Vinegar isn't ideal but it's better than lemon juice and CERTAINLY better than urine (guaranteed to burn the fuck out of your plants with available nitrogen).

You will have to play around a little bit. What I would do is since your runoff is 7.5 and your nute solution is 6.7, first of all flush your plants very well with water at pH 6.5 just to remove any salt buildup. And check the runoff at the end of flushing. Then make a fertilizer solution at 1/4 the strength that you usually use, and adjust the pH down just a little lower than your goal. I would shoot for between 6 and 6.3. Water with this until it runs out the bottom of the pot, and test the runoff. It should come down.

Edit: Do yourself a favor and pick up some pH down for the future. And cider vinegar is the best for your plants... something to do with soil beneficials... but I forgot what! :jointsmile:
stinkyattic Reviewed by stinkyattic on . PH question Im on my fourth grow and decided to start troubleshooting everything and taking a more detailed approach to my growing. I have noticed that no matter what I do to my plants (light, air temp, ect) they seem to take forever to grow and my yields are good, but for the most part small. I cant seem to get my buds to fill in densely. Im only growing 2 plants in a 2'deep x 3.5' wide x 4' tall cabinet with a 150 watt HPS lamp for flowering and 3 "150watt" (23watts) CFL blue spectrum bulbs for vegging. Rating: 5