Arxpreacher

It appears that some in the container were defective. Followed instructions as before and I tried again this evening and the third strip changed color. Finally cooking with gas!

Totally cleaned and re-stablished a 55 gal Community Aquarium; currently being cycled. I have used API testing chemicals in the past but decided to purchase the AQ-COOP multi test strips. They arrived and I followed the instructions and after trying three strips, they remained the same, no color change, no reaction to the water in the aquarium. Any suggestions?