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Cleaning your loop after bacterial/ algae 'infection' (With pictures) - Page 3

post #21 of 25
Own a Thermaltake Bigwater 760 Plus.
Green tubes, Stock.

Coolant Specs
Ultra-value: UV Sensitive
Major:
- Material Water~94%
- Propylene Glycol ~6%
Other materials:
- Ethylene diamine tetra acetate detetrasodium (ED .TA.4Na)0.1%
- Methy paraben (M.P) 0.1%
- Color pigment 0.002%

Just curious as to what i should add to this loop too keep algae at bay... it seems a lot of people on this thread know a lot.
post #22 of 25
Thanks, might have to do this when I get home...
post #23 of 25
The other day I noticed what appears to be potential crud buildup in my Swiftech AIO reservoir:



Does that look like algae growth to you guys?
post #24 of 25
Quote:
Originally Posted by BababooeyHTJ View Post

I'm bumping this thread since I had also though that ethylene glycol would act as a biocide. I was wrong.
It does if you have >20% concentration and an alkaline pH.

An expert said biological growth is rarely an issue if the glycol is kept at a high enough concentration. He also said that if it goes below 20% it will be attacked and degraded by microorganisms.

The problem with silver for the kill coil is that it's a .50 galvanic difference from nickle.

Of course, ethylene glycol is toxic as well, and does evaporate (although slowly)
Edited by superstition222 - 10/7/16 at 2:14pm
post #25 of 25
Quote:
Originally Posted by Markes12344 View Post

Own a Thermaltake Bigwater 760 Plus.
Green tubes, Stock.

Coolant Specs
Ultra-value: UV Sensitive
Major:
- Material Water~94%
- Propylene Glycol ~6%
Other materials:
- Ethylene diamine tetra acetate detetrasodium (ED .TA.4Na)0.1%
- Methy paraben (M.P) 0.1%
- Color pigment 0.002%

Just curious as to what i should add to this loop too keep algae at bay... it seems a lot of people on this thread know a lot.
That coolant doesn't seem very good, from what my research has shown. The standard in anti-corrosion for copper is an azole rather than EDTA. Also, one expert said glycol needs to be >20% to prevent it from being broken down by microorganisms. I would avoid pigments also since everyone and their mother claims they clog micro channels. EDTA apparently does keep its trapped ions in solution, though, rather than precipitating them, which is good. Maybe in a high enough concentration it could work but I would assume it would get used up pretty quickly. Maybe I'm wrong.

As far as biocide, I assume that if you have enough galvanic corrosion inhibitor then a kill coil might be OK but enough inhibitor might prevent it from leaching the ions that kill microorganisms. I'm not sure what the best alternative to toxic ethylene glycol is for growth inhibition. However, an alkaline pH and >20% propylene glycol may offer enough biological protection. That expert said "glycol loops" and did mention ethylene and propylene loops. Azole anti-corrosion inhibitors are toxic so they might do the trick.

There are also borates (tetrasodium borate, "Borax") which people use in pools to prevent algae growth. I know they're used in some commercial water loop system and vehicle coolant formulations but I don't know how well they'll work in a computer loop, particularly in a high enough concentration to prevent growth. It would be essential that they not be allowed to precipitate because the crystals are abrasive and would reduce pump life. Fortunately, they are pretty much non-reactive. So, if you can get them dissolved at the lowest ambient that your loop will be exposed to that should help. However, as the water becomes contaminated with other stuff it might force the borate out. Borate raises pH, although not as much as potassium hydroxide. So, it's often used as a buffer given its non-reactivity.

IBM appears to have used just an azole (benzotriazole) with distilled water for a computer watercooling setup. The pH of the water needs to be elevated to get benzotriazole to dissolve though so I assume they use borate and/or potassium hydroxide.

Azoles coat the entire copper surface, which might interfere with heat transfer. The OAT coolants for autos that uses 2-EHA (e.g. DexCool) say the corrosion inhibitor only works when needed (when there is corrosion starting) rather than coating the whole surface. Tolytriazole, common in auto antifreeze and responsible for its strong odor, also apparently forms a thinner more hydrophobic film than benzotriazole so it may be better for our purposes.

Auto antifreezes, aside from usually containing toxic glycol and unnecessary dye, contain things like 2-EHA (a problem with silicone gaskets), silicates (sludging and heat transference interference), phosphates (scale formation), etc. I don't know if our water pumps are safe with 2-EHA, the "organic acid" corrosion inhibitor of most OAT antifreeze formulations. If not then it will eat the seals. If they are safe with it then the next question is "Is the concentration of 2-EHA high enough to withstand dilution to 25% and/or does it need to have the pH raised to keep it stable and effective?" All auto antifreeze is designed to be used at no less than 50% dilution.

The ideal glycol coolant for our purposes looks to be 25% propylene glycol, tolytriazole (high purity to avoid the odor problem) and/or benzotriazole, molybdate, and possibly tetrasodium borate and/or potassium hydroxide to buffer pH to around 8.5. Alternatively, a non-glycol system could be nicer since we don't need the freezing protection of glycol and propylene glycol doesn't give the same level of biological protection of ethylene. It also degrades in the presence of air.
Edited by superstition222 - 10/7/16 at 2:41pm
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