please help with these 3 plants they look sick!

maybe suffering a nitrogen problem...should i give just regular ph'd water 2 6.0?

Looks like a magnesium problem to me. But you really need some better lighting for some pics

Indeed. It is a magnesium def and it's loo late to fix it. I'd suggest you get a calcium/magnesium supplement for your next crop.

Daaaaamn.....weellll I went ahead gave them plain water...I hope this doesn't ruin them....I have Sensi cal grow n bloom. I've been doing 20ml per 5gallons...so safe to say I wasn't using enough