Koi Forum • Jap Mat v Cheapo blue Mat : Koi Talk So? Whats the difference and is it worth the extra pennies? Or is it just another case of adding the word “Japanese” to the title and charging more? I have always used Jap mat in my filters and am modding my setup to lose the useless flocore in the last bay and switch to yet another bay of jap mat of some type. I am aware that there is a denser type of the matting using in the erics and also a green type (not sure on specs for this though) Wonder if someone could point out the differences in matting types and pros & cons for each?