Now without any prior experience, and given what you see/read about on the web, that all the symtoms appear very similar, what are the odds out say 20 possible things it might be(could be more or less), that you will get lucky?
Not much.
Now if you use an EI approach, that rules out many things.
So you really are left with general maintenance and CO2, if you have enoghyb light and not too much and 10 hours per day, all that remains really is patience and CO2.
That makes my job and growing plants much easier.
It also allows me to isolate things very effectively, same with anyone that wants to delete say just PO4, or just NO3, or just Traces, or just K+(few folks do though, because few have non K+ based NO3 and PO4, although sodium based salts of NO3/PO4 and Ca(NO3)2 are easy to acquire to drive the K+ down.
So many never know unless they try to do it on purpose what K+ issues look like or not.
You also cannot use TMG, it has K+ in it also.
So what I am saying, if you add ferts, it's not likely you have K+ issues in most cases.
K2SO4
KNO3
KH2PO4
TMG
All add K+
Regards,
Tom Barr