yea my nutes buffer the ph also, if it drops add nutes. the life span of my nutes are about 15 days, so i change my res ever 14 days, not much guess work
but yea i really do need to get tds/ec metter, but as you can see im one cheap mofo.... haha for now just reading what my plants are saying is working out pretty well.
im deffinatly upgrading for the next grow tho(tds metter, beneficials, better line of nutes, maybe a bigger system also), this run is basically to see if im capable of learning enough to make it work haha