Peat Based Compost - ph issue?

Could peat based compost be the reason my Friends plants leaves are curling and twisting with a lighter green center?

How can he adjust the ph? Could extra perlite be added to the mix as to dilute the compost substrate? Should he fertilize during this time?

Really frustrating... the plant looks like its hugging itself.

PLEEEASE help!

i'll chime in since no one has answered yet, not sure how much help i'll be
what are the proportions, how much peat?
used a lot on RIU with good results, but i have seen a few growers that don't think that much of it
claim it kills the beneficial bacteria, can't say that for a fact though
you really need to get a handle on ph, ph drops or test paper can be had for $5 at many stores

growone

it could be overwatering...or heat stress...you can never have too much perlite. are there any drainage holes in the pot?