i got some ph down and up. my ph is 6.7. i was recommended that this was fine but another person told me to get it to about 6.2 or 6.3. so i was wondering how to use the ph down? should i just mix it into the next feeding? by the way im using 10gal pots and i feed once a week 2 gal feedings. with fox farms nutes. and tap water that sites out for a few days. soil is a 50/50 mix of ocean forest and sunshine mix #4.