high pH

[coldandwet]

thanks for the input on geting ph down. my resivior is also near 8. my 70 gal.system is flood and drain type. I have it cyceling once every 3 hr. 24 /7.as Iwait for my seedlings. when I go to add fertilizer @ 1/2 strengh won,t the ph automaticaly drop a point or so? my nuit. are also heated to73 de f. and airated. any reply on subject greatly apprecieated.