Planted Tank Guru
Join Date: Jul 2010
Location: Huntington Beach, CA, USA
A cheap way to restrict the flow is to add adapters and make the water go through a smaller section at some point in the output line. Think of it as the same as traffic might flow. If you have a four lane highway go into a two lane and back to four, traffic slows. Water works much the same. The disadvantage of this way is that it is not easy to adjust and may take some guesswork to get the correct size for the flow you want. But then you can normally return the extra parts you bought to experiment on flow.