they contain the micro and secondary trace elements,i would use it(bloom) on the next feedings,as far as a ph down,i use nitric or phosphorous acid,I've never used vineger,aquarium testers are fairly reliable, If i may make a suggestion,"pyrosol"from general hydroponics is an excellent additive,it contains most of the necessary micro &trace elements,and is a good soil conditioner,....bonbon http://www.altgarden.com/site/additi...s/pyrosol.html