Can we talk FLOW?

[DmitryB]

Let's talk about FLOW! Flow is more difficult to figure out and set up than lighting. I mean with lights you buy a light with enough power for your set up, pick the light preset you like, and go. Pretty much plug and play. But not flow. Flow is a monster to tame. A million things to consider. Especially when Low, Moderate, and High are kind of meaningless terms. They can mean anything. As a lover of classical music I think of it as musical tempo markings. Andante will mean different things on a different day to a different conductor, which is why Beethoven's Fifth will sound different every time. So it is with Flow. How do you make everyone in the tank happy? Fish, but especially corals. This one wants low, that one wants high, that one is Goldilocks, doesn't know what it wants. And neither do we. Oh and then there's sand.

So how did you or do you figure out your flow? Do you acclimate your corals to flow as well as lighting? How long do you give a coral before you decide "This isn't the right place for it."

I'm currently trying to figure out flow of ray 170 gallon. I have two Orcas 6105 on the back corners + a ReefWave 45 sending a sheet of flow across the surface. (I'm ignoring the return.) I'm trying to decide how high to raise the Orcas. Do I create high flow in the upper half of the tank where SPSs will be located and leave the lower half Moderate/Low for Softies and LPS? How do you arrange your powerhead? What's the secret sauce to flow?

 

[KrisReef]

I don’t think there is a simple answer. As you noted, different corals want more or less water movement, while a pump or a return nozzle are somewhat limited in the output they produce.

Our ability to move water around a tank cannot compare (or replicate) the continuous water changes that coral on a reef experience.

Current in our tanks blows compared with natural situations that will corals experience.

I need to acid dip my gyre and wave makers today, something that nature doesn’t have to do to keep the water moving. The movement is key for respiratory function, for feeding and removing metabolic energy.

 

[Biokabe]

Flow is one of those things that, if you can really unlock it, I think it can do great things for your reef. But it's easy to overcomplicate it, it's easy to overengineer it, and it's easy to do it wrong.

For myself, I try to have a lot of random flow coming from different sources, and I use the rockwork to create areas of reduced flow for corals that like more peaceful flow. I don't know enough about flow to design the "perfect" flow for everything, so whenever I add a pump, I just figure out the max rate, select the "random" setting, and put it where I think it'll do well. I currently have four powerheads in my tank and flow seems to do well for everything, but time will tell.

 

[mfinn]

I'm currently trying to figure out flow of ray 170 gallon. I have two Orcas 6105 on the back corners + a ReefWave 45 sending a sheet of flow across the surface. (I'm ignoring the return.) I'm trying to decide how high to raise the Orcas. Do I create high flow in the upper half of the tank where SPSs will be located and leave the lower half Moderate/Low for Softies and LPS? How do you arrange your powerhead? What's the secret sauce to flow?

It sounds like you have the equipment in place to create a high surf zone everywhere. ( ignore the return is good)
It also sounds like you have formed a plan.
Go with your ideas and be willing to modify them based on results you see happening real time.
Only you with your rock placement and coral placement can really make the right call.
Picture in your mind how you want the water to flow. Flowing clockwise or counterclock wise, or just crashing into it's self in the middle.
Set the powerheads in the appropriate spots to make you plan work.

I don't have a specific answer except to try it one way, if that doesn't work be flexable.