111.8 mS/cm Calibration Solution

I am giving this solution a neutral review. I got this and tried to calibrate my TDS meter used for hydroponic solution mixing. Alas, this is a much, much higher concentration used for very high TDS / EC(conductivity) like those found in Wastewater/sewage testers. I ended up getting the 1413uS/cm solution for my needs from the same company and it worked great at calibrating my meter. I love the 4 bottles so that once one has been contaminated and is no longer calibrating accurately, it can be discarded and another bottle used. I gave 3 stars because when the product arrived, 2 of the bottles were wet. The plastic coated paper seal had been ruptured around the glued seal and the solution was able to exfiltrate a bit. I assume this would have contaminated the solution somewhat.

Although the delivery was quite quick, the pruduct is contaminated with what looks like mold. Outside of the bottles were quite dirty, I suspect the product was on shelf for a long time.