Just a few thoughtsââ"šÂ¬Ã‚¦
Turnover, IMO is not the best way of describing the water motion of a tank. It may be useful for filtration, (ie sump to tank) however, its effect is limited in the tank itself (a 3000 LPH pump aimed into a wall of a 300 Ltr tank, has 10x "turnover", but is fairly useless for the coral. etc etc).
IMO whats more important is the velocity and variability of the water motion.
-Surge (the Wavebox/Surge tank -back and forth
-Turbulence (Sea Swirl, Tunze Stream on Random) -just the Random Swirling of the water
-Laminar flow (return, normal powerhead) uni-directional flow (some turbulence is caused by Laminar Flow, but generally not much)
Whats ââ"šÂ¬Ã…"œbest for the Coralââ"šÂ¬Ã‚Â? Well, that depends on where the coral is collected, as they all have special flow requirements.
For my sps holding tank (nano 18g) I use a Tunze 6060, Eheim 1262 CL, and some other Ehiems,
Anyway. Total "turnover" is about 170x/hr. High veolicty for the sps sites. No fish.
We need to remember that coral use the flow for:
-Bringing Food, and flushing wastes
-Gas exchange (CO2/O2)
JMO!