• You are viewing the forum as a Guest, please login (you can use your Facebook, Twitter, Google or Microsoft account to login) or register using this link: Log in or Sign Up

Flow direction


3 Jan 2011
To combat algae I've recently increased the flow in my tank by adding a Hydor external pump, plumbed in to a second spray bar.
In the diagram, my EX1200 feeds the red spary bar and the Hydor pump feeds the blue one.

(NB Not to scale: the tank is about 2'6" deep, 1' back to front, and 3'6" wide)
I've got a tap downstream of the Hydor to reduce the flow to a sensible level, but I think it's still troubling my surface dwelling fish.

So I'm thinking about adding some more holes to the Hydor's spraybar to point downwards as well as across the tank.


I've never run a powerhead of any sort before, so can someone confirm that this isn't a bad idea?
Last edited:
The reason why I would say is because you could effect the flow of the red spray bar.
What you could do is shorten the red spray bar to half of the tank and the other half you could use the blue spray bar as in your diagrams. Therefore you will have the same direction of flow. You will not be disturbing the flow in any way.
It's a long time since I sturied any fluid dynamics (and even then I skipped a lot of lectures) but with the shape, size and hardscaping of my tank, I'm not convinced ideal flow paterns are a realistic hope. There are just too many potential areas where flow is hampered.
(BTW, whilst the hardscaping is still like this, the plants don't look nearly as good, there's a whole lot more algae, and the spray bar is now properly supported.

In my more circular tanks my pentagon and hexagon... If you have opposite flows like suggested it causes issues with filtering... Its best to keep a circular flow pattern with all filters and power heads flowing in the same direction.. This way is the best way to get debris in the filters inlets and keep tanks cleaner.