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External Heater

Tomp91

Member
Joined
4 May 2020
Messages
56
Location
Leeds
Does anyone use an external inline heater?

I think its a great idea but the fact there are not many out there makes me think there is something bad about the design in general.

As far as I can see there are only 2 products available the Hydor and Chinese ebay thing of a similar design.

I really want a solution to get the heater out my tank. Using a Eheim Classic 250 for the filter.
 
The hydor ones work. Iv'e had one runnning for 10years no issues.

There are issues with them that need taking into consideration before opting for one
1. They are rather large you need adequate cabinet space to hide one in aswell as a external filter / pump.
2. If your external filter fails you are without a heater.
 
You can also DIY it... :) If you search Youtube for DIY inline heater you'll find several designs using a regular heater and turn it into an inline.

I once made something similar with a 12 volt 110-watt heater cartridge... But that's something different.
Here you see it at the LH side of the picture mounted to the wall.
dscf7602-kopie-jpg.jpg


Depending on your DIY skills there are quite some options out there.
 
I use a 200W Hydor external heater for my 25 litre nano tank.

Obviously that wattage is way too big, and would boil the tank rapidly if it ever stuck on, so I drive it using an STC-1000 temperature controller so that there are two thermostats regulating the temperature.

Originally I had the tank temperature regulated by the Hydor, with the STC-1000‘s temperature set just slightly higher. The problem with that is that the Hydor’s thermostat is sensitive to very tiny temperature variations, so on a very small body of water the thermostat was cutting in and out every couple of minutes. Eventually it failed after a couple of years of constant switching.

I now have the temperature regulated by the STC-1000, with the temperature tolerance set to 0.3°C. This results in far less switching. The Hydor’s thermostat is set a little higher, and normally remains “closed”. I do occasionally check that it still works, although it’s unlikely to stick closed given that it’s never switching (the normal failure mode is “welding” due to arcing during switching).

The fact that the first Hydor lasted a couple of years in a rather extreme usage scenario I think indicates that it should last for many years in normal use.
 
Thank you very much. I will have a look at DIY tonight and probably go with the Hydor and controller. I'll be using it with a 60L so mines pretty small too, sticking on was my main concern a few amazon reviews mention that!

Regarding the controller, could you not rely on the Hydor thermostat and just have the controller cut it off at a high upper limit, so really the controller would only kick in if it stuck on more as a fail safe with a higher tolerance than 0.3? Not used a controller before so that's going off how I assume they work (Probe detects too high temp and cuts power or a too low a temp and restores power to a separate device).
 
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Regarding the controller, could you not rely on the Hydor thermostat and just have the controller cut it off at a high upper limit, so really the controller would only kick in if it stuck on more as a fail safe with a higher tolerance than 0.3? Not used a controller before so that's going off how I assume they work (Probe detects too high temp and cuts power or a too low a temp and restores power to a separate device).
That’s what I did originally, but the Hydor’s thermostat is so sensitive that it was switching every minute or two. On a larger tank with more thermal mass it wouldn’t be a problem.
 
We used the smallest Hydor one , 200w 12mm hose, on our 50ltr tank , it worked ok, but being a bit oversized it did click on and off a bit too regularly ( clearly it switches via a relay), which in a quiet room can be annoying as it kind of resonates in its hollowish plastic case , way nosier than a standard in tank heater.

Stopped using it as concerned the relay would soon wear out and either stick off or on, would say using it with a basic protection controller like a little Stc1000 essential for long term peice of mind.
 
Looks like theres a gap in the market for an external heater for a nano tank, seems like a such a great idea. Even the thermo canisters are usually only available in the bigger sizes. If i had a massive tank hiding the heater would be less of a problem!
 
I don’t see the need for a heater in a small aquarium. If you keep your home temp around 72 to 75 degrees the water in a small aquarium will be the same as room temp. Fish and plants will be just fine. Run my small tanks this way with out any issues.
 
Is there a technical reason for using it? Or did you use it because it was what you had handy?
The principal reason is that I wanted as little equipment inside the tank as possible. It’s harder to hide things in a very small tank. So the reason is purely aesthetic.

Looks like theres a gap in the market for an external heater for a nano tank, seems like a such a great idea.
I totally agree - I’m surprised manufacturers haven’t realised that external equipment is even more relevant to nano tanks than for big ones.
 
For a small tank are the in tank heating cables an option ?

Many years ago with planted tanks , it was the standard way to lay a cable under the substrate , though in a larger tank you also needed a standard heater, if in a cold room.
 
For a small tank are the in tank heating cables an option ?

Many years ago with planted tanks , it was the standard way to lay a cable under the substrate , though in a larger tank you also needed a standard heater, if in a cold room.

I wondered about this too, and would be interested in knowing who got that to work.

To keep life simple in my Betta tank (they like it warm) I’ve got an Amazonas nano heater. It is hard wired to 25 degrees. Its’ quite tiny and relatively easy to hide. I’ve only had it a few weeks so can’t vouch for the reliability.
 
The principal reason is that I wanted as little equipment inside the tank as possible. It’s harder to hide things in a very small tank. So the reason is purely aesthetic.
I agree with that, I was wondering why the 200W model, but Dino21 mentioned that it's the smallest available, so it looks like you didn't have the option of better match of heater power to tank volume.
 
I don’t see the need for a heater in a small aquarium. If you keep your home temp around 72 to 75 degrees the water in a small aquarium will be the same as room temp. Fish and plants will be just fine. Run my small tanks this way with out any issues.

I live in England and I'm tight with the heating! Even when I put it on I set it to 18 degrees C (65F)
 
I don’t control the temp in the house the wife does. She who must be obeyed has spoken. It helps that I don’t have to run heaters in my aquariums.
 
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