DIY water heater aquarium heater

[Rmelz]

I know people have posted things like this before, but I made a few changes to the designs i've seen. I have a 1/2" OD ss coil I made from 10' of tubing that sits in my sump. I bought a 120V thermostat with a submersible sensor off eBay that switches the neutral to a potable water recirculating pump on my hot water tank.. I have pex running from the tap on the hot water side of the heater that runs to the coil and back from the coil to the return pump. It heats my 75 gallon tank and 75 gallon sump very very nicely and it's very efficient to run.
Thought I would share.

Thanks

 

[EighthNotch]

Nicely done. I've seen similar design ideas as well. Whats your thoughts on using a setup like this on an electric water heater? I was curious if I would still see energy savings.

 

[fishguy306]

You would spend more money using this system on an electric water heater instead of using heaters directly. This only works with gas as it is so cheap. Heaters in the tank are as efficient as electric heaters will get for a tank.