Water cooling is cool, literally. The jacket for my wcv6 from @Rene_Jurack came today.
Black matte beauty 
Hey Rene, can I get a cheap water block like this and put a peltier on it to chill the water? https://www.aliexpress.com/item/Primary-Aluminum-Water-Cooling-Block-40-40mm-for-Liquid-Water-Cooler-Heat-Sink-System-Silver-Use/32805476707.html
slow mauritian internet doesnt let me check your link but if it is some generic cooling block: you can. But then you have to regulate and cool it, too. Otherwise you can freeze your water - and you dont want that!
- it is REALLY uneconomical
Interesting, I will add a thermistor + run the peltier from a mosfet and set the temp to 10C 
Dunno if a peltier will suck enough watts to work very well. Heatsink cooling should only be a few watts, which might be fine, but the watercooling pump can put a lot of heat into the loop too. If the watercooling loop has to shed more heat than the peltier can pull at rated power and temp delta, it’s worse than nothing.
You should try it and let us know how it goes
I am willing to spend $5 and be the data point.
the peltier will also produce heat - what advantage did you hope for? did you want that below 30°C. You also need a heatsink for the peltier as you need to purge the water heat AND the heat of the peltier. A big water Tank would also work fine without the need for additional energy - you probably need a 100W peltier.
There are peltier temp controllers, on eBay cheap. I bought some but haven’t used it yet. Use liquid with antifreeze.
I could use just antifreeze, since I already have that.
@Christian_Meiser Make the sealings wet before re-fitting the jacket. Otherwise you are going to damage the sealings.
@raykholo It will work, I already did it. Please mix the car coolant with water. Coolant alone hasn’t a good heat transfer rate.
I got mine yesterday too! Now just waiting for the rest of the parts I need
Add a little graphene ink to the water coolant for better heat transfer.
@Herman_Steyn You mean snake oil? Graphene only improves heat transfer performance under very specific and tightly controlled conditions, and will make performance worse if you use too much. Minor tweaks to the watercooling loop hardware (eg bigger pump or radiator) make ten times more difference. Graphene is a waste of money for this kind of application.
Useful background reading http://www.mdpi.com/1996-1944/9/6/455/pdf
Guys, please… We are in need to cool down a 3-5Ws heat source with equipment for CPU-cooling that is made to cool 50-100W. I did like 15 different setups and ALL just worked. I can cool 3 hotends and 6 TMC2100 drivers with just ONE 80mm radiator+fan on 50% voltage. No need for overkill…
Yep, I don’t think the E3Dv6 even needs 3w of cooling. It’s very, very tiny heat dissipation for a watercooling rig. We have overkill in nearly every design area here.