it will work fine. you'll only have to play with software sensors to use like the temp sensors of your current one to drive fans or pump on the other.

Yes you can connect another Quadro to a motherboard USB port (while powered down, of course). After you connect it, when you boot into Windows and Aquasuite opens, you will see both Quadros in the left side panel. They will operate independently - no conflicts. There are some advantages to having 2 x Quadros versus 1 x Octo. You will have 8 x temp sensor headers instead of 4, and 2 x flow sensor headers instead of 1. You will also be spreading the fan load across 2 x Molex power connectors instead of 1.

You could avoid adding the second Quadro if you group more fans together with a Splitty or some other PWM splitter. Grouped fans will all get the same PWM signal, so they will run at the same speed (if they are the same model fans). Whether this is a problem depends on how granular you want your fan speed control to be.

You didn’t specify what pump you have. If it’s a D5 Next, you can control the speed in Aquasuite. If it has a PWM cable for speed control, you could connect it to a mobo PWM port instead of the Quadro and leave it at a fixed speed. Varying pump speed does not really do much, and it's harder on the pump. To find the minimum speed, connect the pump PWM cable to a Quadro PWM port, set it for 100%, then start reducing the speed while monitoring temps. You will find that at some point, temps will start to increase, probably when the speed gets down to 25 to 35%. Once you find this point, increase it a bit and leave it. Then, move the pump PWM cable to a mobo PWM header, and set it for the same speed in the BIOS. Your pump will now operate just above the minimum speed necessary to sustain optimal temperatures while minimizing power consumption, noise, and waste heat, and it's not using up a Quadro PWM port.

the aquacomputer flow sensors go on a dedicated header on the Quadro, so it won't take a PWM header

Quoted from "n3rz001"

Yeah i m not planning to buy the aquacomputer one , it is ugly, i will take another brand.

Which flow sensor are you planning to get? The Quadro and Octo do have a Flow Sensor header, but AFAIK, they can display the flow rate, but that is all they can do. I think control sources for fans in the Target Temp and Curve Controller modes can only be temperatures. I guess in the Playground you could make a virtual sensor with the flow rate as the input, scale it, and make the output unit be °C. Then you could control the fan speed with the flow rate, but I don't think it makes any sense to do this.

Quoted from "n3rz001"

Yeah i m not planning to buy the aquacomputer one , it is ugly, i will take another brand.

Wow if you only want a flow meter to look nice then.... but if you want one to accurately measure flow then the HFN2 is the way to go. check this this if you want an accurate flow reading

Quoted from "Bartdude"

but if you want one to accurately measure flow then the HFN2 is the way to go. check this this if you want an accurate flow reading

I read that Igor's Lab article years ago and was amazed at how bad the Thermaltake and Barrowch flow meters are. It was written 5 years ago. Since then, Thermaltake released the TF2 and Barrowch has released the FBFT07 and FBFT08. I wonder if any of these new models are more accurate than the models Igor's Lab tested. Koolance also makes a BUNCH of them and released the DCB-FMTP01 display unit in 2024. I suspect the Koolance products are accurate, but since I use Aquasuite to monitor and control my cooling loop components, I see no reason to use anything other than an Aquacomputer flow sensor.

Personally watercooling is for the performance benefit and keeping my components cooler than they were on air. Just having my GFX card run at 50c max under load rather than 70/80c or more on air is a massive difference, the aesthetic side I see as a bonus and is secondary to everything else.
Problem is most manufactures look at the aesthetics first and performance comes second, more interested in adding fancy RGB etc. Not that you can buy many components that aren't adorned with it now but that's where we are.

Just a quick note if the idea is to somehow connect a different flow sensor to the flow port: QUADRO only supports the impulse rate conversions of our sensors. It is not possible to use a custom value.