Big oops.....non-pool antifreeze in water :(

[chem geek]

Does EG break down? I thought I read that it does actually break down in water over a period of time (like 4-5 weeks). Since winter up here in CT is a lot longer than that, I feel we're safe for next year.

Antifreeze doesn't break down as quickly as you say (at least not in pure water). If it did, then mixing it with the water in your car's radiator would not last through an entire winter. Generally, antifreeze (either by itself or mixed with water) is supposed to be replaced every 2 years (some special types of antifreeze last up to 5 years, but not EG or PG). It does eventually breakdown into carbon dioxide and water.

Since EG and PG are small organic compounds, they could very well be oxidized by chlorine (to carbon dioxide and water) and would very likely be oxidized by non-chlorine shock (potassium monopersulfate, aka KMPS). So if you are REALLY concerned about this (and I don't think you need be), you can put in a shock dose of chlorine and/or add KMPS to ensure that you've destroyed all the organics in your pool, including any EG or PG in your pool. The only reason I bring up KMPS is that it oxidizes organics better than chlorine (whereas chlorine combines readily with ammonia, it combines more slowly with various organic compounds, depending on the specific organic, whether it has nitrogen sites which EG and PG do not, etc.). Of course, the chlorine will have all winter to oxidize the EG or PG so it might very well do the trick without any need for KMPS. I'm just giving you options depending on your level of concern.

Richard