nute lockout?deficency?light?ph? need help xD

[paranoidperson]

yesterday I started seeing some light yellowing on the tips of new growth, I think my plant is transitioning in flower, but I think it's too early (22 days old plant) anyway it started showing pistils, my prediction is that the light is too close to the plant, viparspectra p 1000 at 66cm from top of the plant, I lowered the light to 75% power bc I cant rise it more xD, I have to modify my closet, also I don't have a ph pen soo I dunno the ph, but according to the water company it should be from 6 to 7, also I didn't gave the plant any nutes, I used a very rich soil (biobizz allmix)
temps can get a bit hot but never over 30 celsius or under 20/19.5.C

thx for your time <3
/edit/
I have 3 plants, one is 8 to 10 days old and it's good, another one is the same age as the plant on the pic but is shorter in height and doesn't show any sign of yellowing or anything

 

[2Bad]

Light stress but I mean that's fine light white tips are normal if it worsens or your plant looks said youll need to lower the intensity percent

 

[paranoidperson]

Light stress but I mean that's fine light white tips are normal if it worsens or your plant looks said youll need to lower the intensity percent

or either raise the light, got it, but anyway even if the light is close and lowered light intensity, that does mean shorter plant/lower yield? or not