Yes you can, as long as you didn’t go overboard with the initial correction. If you added 10x more than you should have, there is no good way to fix the nutrient solution and sadly you’ll have to start over. If you went just a little too far, mix the solution well and correct it again to the proper pH. You never want to mix pH up and pH down concentrates together but if you over-corrected the nutrient solution, it is safe to correct the reservoir again in either direction.
See Also
Maintain Your Pool with Baking Soda | Arm & HammerpH level in water: a crucial pool maintenance aspect - FluidraConsequences of a too low pH levelFrequently Asked Questions | Swimming Pool Maintenance & Pool ServiceUpdated on November 11, 2019
