Reducing 2028 waterflow by 50%, is it practical?

[Rupert]

I have this small 2ft tank that I want to use a chiller on and should use a suitably sized filter, but would like to use a Eheim 2028 instead as I have two already and would like the redundancy of having a third one around the house. Secondly as the tank volume is small [50lts] the water volume in the canister filter would be useful.

Question: Would reducing the water flow purely by having an external hose / outflow constraint damage the filter motor or impeller? Or this not a good idea at all?

Damaging the motor I see as bad, as this would lead to unreliability and is something to be avoided.

Any suggestions welcomed

[vinz]

Eheim FAQ says you can, but only restrict flow at the filter outlet and NEVER at the filter inlet.

Eheim has several models that have built in flow control, and they mechanically restrict flow at the filter outlet and not via electrical control of the motor.

Given Eheim's long term reputation, I'll take it that it is alright.

[tawauboy]

should not be a problem.
as long as you restrict the outlet flow.

[BFG]

Either you restrict it at the outlet flow or push the water through a external reactor into a chiller into the tank with long hose.

[Rupert]

Thank Vincent, Thomas & BFG, for your quick responses; I was worried that I could damage the filter. Now I feel a little more comfortable going for another 2028 and restricting the outflow… now just have to get the 2028.

[Rupert]

I stepped down the outflow piping from 16/22mm to 12/16 then to 9/12 mm piping, the water flow to the tank didn’t seem reduced by much at all, rather the intensity of the water coming out from a small aperture [9/12 Eheim Lillie pipe] seemed greater.

While it is possible to reduce the flow directly by adjusting the Eheim adaptor lever, I found say the best way to restrict water flow is to have a tap that one can progressively close / reduce the outflow to the tank to a point that is desirable.

[valice]

By reducing the size of your pipe, the intensity of the flow will definitely be greater and not smaller... The force is now concentrated in a smaller spot and so the pressure of the water is greater... using pressure = f/a, the force is the same, your area of pipe is smaller, so pressure/intensity of water becomes greater...

You rather that you use a single long 16/22mm pipe... The flow will reduce by the time the water reach the opening...

[albert]

FYI, 2028 has built in flow control mechanism. Please refer to your user manual for how to reduce the flow rate. Basically is thru the latch thing that you used to remove the hose attachment.

[Rupert]

FYI, 2028 has built in flow control mechanism. Please refer to your user manual for how to reduce the flow rate. Basically is thru the latch thing that you used to remove the hose attachment.

Hello Albert, I understand that there is a flow control mechanism called by Eheim an “adaptor lever”, but find that rather crude. In the end a chiller was chosen that had taps that offered a more refined approach.



I would expect that any type of tap would work.

[BFG]

Rupert, I just realised something. There was a reefer who used a 2128 for a nano but he swapped the impeller from a 2128 impeller to a 2222 impeller. I will look for the thread (ReefCentral) and post it here. Gosh, how could I missed that? Stay tuned!

[BFG]

Here's the link-

http://www.reefcentral.com/forums/sh...&pagenumber=11

Hope this helps!

[Rupert]

Rupert, I just realised something. There was a reefer who used a 2028 for a nano but he swapped the impeller from a 2028 impeller to a 2222 impeller. I will look for the thread (ReefCentral) and post it here. Gosh, how could I missed that? Stay tuned!

Mohamad, I actually thought of that but wasn’t sure of the sizes, I even thought of trimming the impeller “wings” with a pair of pliers, but common sense prevailed, as I was concerned about balance and ruining my investment.

To put this effort in context my 2 foot tank’s water content with substrate/rock etc is 33 liters so the extra 9.5 liters in the 2028 and 1.5 in the chiller make a big difference

[Rupert]

Here's the link-

http://www.reefcentral.com/forums/sh...&pagenumber=11

Hope this helps!

Good Link, he was going to do the same... cut down the impeller blades!… and he owns an electric drill! I might go out and get a 2028 impeller and smaller model and try this.

Thanks again for the link

[BFG]

Obviously, going from a filter with an output of 132gph to one with an output of 280gph is a pretty big change. Especially when the tank is only 2gals . I had planned on cutting down the impellor blades on the new filter to reduce the flow, but fortunately eheim - bless their hearts - saved me the trouble. Here you can see the 2128 impellor wearing the blades from the 2222 - a prefect fit!

Rupert, he uses the 2222 impeller in the 2028 ( 2128 ). No mods at all!

[Ibn]

You guys can also try another method that won't require modifications to the filter. Add some 90 degrees into the piping will cut down the flow considerably.

Each 90 degrees is equivalent to about 1' of head.