for the purple stems . usually a sigh of HIGH ph . are you checking it ? what is it ? need to know if your hydro or soil . ph is different in both . I bet your way over your desired level
what is the ph ? 6.5 or ? and I would wait to they are a foot tall under t5 . and taller its a waste light don't get to the bottoms . perfect size for t5 they will be 1.5 foot total height when they are done around that .
No oh water is in good ranges in betwwn low 6s n high 6 in soil I have 8 so far 3 I just transplanted into happy frog soil from incubator the light set up is a 4 bulb and strip t5