oh dear.....yes, up your ph asap......Fresh RR's would be a good idea if you can spare them .......have any seeds cracked at all? If not, place them in new rr's and change your ph to 6.0 if you are going to go hydro and 6.5 if you are going to grow them in soil.
RR's contain all those little beneficial mycorr.....??? (Stinky...help....) and things that help resist mold and fungus and a ph of 5 probably killed all those little helpful things off.

Good luck.