Had an old Gigabyte GTX1070 that worked but had a circuit fault in that it wouldn't run fans. (Tested fans and wiring, definitely circuit fault). I could have jury rigged some fans to run off the motherboard but never got around to it.
When I stumbled across this
ID-COOLING IceFlow 240 AIO VGA Liquid Cooler, I thought I would give it a shot and I'm pleased to report it works very well indeed. It is whisper quiet compared to the standard fans and maintains an even temperature roughly 16 degrees (celsius), less than the aircooled standard. It's designed to fit a wide range of different GPUs, (includes a lot of different brackets).
Uses around 10 watts in total but the biggest negative is the size. I have 8 GPUs in my rigs and now I have one radiator hanging off it, I can't imagine trying to fit 8 of them. Pity though, as the absence of noise is blissful. Anyway, thought I would post this in case anyone else is curious about watercooling their GPU.