Water Flow Control of EHEIM

[EddyTing]

Hi, just a question. Many EHEIM canister comes with a water flow control knob. If we were to lower the water flow with it, example it has a capacity of 800l/hr flow reduced to 400l/hr, would it cause any side effect on the canister itself in long term?

[bossteck]

From what I read, there will not be any side effects if you only limit the flow on the return output side (ie, side from canister to tank)... unfortunately, I can't seemed to recall where I read that.

[eviltrain]

for my tanks, i limit the output of the canister. so far so good.

[EddyTing]

Hmm...thanks for the input guys...appreciate it.

[barmby]

I will not limit the flow because the motor is trying to work even harder to overcome the 'bottleneck'. In the long run, imo, it is not healthy for the pump

[tofubox]

i agree, try not to limit the flow, it will damange your motor in a long run.

[EddyTing]

Oh...seems like another point of view...
Actually, I do feel that the head a slightly hotter than free flow though...

[tawauboy]

you can control the flow rate of your filter without harming the filter.
eheim filters are is designed to handle reduced flow rate operation else eheim will not advertise 'adjustable flow rate' feature.

the pump head may feel slightly hotter due to te reduce flow rate (lesser heat removed by water). this is normal.

[madscientist]

i dont think reduced flow will increase the rpm of the impeller. there is nothing to measure the rpm of the impeller (electronic feedback). a drill with electronic feedback will attempt to increase rpm to provide more torque to maintain speed. but then the impeller is so-called free spinning. even if the impeller is totally stuck, the pump head will not spoil if there's an alternative way to remove the heat other than the flow of water provided by the impeller.

[EddyTing]

thanks tawauboy...you've got a point there...
and madscientist....that's for the technical explanation too...hahaha...
Looks like it's getting more interesting...

[Shadow]

i dont think reduced flow will increase the rpm of the impeller. there is nothing to measure the rpm of the impeller (electronic feedback). a drill with electronic feedback will attempt to increase rpm to provide more torque to maintain speed. but then the impeller is so-called free spinning. even if the impeller is totally stuck, the pump head will not spoil if there's an alternative way to remove the heat other than the flow of water provided by the impeller.

Sure can, measure the back EMF although I doubth eheim will do that except maybe pro3e model

[madscientist]

i know can, haha. otherwise how the drills do that? i don't think there's any benefit in doing that. if there's electronic feedback in the pump head, the increased power to attempt to increase the flow rate can actually break the blades of the impeller. if you notice, the impeller blades are thin, the reason is to minimise weight so it takes less power to spin it, effectively able to spin faster while reducing power consumption. which means the blades can be broken quite easily. i think eheim rather has the impeller stuck till the thermal protection kicks in. if electronic feedback is in, eheim will be more likely be selling impellers than pumps.

[barmby]

Well Eddy,

tawauboy is experienced while madscientist is a researcher or scientist in NUS or something like that I am not too sure. But they are the top guys.. listen to them .. heh..

[EddyTing]

Roger that Barmby...I will...thanks.