What's a CL intake? Maybe I misunderstood what CL means, I thought it was just where all the flow comes from the returning water from the sump.
Typically closed loop refers to a system where there is no sump, just a pipe rigged in one way or another to pull water from the tank going directly to a pump, then directly back to the outlets in the tank. An overflow/sump makes it an open system, and I think could be a great way to run such a tank if you can get adequate flow through the overflow and sump with acceptable levels of noise.
As for the random flow, I have thought about that for my new setup. If I wanted to do it in an anemone system I'd probably rather look at something like a sea-swirl, which runs your return through an oscilating enductor. They are around $200+ which is a bit much for me, but is not much compared to some powerheads. I've had no noticeable problems with the unidirectional flow, but hard to say what benefits I might be missing. I tend to just swivel the enductor to face a different direction every now and again. Those enductors really accelerate the flow though, so mine blasts things if I'm not careful. I essentially point it into the far corner, and it seems to get some variation in flow around the tank but definitely not anything like when I used to run powerheads.
Sorry for the long reply. Basically, I think I'm never going back to powerheads on an anemone tank! :lmao:
Appreciate you sharing your experience. With some of the newer high volume overflow systems and a well designed sump perhaps the PH or CL would not be necessary.