Round Meadow Lake in Hidden Lake Forest Preserve in DuPage County, IL

This lake is still nearly entirely frozen, but there was some free water around the edges. The Cl test result was very low, perhaps because of this. I had to estimate the ppm because the units were too low for the card. I had an almost entirely frozen situation one time last year, and it also had quite low Cl, although not as low as this time. The consistent no-ice reading has been about 4 units, and this time it was about .8 units. The previous icy time it was 2 units.

The lake was mostly frozen over, but by moving about 100 yards away from my usual site, the ice was thinner, and I could get water. There was significantly less chloride than any other time I've tested this lake.

I did two tests today to check accuracy of the test strips. It rained pretty hard for about 30 minutes just after I started the first test. I waited until that was over to do the second test. The second test came out a little higher, and with rounding up, I reported it .2 Quantab Units higher (14 ppms). The first test was at 154 and the second was 168, so I averaged these and reported 160 in my results above.
Please let me know if I need to do this another way. I wasn't able to do two separate observations.