Water cooled spindle water

Just wondering what you water cooled spindle folks use for water. I noticed my water gets algae pretty quick, so I added a bit of bleach, which helps a lot. I’m just wondering if bleach is safe for the spindle. Could I just use a pool algaecide? I know some of you are using antifreeze. Is there a specific reason for that? My setup is inside so there’s no risk of freezing.


I use this stuff, which came with my spindle. It’s water with monoethylene glycol (antifreeze), “OAT” corrosion inhibitor and who knows what else.

I have been using car antifreeze and no algae in sight after 2 years.

1 Like

Julien may be on to something. Auto antifreeze has anti corrosion additives and can stand high temperatures. I dont think a spindle gets near as hot as a car but the Ethel glycol dissipates heat well. I remember Julien has a chiller as well.

The spindle manufacturers recommend ‘super grade’ glycol coolant. The nearest I could find was top drawer automotive, such as Fuchs. Mine’s been algae free for 4 months so far

Bleach is probably not a good idea from a corrosion perspective.

An anti-corrosive such as anti-freeze is a good idea, ethylene glycol has a specific heat capacity only a little lower than water so it’s a good choice (which is why we use it in vehicles…)

As for algae, I suspect the main factor will be whether you have a closed circuit such as with one of the packaged chillers or an open circuit which allows air, dust and other things into the spindle water in which case it may go a bit smelly over a few warm months.

1 Like

I’ve been reading up on this topic a lot lately and have seen many references to using an anti-microbial for PC water cooling systems as an additive to automotive antifreeze based coolant (~20% solution with distilled water). As you might expect there is some difference of opinion on the internet about the need for additional additives beyond the automotive antifreeze. Open loop systems would be at higher risk for algae or other things growing. Just make sure what ever additives you use they are rated as being safe for the mix of metals and plastics in the system. If you add a chiller the radiator could be copper or aluminum.

1 Like

Pre Mix PC water cooling liquid is around 20 dollars a liter. Is good for a year. Try to get a copper rad.

Are you just running an open bucket water supply?

Up to this point it’s been a bucket with a loose lid. I just got a 3000 chiller so I want to put the right stuff in it before I power it up.

1 Like

I’ve had one running with a CO2 laser at my school for years. Distilled water from the grocery store. Replaced maybe once in 5 years. Nothing growing in there. And had to refill when the aluminum coils sprung all the leaks (keep some jb weld on hand)

1 Like

I would not recommend using only distilled water without corrosion and biological inhibitor additives, otherwise distilled water will strip electrons from the metals causing oxidation and eventually microorganism growth in the coolant, mixture of metals (i.e fittings, radiator, spindle itself) also causes this. If the spindle is in an environment that can go below freezing, automotive antifreeze otherwise PC water cooling additives should be added to the water.

1 Like

@DanStory Got a recommendation for a PC water cooling additive? I have zero experience with that stuff.

EK-CryoFuel Clear Concentrate 100 mL EK-CRYOFUEL-100-CL (performance-pcs.com)



With a large reservoir you might consider auto antifreeze. I bought the blue Zerex Asian formula for my chiller.

I used EKWB EK-CryoFuel when I first installed my spindle (as @CNCInspiration recommended) in the summer months but switched over to automotive antifreeze due to Colorado winters and my unheated garage :frowning:

I went the extra mile and also used no-spill quick disconnects. Makes my life easier on maintenance/disassembly.


I use Prestone 50/50 with a CW-3000 chiller.

This topic was automatically closed after 30 days. New replies are no longer allowed.