Internal filter is large for my tank

[prateekgs555]

I have a sunsun internal filter which filters at a rate of 600litres per hour but i am having a tank of 46.6 litres .acoording to calculations i should have bought 279.6litres per hour filter .my tiger barbs seem to be stressed by filter what can i do to reduce it .??please help .

 

[praisid]

Try attaching a regulator to the air inlet. Dunno if it works but if u partially obstruct the air inlet the flow tends to decrease