I gotta get more sleep,lol) that's only good to 15Amps used #12 instead .found a 1500W at lowes you can use with a 14 gauge and you don't need a 20Amp circuit.I'll let you know how that works out.Hows that heater we hooked up working out BTW

the heater is doing great. thanks for the help with the electrical upgrades.

what is the correct size wire for a 4000 watt on 240V?

Awesome...sure anytime,Let me know if you need any help wiring up your new place .Same ratio ,So 12 gauge fused at 20Amps is fine.You can always go higher ,If you got some 10 gauge laying around use that.Might be a little tougher to work with though.

Great design!! I built one & installed it in my 200 gallon tank. The water was 50 when I plugged it in, the outside temp got down to 30 and the water temp was 70 the next little katchfishes think they got moved to Miami!!!

$47.00 in parts at the local mean hardware store. 

I gots tomatos turning red on the vines & here it is nearly december!! The fresh ones in the thanksgiving salad were wonderful.

Hey Rob here's my 1500w heater install update,Had a few leaks so I Installed a 2 inch Uniseal.Plastic in IBC was kinda weak, so surrounded it with plexiglass.

alex batista said:

Hey Rob here's my 1500w heater install update,Had a few leaks so I Installed a 2 inch Uniseal.Plastic in IBC was kinda weak, so surrounded it with plexiglass.

Reply to Discussion


© 2024   Created by Sylvia Bernstein.   Powered by

Badges  |  Report an Issue  |  Terms of Service