2 Weeks running, "silver" kill coil covered in hazy algae? - Page 6

A crucial difference between the cowboy's drinking water and the water you use in water cooling system is purity. Silver does not dissolve in water. The distilled water you use will certainly not be clean for very long, among other things, it will take up CO2 as soon as it comes in contact with air and become slightly acidic. Something silver will be dissolved as ions, but in very low concentrations and very probably not enough to have any effect at all.

Is there evidence that silver prevents organic fouling in the water cooling system? No, absolutely nothing. In forums around you will find users who claim to have good experiences with silver and you will find users who claim that the silver does not have any effect, it grows anyway.

A prerequisite for organic fouling is the presence of microorganisms. Using new and unused components and only distilled water can get a water cooling system free from organic fouling. Feel free to choose to use silver as well, but the absence of fouling should be attributed to the absence of micro-organisms and the presence of silver.

What about the galvanic corrosion, silver would be a danger in this respect? Proponents of silver would argue that there is no risk and refer to the galvanic index. It is a mistake. The galvanic index applies to metals that are in contact with each other and are not relevant. For two metals immersed in electrolyte (coolant) must be risk assessed based on Standard Electrode Potential. On the table is unfortunately silver is a good distance away from other metals such as aluminum, chromium, nickel and copper.

In other words, your silver have not taken up enough Co2, which causes it to dissolve and kill algae. On other hand, the dissolved ions will cause corrosion.

Edit : I dont have much experience with water cooling, so i wouldnt know if it was the silver coil is causing your problems. Though, i know a fair amount of chemistry and clean environments.
Edited by Inconvenient - 2/15/12 at 2:59am

Blue fluid is often a copper based compound. Strip out the loop, wash it through with vinegar again, and dilute that vinegar with distilled water. Then give the loop a few more rinses with distilled before putting it back together.
My chief suspect for the trouble is excess solder and loose copper fragments from the manufacturing process. That would be enough to pollute the water, and limit the effectiveness of the silver (assuming you didn't get ripped off).

definitely not biological and definitely not algae.

What you are seeing is some type of corrosion from impurities in silver, ie oxidation/tarnish, etc.

Also this is not the first thread of discoloration of silver in loops.

Xtreme had thread with several people with same thing, some even had complete brown/black deposit all over it. Silver kill coils are 99.999% silver, at least some are. 99.9% pure silver (which is all you get at local jewelry stores) though has enough impurities to get surface discoloration just from water, let alone tin/brass from rad, one of makers of one of brands kills coils had chimed in about it as well in xtreme thread. Couldnt find the other thread with quick search, dont have time, but several people had the same surface discoloration of silver, and most that had the issue were not using silver kill coils but less "pure" silver from jewelry stores etc.

But someone should be able to find the other thread(s).

Couple quotes from silver store and wiki:

"The mixture of silver with copper or other metals is actually the cause of the tarnish that you might find on your silver pieces. Silver is very unreactive as a metal.."

"Commercial-grade fine silver is at least 99.9% pure, and purities greater than 99.999% are available."
Edited by opt33 - 2/15/12 at 5:13am

Silver can come in any shape. Just because most kill coils are flat strips does not mean silver wire is automatically inferior. Seriously, doubting that it's silver because of it's shape is dumber than thinking the difference between electrical and duct tape is one of color.

I don't see any algae; I see some minor tarnish.

What would cause silver to tarnish other than exposure to sulfur? Are corrosion and tarnish words for the same process or are they unique?

Tarnish only affects the very top surface layer. Corrosion can disintegrate the metal.

Oxidation FTW!

It's still solder...... *yank yank*

Assuming that it is indeed soilder its likely that its not 100% pure and has at least a small amount of lead in it. If that's true then what your seeing is most likely galvanic corrosion from the copper in your rad to the lead in the solder. This is because lead has a relatively higher electronegativity than copper (2.33 and 1.90 respectively). Conversely silver has a very close electronegativity to copper (1.93) so it does not usually cause galvanic corrosion.

There is a great deal of evidence, and silver has been used as an effective preservative and microbicide for thousands of years.

The fact that some people with silver in their loops still get growth says nothing about the effectiveness of silver, just the effectiveness of the user. Any controlled experiment of algae growth will show that the presence of silver reduces such growth over a control sample.

Hydrogen sulfide is technically needed for for silver to tarnish. I was using it in a more general/imprecise manner. I probably should have said corrosion.

Tarnish is a type of corrosion, but not all silver corrosion is tarnish.

It's not solder, it's silver wire.

Also, most silver solder is just silver bearing solder that is mostly not silver. Real silver solder is high temperature stuff used for making jewelry, and not for soldering electronics.
Edited by Blameless - 2/15/12 at 8:04am

Ah well the point I was trying to make is that it most likely isn't algae because you would see that in other parts of your loop. The silver wire most likely contains some other metal that is causing corrosion from the copper onto the coil.