They look very small for a 5 week veg. Is that 5 weeks veg after seedlings or 5 weeks from day seed went in? I assume seed since if clone for sure would be much better. Your ph is way high should be in the 5- to no more then 5.8 range 5.5 is ideal in hydro setups. Higher slows growth and causes nutrient usage and uptake issues so get that ph down quickly. Not sure what nutes your using so the ppm is an unknown. It would be way low for my grows using Fox Farm nutes or Humboldt nutes or Canna.