i had tonnes of this crap like covering my tank like a month ago. its totally gone now! it was like so annoying.
do not, i repeat, do not, buy that red slime remover crap. red slime is like some kinda bacteria (sometimes its called red algae but it aint algae). that red slime remover crap is basically an antibiotic and it like totally kills all bacteria indiscriminately, meaning you end up killing all the good bacteria also.
in my opinion, wait it out. just keep on keepin on like you would. to be honest, i think what happened with me was i said screw that RO/DI water crap, i'm gonna use tap water and "cure" it with that "prime" stuff. after that great idea, i started getting that red slime stuff. so... i gave in and started buying that RO/DI water and after a month or so, the red slime disappeared.
i had to like clean it like all the time though. that was like a total pain. it was covering everything! and it like only took a day to like grow all over. i used a turkey baster. turned off all the powerheads, and like turkey basted all that red stuff. i think its also called cyano bacteria. anyways... just my thoughts.
xoxompty