Originally Posted by JackNaylorPE
I notice in most threads I read here where the subject comes up.... 6 months seems to be the average for DW builds.... ya water is no longer "deionized" within 1-3 weeks of install. Those w/ coolants seem to go longer.
Originally Posted by bombastinator
well of course not, but does it matter if it is? I always thought the point was to get pure water. deionized water is distilled water. Pure H20. The whole point of the silver is to PUT silver ions in the water to keep bacteria from growing. You could us antifreeze too. That stuff lasts for many years in cars which work it a lot harder.
With hot water radiators in houses you basically NEVER change the water. You want to leave it in as long as possible in fact, because the air dissolved in the water eventually precipitates out leaving what is called "dead" water which is much more efficient as a working fluid. It turns grey and smells nasty when you take it out of the system, but is that really important?
distilled water and deionized water has very little difference in purity. I emphasize legitimate because some areas local distilled water suppliers have very inefficient units, or perhaps they aren't cleaned properly, and sometimes have very... let's call it impure distilled water. Deionized water is, what else, distilled water that has had all, or at least the vast majority, of it's ions removed. This makes it inherently dielectric. It will
re-ionize after time, once again becoming an electric conductor. Deionized water is also inherently Ph neutral. One major issue with deionized water is it is prone to reacting with carbon-dioxide creating carbonic-acid lowering it's Ph. Another... I won't call it an issue, I will call it an irritant, with deionized water is it is near impossible to get a proper Ph reading, as Ph testers test the hydrogen ions.... Deionized water has no hydrogen ions... It can get various readings with very different ranges from back to back testings.
expect to keep algae out of your loop purely by using a pure water form with no biocide. It WILL find it's way in.
As a side note, silver coils do NOT work by releasing silver ions into the loop. Contact with silver prevents a cell membrane from absorbing oxygen, effectively suffocating the cell. This means there DOES need to be an active flow over the coil to keep it functioning as a biocide. Even then, in deadzones in your loop algae CAN still form, though it's very few and far from when it happens. If someone claims they have never had an issue with silver as a biocide after leaving their loop off for a long time, then it's simply because there is no living algae remaining in the loop. Without living algae it can not reproduce.
On the note of using ethylene glycol (antifreeze) as a biocide, that is a very prevalent additive in concentrates and many premixes. The problem is it is HIGHLY toxic... It has also been linked to microfractures in acrylic when used in moderate/high concentrations.Edited by ZytheEKS - 11/11/13 at 2:34pm