Hydor external heaters

W

wynn

experienced noob
Nov 25, 2004
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0
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Just thought I would share this info for you guys. A couple of weeks ago, I installed one 300 watt hydor external heater on my 120 gallon tank, replacing two 300 watt submersible heaters. Since installing it, the temperature has been a steady 82F (the weather in my location has fluctuated anywhere from 35-78F). I guess the 5 watts per gallon doesn't apply to these types of heaters. I also have been using one on my 75 gallon tank for a couple of months now and haven't had any problems with it.

Anyway, I just wanted share this info in case anybody was wondering about them. It is really nice not having two submersible heaters in the tank now, and also not having to worry about the larger fish breaking the heater.
 
Thanks for the info wynn! I've seen them in catalogs and thought about them. Does it hinder your flow at all?
Large tanks (large volumes of water) retain heat much better than smaller ones, so once you have the tank up to temp, it doesn't require as much to keep it there.
So now that you only have one heater...aren't you worried about it failing and not being able to see it?
 
I also have a 300W Hydor ETH on my 72G its been very stable and I am quite pleased with it. I check my temp twice per day so I think I would know very quickly if it failed. Its been running for 3 months so far and its been ok. I will of course post back if it was to fail....
 
beviking said:
Thanks for the info wynn! I've seen them in catalogs and thought about them. Does it hinder your flow at all?
Large tanks (large volumes of water) retain heat much better than smaller ones, so once you have the tank up to temp, it doesn't require as much to keep it there.
So now that you only have one heater...aren't you worried about it failing and not being able to see it?
Click to expand...

No reduction in flow at all. I'm pretty sure it's a straight shot through the heater, though I have to admit that I didn't look all that close to it before hooking it up. :D Yes, I have thought about the one heater failing...I may end up getting another one in the future to give me peace of mind, but it's nice to know that I don't really need it.
 
Thanks for the heads up on a (so far) quality reputation for a newer heater! I, too, have had my eye on this baby!
 
I almost bought the 200w Hydor external heater today at Big Als . . . almost. I guess I'm in a don't fix it if it aint broken situation with my current setup (although the internal submersable leaves a bit to be desired when it comes to looks). Especially when the heater costs as much as it does. Sigh.
 
I have to say that my own experience with a Hydor-Theo heater in an external Pentair module on a 55 gal tank bears out beviking's conclusion ... that an external module heater which is unable to actually sense tank water temperature will NOT be a problem on large tanks ... because the glass surface area versus gallons ratio is low and the thermal mass is high. However, when tank size gets smaller, the glass surface area versus gallons ratio gets higher and higher and the thermal mass gets lower and lower, leading to the potential problem of tank temperature changes despite a constant water temperature coming out of the external heater module.

On my 55 gal tank in a non-air conditioned room, the tank temperature would swing up to 4 degrees between nighttime and afternoon as the air temperature of my room swung 15 degrees. When I moved the same Hydor-Theo heater directly into my tank (this heater has the same PTC plastic heating element that the Hydor module uses, but it's housed in a conventional submersible glass tube with top thermostat dial), my temperature swing went down to essentially nothing. However, since I have now added air conditioning to the room which stabilizes air temperature and therefore the heat loss through my tank glass, I could probably move my Hydor-Theo heater back into my Pentair module without the same problems I experienced earlier.

PS I opted to go with the Pentair external heater module because it's super easy to take apart and clean, and because you can simply shove a new glass tube heater through the top seal if your old heater ever dies. Also, there's lots of room to throw in bio-balls around the heater.

pentair4.jpg

~
 
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