Inline kit - Heater and Diffuser

[Norfolk180Rio]

Heater
I am looking at the hydor inline heater...Obviously! But to get a tube diameter of 16mm that wont slow the flow I will need to get the 300w model. From the info for the two sizes it kind of suggests that this will be too powerful with my 180L tank.

Here is the info:
http://www.thegreenmachineaquatics.com/ ... %20Heaters

Basically, will I experience overheating with the 300w model?

Diffuser
I am looking at the Cal Aqua inline diffuser. Has anyone had any problems with back flow of water towards the CO2 cylinder when the CO2 is off during the night when using the cal aqua inline diffuser? I know you can put a valve in but this would be effective enough when having 1200 or so liters of water passing through per hr?

Thanks for your time guys and girls!

 

[ceg4048]

...Basically, will I experience overheating with the 300w model?

Why should this happen? Doesn't the 300W heater have a thermostat? Theoretically, a 300W heater should be able to heat the water twice as fast as a 150W heater. When the selected temperature is reached the heating element shuts off. This works exactly the same whether it's a 10W heater or a 1000W heater. I don't see where the problem is.

I am looking at the Cal Aqua inline diffuser. Has anyone had any problems with back flow of water towards the CO2 cylinder when the CO2 is off during the night when using the cal aqua inline diffuser? I know you can put a valve in but this would be effective enough when having 1200 or so liters of water passing through per hr?

You need a check valve on the upstream side of ANY external diffuser. This is not optional, otherwise you will flood the downstream side of the solenoid. A good quality metal check valve costs about 12 quid. Buy one, install it, and this becomes a non-issue.

Cheers,

 

[Norfolk180Rio]

Thanks for the quick reply.

Cool. That answers both of my questions.
The reason I asked about the heater was because it was rated to a range of tank volumes. I understand what the thermostat does. I just wanted to check!

As far as the diffuser / valve goes. That clears up any worries I had.

Just finalising my new filtration, flow, heating, diffusing set up!
Ehiem 2080, Hydor 300w inline heater, Cal Aqua (17mm) inline diffuser.