Pirelly's "Why you SHOULD NOT use JUST distilled H2O"

[jb2cool]

Hello there!
In this thread there are some tips for all you guys just starting out with watercooling. This was made with the help of WS_JP, Cathar and many other WaterCooling ?Xperts?. After reading through it, you'll probably have a good idea about what liquid to use in your watercooling setup. Some of the more experienced users are probably already aware of Corrosion and algae growth, so this thread is probably of more use to people just beginning with watercooling.

First thing to say is that with using the wrong cooling fluid solution, you CAN damage your complete watercooling setup.
Here are a few examples of what can happen:





Now that I got your attention, here goes.

What actually is distilled water?
Distilled water is water which has been heated to the boiling point so that impurities are separated from the water, which becomes vapor or steam at 212 degrees farenheit (100C). Steam is then cooled and condensed back into pure liquid form. The impurities remain as residue in the steam kettle. Distillation removes waterborne biological contaminants such as bacteria, parasites and viruses, organic and inorganic chemicals, heavy metals, volatile gasses, cysts, and other contaminants. Pure water contains no solids, minerals, or trace elements. It is clean, natural, and (supposedly) healthy (I still wouldn?t drink it though) .
You can get this stuff in most car part shops or even the supermarket/pharmacy.

Distilled water is not the same as Deionized water!!!
Water is de-ionised by passing it through glass columns containing deionising resins, and the output will contain no metal salts, acids or alkalis or other substances which ionize when dissolved in water. But it may - and probably will - contain substances which do not ionize.

Both can be used for around the same purposes tho. I'm not sure if one of the two can be preferred in a watercooling setup. Read more about this here.

So, this all looks great. But why can distilled water harm a watercooling system if it does all those great things???

I found the reason over here:

The problem is called Galvanic Corrosion.
Galvanic corrosion can occur when you use a system with a copper waterblock and an aluminum part (or other metal less pure) inline:
The copper corrodes a little, as copper in water or air always will. This is normally not a big deal, because a thin copper oxide layer forms and protects the rest of the metal. But in the process, some copper ions go into the water solution and make their way around (thanks to the pump) to the aluminum water block. They precipitate onto the water block surface as teeny little metallic copper particles.

Now you can get plain old galvanic corrosion; the copper and aluminium are in physical (and thus electrical) contact, and both immersed in the electrolyte. The mess you end up with is mainly aluminium oxide, with its greenish colour donated by a light lacing of copper oxide.
(This process also happens in some car batteries which you can also fill with distilled water).

Here's more pictures of some messed up blocks:





Now, you probably noticed there are two sorts of corrosion in the pictures above. The one I talked about (Galvanic Corrosion). The other is more a bacteria/algae problem.
This should (in principle) not happen with distilled water. It could happen however if you take normal tap water, where there are still bacteria and chemicals inside (read more about this at the end).

In order not to have your block looking like that after a few weeks/months, the best thing to do is to add a corrosion preventer to your water solution.

I also just (26-02-2005) got in some great tips from MARZZ (who has had automotive mechanical training).
Here's what he had to say:
One of "the big three" car manufacturers on a few cars has had a galvanic corrosion problem, and the TSB solution was to ground the heater core better, this eleminated all of the electrolysis effect that caused galvanic corrosion in the heater core. So one could attach a wire from a metal cooling block to the main case or the PSU case, and effectively remove any electrolytic activity in the metal parts.

I've not verified it myself, but it seems a logical thing to do. I assume in order for it to work, you'd have to ground every component in your cooling system (blocks and radiator).

So, if you choose to use a fluid, which corrosion preventers can you use?

These solutions come in various forms and qualities.

Most people probably know WaterWetter



You can add this stuff to normal water and distilled water. The recommended ratio between anti corrosion solution and water is 5% to 95%.
WaterWetter does a very good anti corrosion job, but it also has it?s disadvantages. One thing is that it stains silicon hoses.

Here's an example of a stained hose (after one year use in a cooling setup). This has happened with my UV cooling liquid, but waterwetter does the same, only it's purple/pink colored:



Cathar had the following experience with WaterWetter:
Water Wetter can be immediately bad if used in high concentrations (>10%). The recommended concentration is 5% however if you change your water regularly, then even this concentration can be too high.

Water Wetter does its job by leaving a thin film coating over the surfaces, and this is what reduces the effect of galvanic corrosion.

Over time, through multiple changes, this coating continues to build until eventually it sloughs off in clumps and can potentially clog up systems.

If you look at the discolored hose, this backups Cathar? point. That?s why I recommend using the right ratio of WaterWetter (or even a bit less). I?ve been using my watercooling system with WaterWetter for over 1,5 years without changing the water (I just added some new if the reservoir was getting empty). I now got it build out of my system and there is NO residue or discoloring on any of my blocks/radiator (only the tubing).

What more can we use apart from WaterWetter?
As I said, there are a lot of variations.
Innovatek sells their Innovaprotect

At the moment im using ?Klax corrosion protect UV sensitive?.
This has been in my system for over 1 year and there's still no sign of corrosion.
It is a corrosion inhibitor and glows when you have an UV CC.

There are also a lot of UV adittives available. Most of these do not prevent corrosion (they can stain the hoses, like in the picture above), so with that you still need a corosion inhibiter.

There are more and more solutions for sale. Just check out your local watercooling store.

Now that I talked about these solutions; I also did a small test to show you the capability the fluids have.
Here?s the setup:



You can see the types of metal I used in each glass and the type of fluids. Notice the first is only distilled water.

Now this is how it looked after only FOUR DAYS



So only distilled water will give you very fast corrosion (off course it was steel which corroded first, but it?s only to show you that the other mixtures do a good job in preventing it from happening). It did look like the uv stuff started to corrode a little eventually. So I?m still into this?.. (it?s only the steel tho, and we arent using that in our setups).

Here are some other tips:
From Cathar: When using an all copper/brass system, then using straight tap water is generally fine, unless the brass is of particularly low quality. You may see some blackish discoloration of the brass after a few months, but this actually serves to prevent further damage. The brass will pretty much stay intact for a very long time.

Want proof? Look under your sinks in your house (or maybe a friends house). Many houses use brass/copper mix for pipes and fittings for decades without any form of corrosion protection and they don't suddenly corrode away.

In general, if you use an all copper/brass system, you don't need anything more than plain tap water, but to prevent fungal growth, a few teaspoonfuls of laundry bleach is usually sufficient.

Now Aluminium is bad news. So is iron/steel/zinc which is what screws are made out of. You'll notice in the opening picture that the screw is what is badly corroded, because zinc/iron is less noble than copper (the major component in brass).

Mixing metals of disparate nobility is bad. In this case, you can use Water Wetter, but as noted, it can cause problems over an extended period of time/water changes, and it doesn't stop fungal growth.

You can instead use a small dose of radiator corrosion inhibitor, which suspends a sacrificial metal of lower nobility than aluminium in the mix, and it is this metal that gets eaten away first. Don't worry, you can't see the metal, it's ionised into the inhibitor liquid. Over time (every 6 months to a year) you'll need to change the liquid because it loses its effect.

The glycol in the corrosion inhibitor is also a very good anti-fungal/anti-bacterial agent. Basically it'll do the job of Water Wetter + bleach, all at once. Even better, it doesn't leave deposits/films all over the insides of your system that can clog up stuff over time, and potentially reduce the thermal convection efficiency of your cooling pieces.

People will then complain about that anti-freeze has lower thermal capacity than water. This is true. Anti-freeze has about 1500J/kgC of capacity, while water has about 4200J/kgC.

However just a 5% concentration of corrosion inhibitor is enough to last you 6 months and provide all the bug killing aspects that you want.

At a 5% mix, you have dropped the thermal capacity of the total liquid by 3%. What does this mean? In the grand sum of things, it means maybe 0.01C higher temperatures. Whoopdiedoo! The CPU's gonna melt-down now!

Water Wetter however, with is filmy deposits, reduces the thermal convection efficiency of everything over time, possibly leading to worse than 0.01C warmer.

Water Wetter is a nice short-term solution, but longer term, it's pretty much something you want to stay away from. If you use mixed metals, use a true-blue radiator corrosion inhibitor, or if you don't used mixed metals then just plain tap water and some bleach does the trick just nicely.

Another tip I got from MARZZ is this:
In oder to eliminate/control algae growth you can use the solution that waterbed shops sell for the care of the vinyl matresses. This offers great protection (without harsh chemicals), as bleach can and will attack some metals, and vinyl hoses.

Antifreeze used in cars is also a good solution. Don?t use to much (I?d stick to the standard ratio).
I did the same test with antifreeze and it looked like this:



And after four and even more days, it?s still looking the same.

So, why not use plain tap water?
I think there's nothing wrong with that, but.........there are many minerals, chemicals, metals and other stuff in tap water. Now at the temperatures this is getting in our average cooling systems (a bit warm), you get a very good environment for bacteria and algae growth!!! (remember the first picture?? )
So if you want to use tap water, I also suggest you add some corrosion inhibitor (and/or check your blocks regurlarly)

So, I guess that?s about it???.
I hope I made the decision of choosing the type of corrosion preventer a little easier.
If you have any comments or suggestions, please let us know!!
Keep the thread tidy..........

Remember: The things said here are only tips.
It's not THE way for use in watercooled systems. Each system has it's own characteristics and could react different to certain fluids.

And stay away from the distilled water WITHOUT any corrosion inhibitor.

Oh, BTW if you have anything you think should be added...... Please post a reply to me or PM me. Than I can include it with reference to you!!

Thanx to WS_JP, Cathar and all you other guys/experts for your imput...........
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[E_PaiN]

I had it saved too
Sticky please!

[jb2cool]

had to save these. I have found them so usefull in the past. Didn't have it saved though so a fit of furious copy/paste
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[Rainking]

I had it saved too
Sticky please!

Seconded ! Sticky please !

[Phantom66uk]

*Stuck* Still an excellent guide [yes]

[xxORBxx]

Nice work once again.

[Drunkin]

I don't have any experience in water cooled computers but I do have experience in steam turbines and power plant chemistry. This all seems a lot similar and trying to achieve the same goal. Minimize corrosion and organic fouling.

If I was to get into this I would treat it like a power plant because that's what I know. As with a power plant we start out with De-ionized water and add the chemicals we want back into the water to maintain a givin pH, Total disolved solids and other chemical characteristics. Copper/nickel based alloys are used in most heat exchangers due to there corrosion resistance, thermal properties and strength. The chemistry is maintained to build a "good" layer of corrosion and prevent scale which is bad at transferring heat.

I'm sure the same could go for this application. The only differance is the possibilities of oxygen and the absence of continously boiling the water and releasing air and non-condensable gases.

I'd like to elaborate that it is extreamly unwise to use tap water. Tap water is good to drink because it contains minerals that the body needs to function but is very poor when you are trying to create a scale free, heat transferring efficiency cooling medium. Unless of course it is distilled further or run through a reverse osmosis unit. Keeping things such as algeas and other organic life dead in a system like that can cause a problem if not kept in check. We use chlorine in cooling towers, something you probably don't want in your cooling system. Chlorine has a very high oxidation potential, and can actually attack your water blocks, just as chlorides do in a steam generator. Really good at killing off life however.

Questions about waterwetter and anti-freeze:

Should water wetter be used as an initial treatment to establish a "good" layer of protection?

Then switch to anti-freeze to keep all the organics dead?

[ChristianIreson]

Well, I used DI water and some anti-organic tablets for aquariums, and it ate the copper out of my waterblock and put a layer of copper throughout my piping and heat exchanger....so if I ever do try water-cooling again, Ill use a much different anti-organic chemistry.

[jb2cool]

just reviewing this thread and i see that a lot of the images are now dead. If anyone has any decent images that they'd like me to substitute into the thread then feel free to contact me.

[Pirelly]

Darn, the pics are gone...
My site (www.pirelly.nl) was taken offline a long time ago.
Lets see if I can still find a few of them!