Help! Soil ph too high

[Diesel200034]

Ok my first grow and my water is ph to 6.4 I’m in fox farm soil happy frog ,and I’m in veg stage 3rd week . I’m not see any signs of stress or discolor but my run off is really low like a 5.5 so I did a slurry test and shows like 5.3 I’m just trying to catch it before anything happens .also I’m using fox farm trio 1/2 strength same ph ppm around 400-500

[Rwise]

Sounds more like the PH is to low and needs to raise to 6.2-6.8. One can add many things to raise (or lower) the PH such as dolomite lime for a PH up buffer. Wood ash ash can be added, potash can be found as a PH up and feeds the flowers (so does wood ash).
Also are these autos or photos?

[Diesel200034]

Ok thank you they are photo widows ,i ph everything going in to 6.5 , I did read about the lime but I have not heard about the wood ash . Would you know how much to add ? To raise from around 5.3 is what I got from slurry test

[Rwise]

Mostly I put the needed things in the soil and let things happen on their own. Adding wood ash gives a PH up buffer (as does the lime) but it also feeds the flowers (as does the lime, but different) if you simply put the buffers in the plant will move certain things around to control the PH. I would also raise the feed PH to 7.0 until the PH comes up.
I build my own soil, add in the buffers and etc. though it is a living soil I do test the PH, just in case I screw up.