Filter Flow - Reducing It.

[breamster]

Hi All,

Will reducing the filter flow have a noticeable effect on the efficiency of my filter?

30l tank. 4 galaxy rasbora (more when I find some), 7 cherry shrimp. Filter is a hob filter if that makes a difference, rated at 250 litres per hour but I don't believe it! Lots of plants.

Thanks.

 

[Honeythorn]

Not as long as you don't reduce the flow TOO much. You might want to try wedging a piece of small grade( small holes) filter sponge just behind the gap where the water flows out. The sponge will also harbour a little filter bacteria too.

 

[bitteraspects]

im not sure what you mean by "reducing the flow".

if you are diffusing the output of the filter, it will not cause any problems, however if you are blocking up the intake to reduce the flow, it will cause problems. the extra strain put on the impeller will cause it to burn out quicker, and even if it does not cause immediate problems, it will greatly reduce the life of the filter.

 

[OldMan47]

Welcome Breamster. The filter flow of a filter is not as important as the quality of the bacterial colony on the media in terms of biological filtration. For decent mechanical filtration, more flow is actually better. I use my filters mostly to take care of bioload so I seldom worry much about reducing flows to suit a fish. When you decide to throttle the flow of a filter, it is far better to do it on the return path than on the inlet end. As Bitteraspects said, throttling the inlet can cause damage to an impeller but throttling the return can be done to a large degree before it impacts the impeller at all. You would need to throttle so much that the water in the impeller actually started to heat up from the mechanical friction of the impeller before it would harm it throttling that end.

 

[breamster]

Hi,

Thanks for the replies and the welcome!

I've adjusted the filter using a knob on the top rather than improvising something.

The filter I have (if it helps) is...

Filter Link

It is the Niagara 250.

Plants and inhabitants do seem a little more settled with the flow reduced.

Cheers.

 

[OldMan47]

Glad to hear things are working out for you. When you have a built-in throttle device, I always assume the manufacturers knew what they were doing on their own design. It may be a poor assumption but you have to trust something somewhere or go all the way back to the first person who learned to make fire and work your way forward.