This one simple hack could save you money
|Coolflow DTX from Hydratech, good for lasers|
If you have the CW3000 you're going to need 2.25L of antifreeze and if you have the CW5200 you're only going to need 1.5L. The internal reservoir of the CW5000 series is smaller because it actively chills the coolant. Small quantities can be purchased via ebay and the usual sources at sensible prices (or from laser importers at inflated prices), 5L bottles can be bought directly from Hydratech.
On the back of the chiller is a drain outlet (the bottom left corner), simply unscrew this cap and drain the approximate amount of liquid into a measuring jug. Dispose of the water in the usual way. Then simply pour the antifreeze back into the top of the chiller. Once the chiller is turned back on you should see the coolant start to circulate through the laser tube.
Thanks to Graham from DeathZap Studio for prompting this post after our conversation on the subject