I just calculated this out using Metricide 14 (2.6%) ... someone please check my math ... if I use 10ml/day of Excel .. the equivalent I'd use of Metricide 14 @ 2.6% would be about 6ml/day.
There's 3785 ml in a gallon. So 3785 ml ÷ 6ml = 630 days ÷ 365 days = 1.7 yrs. So a 1 gallon jug would last me about 1-3/4 yr and only cost $24.04 shipped! (ebay item #230818682873 ) That's a huge savings over Excel!!! If I did my math right. LOL
I had to Google the shelf life of Metricide just to make sure it wouldn't expire before I used it all. That didn't help much so I emailed the seller to ask what the expiration date is. I wouldn't have thought of that if I hadn't noticed a couple listings that gave an expiration date .. one for Metricide 14 with expiration of 8/13 .. that one would expire before I could use it all. Mostly I don't want to buy one that's already expired .. you just never know when you buy from that site.