I'm not the equipment expert around here and can't really help you with your DE filter. (I have sand.) If you have to put it on recirculate for today while you wait to get the filter working properly, I guess that is better than nothing. Go ahead and get some Borax in there ASAP and then some bleach. Hopefully, someone will come along who can help with your filter. Chlorine can kill the algae but you're gonna have to have a working filter to get rid of the dead algae.