I have serious plant problems... Please help!!!

Hi,
I'm growing two white widow plants, and one of them doesn't look very good.
the larger leaves have gone dark, yellowing round the edges with brown dots where the yellowing is and they are drooping downwards. The newer leaves are drooping downwards really badly but have no yellowing or brown spots.
then today i looked at the plant and right at the bottom where the leaves are growing i saw a few really bright completely yellow leaves. I picked them off but im really worried about the plant.
The other plant looks really healthy but the leaves have started drooping downwards but no yellowing round the edges.
I am feeding them Iguana juice grow at the moment under 18 hours light per day.
i want to put them into the flowering stage soon feeding them iguana juice bloom but with the way the bad one is looking i dont no whether to or not.
Please help!!!!

Thanks

Hydro or Soil?

there in soil

Often in soil I had nutrient problems and most of the time it was due to Ph problems, I also used FFOF too since then I switched to hydro and no more Ph problems. It would be nice if u could post some pics, but it could be nute burn even though its hard to do in soil but not imposible. Are your tips burned? Is that fertalizer organic?

right. yeah some of the tips are burnt and i tested the PH which is 7.

oh and yeah the nutrients are organic

View attachment 1334952

That seems a bit high, try and get it down to 6.5.

I doubt it is fertilizer burn because organic nutes usually just sit in the soil until the plant needs them they dont burn unless a extreme amount is used. I would just focus on balancing out your pH maybe get some Lime or some Potash I believe Potash lowers pH might want to look it up.

ok, cheers