ph question

ok, here my question. running hydro and rockwool cubes. the rez ph is saying 4.7 and the water running off the cubes is saying 5.3. my ppm are saying 1050. i am using hanna checker ph and using hanna primo ppm checker. should i empty out the rez and just run water threw to flush . oh yeah and its in bud.

The best way is just to make sure that what you're putting in is already balanced. Gradually, your soil ph will adjust to the ph of the elements being added to it, so if your water balances where you want it (should be in the 6.8 area for optimal nutrient absortion) then the plant's health should reflect.