Yes. Citric acid isn't the best option, but it works in a pinch. Not sure I'd use it often or for prolonged periods, tho. A better option would be something like General Hydroponic's ph Down. (phosphoric acid)
Do you have a method of checking your ph? Just curious, because a simple test would have given you the answer.
Rusty Trichome Reviewed by Rusty Trichome on . ph ? is it true lemon juice will bring the ph down? Rating: 5