Define Flow for SPS

[Batt]

Ok flow is good for sps but thay don't like constant flow . The flow I have in my take is crazy the water looks like its going to come out of the tank, but the sps love it . I only use tunze pumps had vortexs pump but to me there junk . Does not give me the turbulence I need to keep my sps happy at all . I have all my 2 of my pumps on wave motion and the others in pulse mode every night at lights out the pumps shut off . only one pump stays one till lights are back on. sps love turn over at 100x and more...... The key is not flow but movement in the tank......

 

[mattgreene22]

jtomasi - post a pic of your rockwork (front, and above if you can) and it may be helpful for powerhead placement advice. Also, look into gyre tanks if you want to alternate between two primary powerheads....the gyre concepts around alternating currents to also get turbulence may be helpful. Such as in this article: Feature Article: Water Flow is More Important for Corals Than Light, Part V — Advanced Aquarist | Aquarist Magazine and Blog

Also, if that Tunze video is the same one I saw in a local forum it starts off with narration and ocean reef footage. Somewhere in there they mention the normal meters/second flow rate of laminar flow in lagoons and elsewhere...just can't remember what those numbers are off hand...but think it was from dana riddle research

 

[mcarroll]

Thanks again Matt. So what you are saying is run the right pump for 4-6 hours, shut it off and run the left pump for 4-6 hours?

I actually decided to go bare bottom and will put in a DSP in my sump later (maybe). Right now I set it up so the Hydor 750 in as low on the tank as possible to push the detritus to one corner where I set up a maxijet to pull it off of the bottom glass and push it up towards my overflow . There is a small area that collects detritus but will be easy to clean once every couple of weeks when I do water changes. Per your suggestion, I will keep this setup but add another pump on the right side of the tank (opposite the current left pump)

Thanks again, Ill post pics when its all done.

Three cheers for bare-bottom tanks! [Yay! Yay! Yay!] Lol...

And on the pump cycle timing and strategy - you got it right.

If you decide to try a deep sand bed, put it in a container that you can yank out easily - a tray or something. When it goes "south" it won't be such a PITA to get out....shopvac style. (I don't recommend them, personally, unless that was part of your idea in setting up the tank in the first place.)

I think you should try your existing powerheads on the side-glass as recommended - above and in front of your rocks, with a clear shot across the tank - to see what it does for you....might find that's all your need. (This and small variations on it got my SPS tank by for the first few years before I had to add a third pump due to coral grow-out.)

Just for the record and to repeat, most corals (no exceptions come to mind) do appreaciate laminar flow as all reefs experience laminar flow every day with the ebb and flow of the tides. This is the predominant form of flow on many if not all reefs....the only form of flow on some reefs. I've seen this natural flow rate estimated to be around 20,000 gph. So, unless you've (e.g.) aimed a MaxiJet directly at a coral from 10" away (wrong kind of pump...and you don't aim at the coral), you're unlikely to make any corals unhappy with laminar flow, especially when it's set up in "tide simulator" fashion.

Wave action (which applies movement/momentum to every molecule of water in the tank) is the second type of flow to consider adding - but distinctly less important. (I've never added it, FWIW.)

"Turbulence" isn't the same as wave action - it's the opposite of laminar flow (laminar flow + obstacle or opposing force = turbulence) and something you really want to avoid where possible because it literally kills water movement. (It happens natually, so it's not possible to have no turbulence...no need to worry about that even if you wanted to. Further, all propellor-based powerheads induce a certain amount of turbulence just in the way that they push water. Watch the vid for details!)

Best of luck! Let me know how the experiments go! :)

-Matt