The aquastream ULTIMATE pumps can be connected via aquabus. You can use the supplied 3-pin cable that comes with the pumps. Since you have a real time clock module that features an integrated aquabus y-splitter, you can connect the pumps there.
The pumps use the same aquabus ID number by default. You have to change it for one of the pumps. This can be only done via USB with the aquasuite software in the system tab of the pump.
It is recommend that you connect both pumps via USB or at least make it possible that you can access their USB ports. If a firmware update becomes available, it can be only updated via USB. This might be a necessary step to stay compatible with the aquaero.
If a USB hub is required depends on the available USB ports of your mainboard. If there are ot enough ports available, then you need a hub or as suggested you only connect the pumps if necessary.
Splitty9 comes with a 4-pin connection cable. This allow the usage of voltage or PWM controlled fans. A 3-pin cable would only allow voltage controlled fans.
You did not mention the exact type of flow sensor. If we are talking about the classic 3-pin sensors like the High Flow sensor (without USB/aquabus), then you need this cable to connect it to the aquaero:
https://shop.aquacomputer.de/product_inf…622&language=en
If it is a USB/aquabus enabled version, then you need a y-cable for the aquabus in addition:
https://shop.aquacomputer.de/product_inf…847&language=en
You could use the supplied 3-pin cable for the aquabus but this will only work if USB is connected too because otherwise the sensor will get no power. A 4-pin aquabus cable would solve this problem and allows you to remove the USB cable. Again you should be aware that a firmware update is only possible via USB.
https://shop.aquacomputer.de/product_inf…846&language=en