# Nano Tank Heater Module (56K)



## AquaDean (Nov 20, 2009)

I’ve posted this on another forum so if this is a repeat for you I apologize. But I wanted to post it here because I want to use some of this as an example for some other DIY projects and wasn’t sure about posting links to other forums.
I find planted Nano tanks very intriguing yet when viewing the various photo’s of tanks that are posted I’m always disturbed by all the equipment stuck inside the tank. Especially the great big honking heater!!

I’ve played around with a couple of these tanks, the first being the 3 gallon Picotope and currently the 4 gallon Finnex and my new 1 foot Cube tank. I see where they make smaller light fixtures, HOB filters and even small canister filters (I’m using the ZooMed 501). But why can’t they make a small 2” or 3” heater that would be easy to conceal in the tank. I know the technology is out there but I’d guess that the demand is not great enough. So those of us with Nano tanks that need heaters have to put a great big honking heater it the tank and try somehow to hide part or most of it. I’ve purchased at least four different 25-50 watt heaters in the quest to find that perfect one for a Nano tank. So let’s start there and then I’ll show you how I hope to get it out of the tank.

The best heater that I’ve found for a Nano tank is the 50W Catalina Aquariums Titanium heater. This heater is the smallest one that I’ve found that also gives you complete control of the temperature. There are some small heaters out there that are preset and you don’t have any control over the tank temp, but I wanted that control. This heater is only about 5 ½” long and a little over ½” in diameter. The temperature dial is integrated into the plug so there is no knob to twist in the tank. I’ve found that once set this heater is very accurate but the temperature is not exactly what you read on the dial, it’s usually within a degree or two. So this is the heater that will be the subject of my DIY.










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DIY Building a Nano Tank Heater Module*

Let’s start with the materials that I’m using for this project. Most center around 2” PVC fitting that you should be able to purchase and any large hardware store such as Lowes or Home Depot. I’ll provide a link for the parts that I couldn’t get from my local stores. 

Materials list one each required unless noted:
 2” PVC coupling (slip/slip)
2” PVC plug (slip)
2” PVC Male Adaptor (slip/threaded)
2” PVC Cap (threaded)
2” PVC pipe (only needed a 3” long piece)
3/8” x ¼” Nylon hose barb elbow, the barbed end fits ½” OD tubing and the threaded end is ¼” male pipe thread. You will need two of these.
Heyco M4516 Liquid Tight Cordgrip, www.heyco.com, I ordered mine from a local distributor, cost 45 cents each.
4 small zip ties
Medium bodied PVC cement
Aquarium safe Silicone Sealer
Teflon tape












First I glued the PVC plug into one end of the PVC coupling. I use lots of the PVC cement on both surfaces and slide the joint together a far as it can go. I use paper towels to immediately wipe off all excess glue both inside and outside. 

Next I drilled with a 7/16” bit I drill three holes; two located in the PVC cap and one in the side of the PVC coupling/plug. You’ll have to use the pictures as a guide as I didn’t measure these except to be sure that there was clearance on the cap for both threaded fittings. These holes were then tapped with a ¼” pipe tap which I found at the hardware store for about $5.00. I just got the tap lined up straight and turned it with an adjustable crescent wrench. Taps are designed to be used with an oil lubricant so I just used some vegetable oil because I knew I could clean it easily with soap and water. 

Once the holes were tapped and all the oil was washed off I installed the three threaded fittings. I applied a small amount of the Aquarium Silicone to the threads and then threaded the fitting into the holes as far as they’d go. Be sure not to cross thread or go too far and strip the threads. I figured when cured the silicone would form a water proof thread lock. For the cap be sure to install the barbed elbow before the cord grip, if you do it the other way you’ll quickly find out why. 












Next I glued the 3” section of PVC pipe into the other side of the coupling, again being sure to wipe off all the excess glue. The glued the male adaptor onto that whole assembly. Check out the next two pictures to see where I’m at. 























Now I move on to the fun part; the cord grip fitting has a ¼” hole through it and I need to get either the heater through it or the plug though it. I’ve seen other heater module DIY’s where they buy a cord grip that is large enough for the heater tube but when I started thinking about this project I was thinking on keeping the size smaller. So I only had two ways to get that cord though the cord grip. One would be to cut the cord and thread it through and then splice the wires in the right order back together. I looked at this method; there were four wires in the cord, a black, a white and two red one. I’d have to keep track of the red ones to be sure to get them back together the same as they were before the cut. Not hard, could be done, but would look like a cord that was cut and spliced. 

Option 2 (the one I took), disassemble and reassemble. The plastic enclosure around the plug is translucent and I could see that it was not glued together and that there were four solder joints to the printed circuit board. I’ve got a little electronics skills and a decent soldering iron so it came down to being able to open the plastic plug enclosure. I donned the 3X reading glasses and went at figuring out how to pop open the two halves of the enclosure. With some careful squeezing and prying I was able to get the case apart without any damage at all. 












Just to put this all in perspective just a little bit, before I jumped into this project and purchased all the fittings I first figured out that I could get the enclosure open. So really this would be the first step.












Once open I quickly marked the wires and circuit board for their locations. A digital camera and inkjet printer are a big help when doing this. Then de-soldered the four wires and removed the wire guard which proved to not be all that easy. 












I found that using a very small screwdriver and an ice pick helped to loosen it up so I could slide it off the cable. Once off a big sigh of relief, just had to push the wire through the cord grip (in the right direction of course) and reassemble in the reverse order. If you do this you must be very careful with the re-soldering as it just takes a tiny bit of solder. Plus be sure that you have the wires in the correct location. 





















Now to keep the heater relatively in the center of the module, this was easy at the top because the cord coming through the cap would keep it there. For the bottom, zip ties! Take a look at the pictures below, I put four of them together and then just tightened the one around the bottom of the heater and trimmed to the length so that the heater would stay near the center of the module. 





















At this point I just need to let the PVC glue and silicone cure before the water test. If that goes well then it will be hooked up to a tank. Stay tuned. . . More to come


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## AquaDean (Nov 20, 2009)

The next step is the water test. First to make sure there are no leaks and second to test the heating ability of the module. No better place to test than on the living room carpet behind the couch. Of course if you are not sure of yourself I’d recommend testing in the bath tub or on a floor that doesn’t matter if it gets wet. I was pretty sure of the seal and all so I wanted to test where I could get some decent pictures. 

So first I wrapped the big threads on the male adaptor with Teflon thread seal tape. Commonly in the plumbing section of your hardware store and simply referred to as Teflon tape. About 4 or 5 wraps covering all the threads is all it takes. Wrap nice and smooth and I like to go in clockwise direction, the same direction as when I screw on the cap. Caution, do not overwrap and have too much build up of the tape, just 4 or 5 wraps around will do fine.

Next I simply screwed on the cap assembly with the heater installed in it. I only tightened this as tight as I could by hand. No need to over tighten with humongous pliers or wrenches, just really good hand tight will do. 

For the test I used a 5 gallon bucket of water, a small water pump, and tubing the same size as will be used in the final install. I hooked it all up as in the pictures below and plugged in the water pump. In about 30 seconds the module had filled and water was flowing. No leaks, YAY!! 

I waited 20 minutes or so, still no leaks so plugged in the heater, no sparks, no shock when I put my hand in the water, and the pilot light came on. All good so now to test if it heats and holds the temperature steady. The temperature of the water started out at 65 degrees Fahrenheit and now after about three hours is at 70 degrees. I set the dial on 74 so will see if it gets there and then of course holds the temp constant. I ran this test for several days both raising and lowering the temperature and found that I have a working DIY heater module. Here are the testing pictures:










































If everything goes well for the next couple days the next step will be to hook it up to the ZooMed 501 and the tank.

Everything did go well and the heater module has been hooked up to my 4 gallon Finnex tank for about a month now. I've made a second module for my new cube tank and it is working great also. I haven't had time to get pictures yet but will in the next several days.


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## CL (Mar 13, 2008)

What a cute little inline heater :tongue:
Pretty cool stuff. Well done.


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## insta (Jan 27, 2010)

Very nicely done.


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## tuonor (Nov 26, 2009)

Nicely done and great DIY instructions! 

I have a couple of these heaters and definitely recommend them although mine need to be calibrated (both are several degress optimistic).


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## TeamTeal (Mar 31, 2010)

very nice!
good instructions too


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## AquaDean (Nov 20, 2009)

Thanks guys, I've made another one of these just a little bit taller and added in a glass CO2 diffuser. It seems to be working great so far. I'll have pictures in about a week, I've had to go out of town for a few days.


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## crf529 (Jul 24, 2010)

G'day mate. Fantastic idea and execution here, very cool!

I'm currently setting up a nano cube for a shrimp only tank at the moment and already have an Eden 501 filter which i think is what the call the ZooMed's over here in Aus. Just wondering how it goes all hooked in terms of flow and if you've lost any/much?

Seano


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## CL (Mar 13, 2008)

Hey, Dean. How's the inline ceramic diffuser holding up for you?


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## mistergreen (Dec 9, 2006)

Has anybody thought of combining an inline heater and a CO2 reactor into one?


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## ttatummm (Aug 29, 2007)

Great Instructions, thanks so much.

I find it amazing that years later there are still no commercial inline heaters for small tanks. It doesn't make sense to me, nano tanks are really popular and the smaller the tanks the more the equipment sticks out like a sore thumb. Again and again I see folks on aquarium forums expressing the desire for small inline heaters, yet there are still none on the market.

It was nearly ten years ago the I went looking for a small in-line heater and couldn't fine one, now I am setting up another nano tank (9.4 gal) and I am in the same boat. But with your really nice instructions, I think I can DIY it.


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## Botia dude (Feb 6, 2005)

mistergreen said:


> Has anybody thought of combining an inline heater and a CO2 reactor into one?



I did it on my UNS 90U and for a previous 17g tank. This build used clear 3" PVC. I'd probably switch the heaters orientation next time I do it for better flow. 










Bump: Nice tutorial for this project. It's always nice to get equipment out of the tank.


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## PlantedRich (Jul 21, 2010)

I've wondered several times about using the small flexible heat pads for nano heating. Seems they would provide the small amount of heat and could easily be controlled with one of the cheap digital temp controllers. I build a system using light bulbs as heat for an orb but the orb itself was such a disaster that I never really used it long enough to decide about the heating system. Since heat rises, putting the heat under a tank seems like a good way to avoid having it IN the tank.


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