Help my plant is sick

Ok so I just recently noticed that one of the tips of my plants leaves have been turning a slightly brownish yellow color and a slight crisp to the tips as well I am a total rookie here and I have no idea what I'm doing but I read online to back off of nutes and hit ur plant with straight clean water so I dumped some distilled water in there today And I hope it helps anyhow if anyone has any advice plz help here cause I don't know what I'm doing I'm a total newbie on this stuff

Nute burn, cut back a little bit.

Its not that bad yet, nice emerald color still. Ya, i agree on cutting back. It does look a little like nute burn on those tips and since those leaves still look great the plants telling you that it has enough nutrients right now. I hope they dont get much worse. Flush them with three times the amount of water as yout container holds and they should be ok. Nice lookin girls, they should be killer.

Thanks everybody for the help I will only give them water from now on its only on one of the plants so I should be ok I was just really worried ya know but I will hit them with a lot of water the next time I only use distilled water and the last time I watered them I gave them some cal mag and super thrive should i still add that or just give them just distilled water only I usually feed them with cal mag, Superthrive, flora blend, Epsom salt plus, and seaweed extract that is when I feed them but ever since the problem occurred I gave them one watering so far of distilled water Superthrive and cal mag so my question is should I just use plain distilled water without anything for a few weeks. And these are the rest of them the whole set I got right now