In the D5 Next owner's manual, Section 5.3 states that the Fan header can be configured to connect a flow sensor. The compatible products listed are:

Flow Sensor with 5.6mm nozzle - #53061
Flow sensor "high flow" - #53068
Connection cable for flow sensor - #53027, #53100

I searched the Aquacomputer Shop and Support sites for these part numbers. #53061 and #53100 do not appear on the Shop or Support page.

#53068 does not come up on the Shop page if typed into the search box but does appear on the Support page as "Flow Sensor High Flow" which downloads a 1 page manual that lists 2 connection cables - #53027 and #53212. Both cables have the same 3-pin while connector on one end which I think plugs into the High Flow sensor. The other end is either a 3-pin fan connector (#53027) which I think plugs into the Fan/Flow header on the D5 Next, or a 3-pin pico-blade connector (#53212) which plugs into the Flow header on a Quadro, Octo, Vision, or Farbwerk360.

My questions are:

Are AC part numbers #53061 (Flow Sensor with 5.6mm nozzle) and #53100 (some type of cable) listed in the D5 Next owner's manual discontinued?

Is the High Flow Sensor #53068 a current product or has it been replaced by the High Flow 2 (#53292)?

Is the Fan/Flow port on the D5 Next, in Flow mode, only compatible with the High Flow sensor #53068, using cable #53027, or is it also compatible with the High Flow 2 (#53292) and the High Flow LT (#53291)?

If the Fan/Flow port on the D5 Next is compatible with the High Flow 2 (#53292) and the High Flow LT (#53291), does it use the very complicated looking cable (#53291-3?) that has what appears to be a 6-pin connector on the flow sensor end and a breakout to 4 different connectors on the other end (PICTURE)

What do the 4 different connectors on this complicated cable plug into? The larger beige connector looks like it would plug into the Fan/Flow header on the D5 Next. The small white connector looks like it would plug into the Flow header on a Quadro, Octo, Vision, or Farbwerk360. What does the black 2-pin and small white 2-pin connector plug into?

Can a High Flow Next (#53293) be connected to the Fan/Flow port on the D5 Next or does the USB connection replace this older architecture? The only headers on a High Flow Next that could possibly be used are Signal and Aquabus headers.

Thanks in advance for any clarification.

Thank you for the clarifications. I guess the D5 Next owner's manual section 5.3 is just out of date.

Regarding the HF-2 and the HF-LT, I think the included cable is the complicated one with a 6-pin connector at the sensor end and a breakout to the following on the other end:

a "regular" 3-pin fan connector (to D5 Next Fan header)
a pico-blade 3-pin connector (to Quadro, Octo, Vision, Farbwerk360 Flow header)
a "regular" 2-pin temp sensor connector (to mobo Temp header)
a small white 2-pin temp connector (to Quadro, Octo, Vision, Farbwerk360 Temp header)

The HF-LT does not have an integral temp sensor so the 2-pin connectors on this cable would be inactive with the HF-LT. This all makes sense. The only part that is unclear is the wiring of the 3-pin connectors. The "regular" fan connector gets Red, White, and Black. The pico-blade Flow connector gets Green, White, and Black. One plugs into a Fan header and the other plugs into a Flow header so I guess the signals are different. Apparently this was not the case with the High Flow sensor because based on the cables listed (#53027, #53212) it only had one 3-pin output header. I am curious what the difference is between the Green wire and the Red wire in this breakout cable because the original High Flow sensor sent the same exact signals to a Fan Header and a Flow header but the HF-2 and HF-LT have a separate 3rd conductor for these 2 connectors.

This makes perfect sense except I do not understand why the Red wire is necessary in this case. There is no PWM fan. The old High Flow had a 3-pin header based on the 2 cables listed for it. The only difference in these cables is the connector on the other end. One is a regular 3-pin fan connector and the other is a pico-blade connector. They both get the same 3 conductors which I assume are GND, Speed Signal, and +5VDC. Why doesn't this cable just loop the green wire from connector to connector like the black and white wires? Why does the cable for a D5 Next need to have a different wire (the Red wire) for the HF-2 and HF-LT, but not for the old High Flow, which used the same 3 wires for both?

Yes I suppose it is due to some difference in the flow sensors. If the old sensor required 12VDC, the pico-blade connector does not provide this. Its a mystery I guess. It's all really academic and just my curiosity.

Thanks for sharing your insights about this.