Plants sick

Couple clones turning yellow and bigger plants dying. Help would be greatly appreciate.

Whats your ph and water temp and nutrients etc

Ph unknown waiting for new meter, water is around 18 c, neuts is Miracle-Gro @ 150ppm

I find ph is the only real worry when mines off it affects my garden quickly i always have to ph down my tap water. . I never used miracle grow for hydro before it always wrecked my out door garden and indoor plants so not a fan you should use flora series micro, grow, bloom. Its cheap and really easy on hydro. But u need to get a ph check its prob causing a nute lockout.

What do the roots look like too? You could do a cal mag foliar feed very light dose till u get ur pen but i would deff be wanteing to get the ph. Even fresh nute change but again u need to know ur ph if your in a city they will have your local water avg ph on thier site and u could guess what to do from there.

Ph is @ 6.5