ROB MCLURE video on Cory Cats

I just took a couple things from his talk and improved my success with cories. I bought a TDS meter, then I purchase white play sand from Menards and ordered alder cones off ebay. My cories are happy and spawning. Of course I am doing weekly water changes. I am trying several other things, but time will tell if it makes any difference. I have watched the video twice since hearing him in person.