# Hydor inline heater -to much for a 20?



## thaerin (Dec 12, 2004)

Hey peeps,

I've been hearing great things about these inline heaters and was thinking of getting one. My tank seems to fluctuate in temperature quite a bit, sometimes by as much as 4-5 degrees. When I check it this time yesterday, it was 78, today it's 74. I know every tank fluctuates some but is that a little to much change? I keep the thermometer on the corner diagnol from the heater to give an idea of entire tank's temp.
Not to mention, I'd really love to get one more piece of equipment out of the tank.

Small problem though. The usual rule of thumb I'm told is about 5 watts per gallon of water, so for a 20 Long tank, it'd be roughly 100W heater, which is what I have. But the size needed also depends on the difference between the room temp and the tank temp. We keep our house fairly cold in general, as we feel it's easier to get warm then get cold. Highest we set the temp during the winter is 70. So maybe I need a stronger heater?

The smallest of the Hydor's is rated at 200W and recommended for a 26-48 gallon tank. Is this going to be to much of a heater for my tank?


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## [email protected] (Sep 26, 2004)

i use the hydor for my 20 gallon. Having a bigger heater is no problem. It's thermostat will keep the temperature of the tank constant. A bigger heater just means that the heater won't be as stresssed.


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## jcolletteiii (Jan 30, 2005)

I have a 200 watt hydor on my 29 gal, and it maintains exactly 78f all the time. The extra wattage will heat the water more quickly. These heaters are awesome, and no heater in the tank, which IMO is hte best part.


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## titan97 (Feb 14, 2005)

You also have to take into account that with the inline heaters, the transfer of energy is more efficient. Instead of having the water passively heated by your old immersion heater, you now have active heating with the inline heater. This will allow you to use a smaller heater than what you need now. And everybody else is correct, there isn't really a heater that is too big. As long as you set the thermostat correctly, it should be fine. 

-Dustin


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## hoppycalif (Apr 7, 2005)

*Heater size*

I am very nervous about oversized heaters in general. When you have an oversized heater, and the thermostat sticks, you have a pot of fish stew pretty rapidly. So, I have always kept the heater undersized. It doesn't harm it in any way that I know of to run continuously, even if it did that. On the other hand, every time the oversized heater cycles on and off it is getting closer to the day the thermostat switch contacts fail.

But, enough grim comments! Now for a question: does the Hydor heater have any effect on the filter outlet flow rate, assuming it is in that water line? I would like to use one on a 29 gallon tank, but I will already have my CO2 reactor in that line and I don't want to add so much water resistance that the filter flow drops too low.


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