Yes raise it.

Also, 5.2 is a bit low for hydro setups.. keep your ph more in the 5.8-6.2 range.
ninfan77 Reviewed by ninfan77 on . Rinsing root system with H2o2 solution When I mixup a solution of H2O2 and water the Ph lowers to 3.2. Should I bring up Ph to normal levels 5.2-6.0 or should I leave it at 3.2? Will H2O2 solution work if Ph is raised? Rating: 5