Hello friends, I come with another question, in one of the machines I observed a turbulent flow and bubbles, in a previous post I read that bubbles and a turbulent flow affect the useful life of the tubes, my question is what damage a tube can suffer by not solving this. In my case I only added coolant until the amount of bubbles was minimal.
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Bubbles isn’t a tube killer, when they stick and prevent the coolant to touch the inner tube, they really become a problem.
I ran distilled water, then move somewhere it can freeze, so added some propylene glycol, used to treat ketosis in milk cows, to the coolant. That created millions of tiny bubbles.
I was concerned, so I wrote a note to Russ Sadler and asked him, along with this video.
He advised that if they don’t stick, then you’re ok.
Good luck.
I have bad experiences with air bubbles in cooling systems, if the bubbles hang the wrong place they can overheat and it can lead to a kind of micro pitting that attacks the surface.
I allow no air bubbles in my system, it takes no time on my little machine getting rid of the bubbles, so that’s what I do, always.
to avoid bubbles (cavitation) try to put your tank higher than the laser tube, but not too high so that your pump has enough power to raise the liquid, at the outlet of the laser tube, put a connection T, with a piece of vertical tube of at least 30cm, at the end put a stop valve, this works a bit like on a car or an aquarium, will allow you to purge the air, if possible when filling, try to tilt the laser to chase the bubbles towards the outlet.
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Turbulent flow is often a good thing. Laminar flow has an almost stationary layer of liquid next to the glass. Turbulent flow on the other hand has better contact with the surface. Rotating the tube and /or tilting the laser should get rid of the bubbles (add a couple drops of dish soap to decrease surface tension and assist in getting rid of the bubbles. If there are no holes or leaks on the intake side of the coolant pump, then once the bubbles are gone, you should be good to go.
Of course I’m not saying to turn off the pump! But just to chase away all the air bubbles, as you do in an aquarium or in a car. A simple tube with a tap that goes up higher than the entire system (mandatory otherwise the siphon effect will empty the system!) allows you to effectively remove air bubbles. Also consider checking for leaks with toilet paper (free and effective), but also what no one thinks of, rubber pipes! Invest in silicone tubes, terribly effective and cheap!
When I used the glycol, it is what caused the bubbles after going through the pump. You can’t stop them from forming.
So there is a difference as to what a bubble is.
If it is because of glycol, try to find a product that reduces or stops surface tension.
Hello friends, I update you, my machines use a chiller to which I put 5.5 gallons of demineralized water with 1 gallon of automotive coolant, I can say that it is almost an ideally laminar flow since the bubbles are extremely minimal.
… Do you live in Alaska ??? 
No, but my machines use 4 170 W tubes and the chiller holds almost 7 gallons of fluid.
I am writing to you from the south of the continent
Well, better said in the middle of the continent
I don’t know how cold it will be where you live, but 1L Antifreeze sounds a lot 