Having proper water flow in your reef aquarium is extremely important  to your reef’s health, especially when dealing with corals.  It is so important that I would rate it up there with feeding, lighting and skimming.  After all, proper water flow delivers food and removes waste from sessile organisms in the reef aquarium.  Proper water flow also exchanges oxygen and keeps detritus suspended in the water column.

Getting the right type of water flow is often difficult to achieve in the reef aquarium because of all the options that are presented to us.  On top of all the pumps, wave boxes and diy closed loop systems that you can utilize there is still the matter of placing this equipment in your reef aquarium so that you can reap the full benefit from it.  Keep in mind that live rock and other obstacles in the aquarium can prevent proper flow throughout the reef aquarium if not set up correctly.

So what are the different types of water flow and how do us reef keepers use them?

Pretty simply there are two types of water flow for the reef aquarium that you should be concerned with. They are Laminar and Random.  If you search on any online reef aquarium forum you may be able to find more in depth but not as practical ways of creating water movement.  I say “not as practical” because most reef keepers will not be able to recreate these different water flow options as easy as the two mentioned above.

Laminar water flow is generally the easiest flow to create in the reef aquarium.  laminar simply means one direction movement of water, as you probably guessed by now most submersible pumps and powerheads will produce laminar water movement.  Laminar can get tricky, since it is a constant jet of water in one direction you will not be able to place corals directly in front of this stream.  Most corals will not be able to last the powerful water jet and there flesh will eventually erode off there skeletons if exposed for long periods of time.  Many reef keepers utilize powerheads and submersible pumps but do it in a fashion where it is less abrasive on corals,  which brings me to Random flow.

Random water flow in the reef aquarium is hands down the best easily obtainable way of re-creating water movement similar to that of the natural reef.  It is simply obtained by using laminar flow (powerheads, pumps etc..) against either obstacles such as the glass of the aquarium or against other laminar flow.  Since there is no right way to create random flow in the reef aquarium because all reef aquariums are different, it is up to the reef keeper to try and test different ways to see which one is right for the aquarium. I personally like to direct two powerheads against one another (one on each side of the tank opposite of each other) to create this type of flow. I will then take another one and point it at the front pane of glass.  The possibilities are endless with this type of water flow since there is no right way of doing it.  Instead of using powerheads you may want to try a closed loop system which involves a large external pump and some diy (do  it yourself) plumbing to avoid unsightly powerheads.

Which ever way you decide it is best to make sure that you don’t have any “dead spots” in the reef aquarium, dead spots are simply just spots in the aquarium with little to no water movement.  These dead spots are where detritus will accumulate and if not removed can cause some problems with your reef aquarium’s water parameters.

So how do I know if my water flow is adequate?

Make sure that you have a good amount of movement in your aquarium, furthermore you should be able to create flow that will make your coral polyps extend and move around randomly.