I'm planning a new tank (approx 150 US gallons). I like the idea of an in-line heater installed on the inline of my canister filter. One model I've found is 300W. Is that enough to heat that much water? The ambient temp in the room is typically around 68 degrees / 20C; warmer in the summer. Other considerations for inline heaters?

I'm confused on the wattage - assuming bigger is better? If I go with a traditional in-tank heater, would 500W be better than 300W?

thanks as always

In line all the way. if you have in-line heaters, the water is heated as it passes through the pipework, rather than trying to heat the whole tank by putting the heat inside the aquarium. I am heating a 300 gallon aquarium to nearly 29° with 600 W of heating. I think the only drawback may be rather like using a small heater in a large room, it has to work that little bit more to heat such a large space.if I was you, I would go for the 500 W. You can then set it at 27°C -- 28°C, which ever you want and you will find that it will only come on if the water drops below that temperature.

thanks - I also like the idea of less things hanging inside the tank. what brand is yours in the photo? so far the only one I've found is this

www.drsfostersmith.com/product/prod_disp...369&pcatid=11369

It's only 300 watt. I suppose I need to make sure the diameter fits my tubing? Are they prone to leaking? I can't think of any other downsides.

Hydor are a pretty good make , I don't think you'll have any problems with it leaking.I reckon 300 W will heat your tank just fine.