More newbie questions - black tank flush system

the idiot lites are just that,i knew that waz comeing here too.so startyed watching how much waz going it the tanks incase the lites were wrong.so tried the cem called I----c----e--. only if we were leaveing from this stop to the next, and in the warmer temps.works great. the idiot lites aint much good. I guess the technology aint there yet.the ice works great, and don't hurt a thing. now its all happy-camping