I think we need a different cooling solution. Ambient temperature here in Hong Kong is already around 25℃ with aircon, and there is stuff growing in our tank:
Plus, the thermometer setup stopped working:
So I’m thinking about replacing it all with a compressor based solution:
What specs should we look out for? Any suggestions?
Of course I am aware of choosing a proper coolant, which apparently hasn’t been done before (stuff growing in our tank): Watercooling, different coolants - K40laser.se
My Fabcreator 40W cutter came with a S&A industrial chiller cw-5000
Thanks, I can find these on Taobao, but according to the article CW3000 cooler for lasers – Warning! article on k40laser.se, some of them may be knock-offs (could perhaps still be sufficient). I would like to find out more about the original manufacturer. Does S&A have a web-site?
Just so you know, @HP_Persson who was active in the Google+ community preserved here, and who runs k40laser.se, has gained a reputation on this site relatively recently for accepting people’s money and not shipping the product. I’d be happy to hear that this was isolated and ultimately corrected.
There are many posts on this site specifically recommending Tetra Algae Control, including our introductory article:
(I’m not a source of information on knock-off chillers; I’ll leave that to others.)
Thanks for the link to the article! Concerning Tetra Algae Control: In our case, mold seems to be the bigger problem. On the bottom of the tank, there is red slime. Growing from the pump is white slime. The inside of the tubes is covered with black deposit.
I read that some use a small amount of bleach in the water. Originally I was thinking that this is a bad idea as it is corrosive and it can damage the rubber seals and tubes. However, after seeing the mold problem that we have, I’m reconsidering. In the end we probably have to replace everything.
Oh, I think there are varying recommendations on bleach.
I think one of the issues is that some laundry bleach has extra additives; for example, we have some “low-splash” bleach that has something in it to increase the viscosity, and who knows what that does to conductivity?
The other is that even pure sodium hypochlorite does increase conductivity somewhat, so it’s a tradeoff between two problems for you:
Maybe it’s best to simply replace the distilled water once per month.
That’s the safest and cleanest 
One of the members of our hacker space builds a custom water cooling system for a PC. The other day he mentioned that he tried running the PC just with distilled water. Within days, he had algae in the system. So he recommended using a biocide, though I think he couldn’t recommend a particular one.
Indeed it now has happened: Within weeks, maybe even days, we had stuff growing in the water cooling system for our laser. So I went to the chemist and bought some bleach:
This should have no additives. In the article LaserGods article Laser Water Coolants & Additives it says: “Testing has shown that 6 ml of Clorox with 5 gallons of water gets a conductivity reading in the neighborhood of 40µS/cm and this is a sufficient amount to inhibit the growth of bacteria and algae.”
I know there is varying, even opposing information on the web, but yesterday I decided to go for bleach. That is, after replacing all the tubing again, including the pump, which is now much stronger at 45W. I did this also to move the water tank to a more accessible place, which requires longer tubing.
For measuring the conductivity I got a conductivity meter:
Aquarium algaecide work just fine…
Also against mold? (big problem here)
We looked around and found that Tetra Algae Control is not available in Hong Kong or on Taobao.
Thanks for the link!
