ph problem

i have currently set up a intelligent watering system flood and drain and am growing in clay pebbles for the first time. i have set the ph in my water butt at 5.2 but when the system is flooded, i check the ph in the pots and it reads 6.2. should i ajust the ph in my butt to 4.2, as the reading in the pots will be 5.2. i washed and soaked the clay pebbles for 2 days in a ph of 5. any help will be much appretiated.

6.2 should be alright, I don't personally do hydro but have done alot of research on the matter and found that best levels are 5.2 to 6.4 so you should be good unless your plants are having a reaction? then you might be having other problems that don't stem from ph levels.

Something is naturally buffering it to 6.2. That is not a problem and over time it may drop on its own. Do not lower to 4.2.