Turnover rates & waterflow

[mark]

Between the return and CL I'm turning my display by 30+ times and can't see wanting more. Running a mixed reef so along with the SPS I've got a clam, LPS and soft and getting difficult to find areas of low/mod flow for them.

Little side note, bearing went on my CL pump so had it shut down for about a week. Turn over dropped to about 7 times and even after the week, polyp extension on the SPS was about the same as with the CL. Can't comment longer term or effects on growth.

[Myka]

I prefer 6-7x per hour turnover through the sump.

I like LPS corals, and they don't like high flow from the powerheads. BUT, the turnover rate from powerheads is VERY different if you're using propeller powerheads (like Tunze and Koralia or MJ mods). You can go about 2x the turnover from propeller PHs versus impeller PHs.

I like about 10x per hour turnover from impeller powerheads, or about 20x turnover from propeller PHs.

[midgetwaiter]

Taking pump specs at face value I have 68x in the softie tank and 46x in the LPS tank, both are BB. Actual flow I estimate at about 75% of those numbers.

You just can't have too much flow.

[andresont]

In the display tank i have 90x times turn over Not counting the Wave Box (if I added the g/hr correctly) . But this is still nothing compare to what is going on in the ocean imo.
Corals are happy including touchy LPS (Gonioporah).
The return rate is very slow only like 90 Gal /hr (Eheim 1250@5 feet head)
the reason is that my skimmer is not in the sump so this is just to get cheato growing and to hide heater etc.
However even if I had my skimmer in the sump I still would have slow flow in order to get my skimmer time to process the waste.

[Myka]

I don't know how you guys can have such high turnovers with LPS...?? As soon as I add another small powerhead I get poor polyp extension no matter how I try to arrange the powerheads. I just re-did my entire tank and I didn't have any powerheads in it for 24 hours and had the best poylp extension on the LPS I've ever had. I added my Koralia 2 which is blasting straight onto my SPS and only very indirectly hitting my LPS, and the poylp extension is definately a bit less on the LPS, although obviously my SPS are happy 'as a clam'.

[ron101]

Originally Posted by Myka

I don't know how you guys can have such high turnovers with LPS...??

Because those numbers are next to meaningless.

Too high of flow velocity at the coral in question is what will cause problems. High flow rates can be achieved at various flow velocities (eg large prop/slow revs vs small prop/high revs.)

I think you can have too high of turnover in a tank. Tanks are not comparable to the open ocean where the cross sectional areas of ocean currents are orders of magnitude larger than the 2 square inches of a tunze stream outlet...