whats baking soda gonna do?Iv heard something about a Baking Soda mixture , spray it on the leaves and let it settle for a day, Please look up on this more as i have never put it into practice.
Used one what? pH meter? pH for soil grows should be around 6.5, mine is usually 6.4 without adding anything so I just keep it thereso what ph should fix it cos ive never used one with any of my grows