Why would this damage the filter? Doesn't the flow get restricted over time as the media clogs up anyway?

 

Restricting water that is flowing into a canister filter could damage it, as the amount of water that is being pumped out might be more than the amount of water that is flowing into the filter via siphoning.

 

I do not see the above case happening unless the fish tank runs dry.

Regardless, just go with 13" on both ends. Both Eheim and Fluval mechanically change the inflow / outflow diameters with ball valves on their adjustable flow models.

v3

 

I would take an educated guess you are correct. On top of that, I have had some seriously clogged up inflow pipes to where it effected the flow and no damage to filter so that's my experience. I also be my lily pipe is more restrictive than the stock inflow.


I actually don't think I have actually seen damage attributed to any of this stuff in the entire time I have been on this site so though it may actually worry me a bit, I would imagine I would have seen a few examples of failure by now.

 

brilliant thanks everyone going to go with 13mm nano inlet and outlet and will have to but a heater in either 13mm or 17mm think will go with 13mm

cheers again thanks for help will hopefully get journal started soon

 

I know this is a month old post. I was wondering if you decided to keep the 13mm pipes. If you want 17mm pipe, and you don't mind spending the cash, you can take a look at the Cal Aqua Influx X3s. They are for sale at Green Leaf Aquariums (http://greenleafaquariums.com/products/cal-aqua-labs-influx-x3s-17mm.html). Not sure but I think most people have problems with the inflow being too long with 17mm pipe. The out flow probably is not much of a problem as it is significantly shorter inside the tank than the intake.

 

Restricting the flow to a magnetic impeller pump will not hurt it in any appreciable way. The working of the surrounding coils are not impacted by whether the impeller is turning or not. The pump can not pump more water than it takes in unless it has an air leak in it some where. You can block the flow completely and the impeller will continue to turn with no appreciable damage. I say appreciable because severely restricting the flow you are putting abnormal loads on the impeller which can cause abnormal wear between it and its axle pin but this would only show up over long periods of time and would only reduce its life by a bit. Only by running it dry over a period of time can you damage it and only then because the coils begin to overheat and the axle pin wears down quickly.