HYDRO Babies in danger?

[Geezis]

This is this morning. I’m a noob, not recognizing the issue with my little guys. Thoughts? Fixes?

 

[Eigholte]

Keep in mind I'm not a hardened expert, and I am having a bit of a hard time with the color in the photo, but the lightening at the tips reminds me of my first grow, where my plant had a pretty sudden pH shock.
Are you measuring your pH on this grow with something reliable? (My issue on that first grow was a broken pH pen leading me astray and resulting in watering with 4.0pH nutrient solution. Whoops.)

If it's any reassurance, I was able to recover from that, though the plant in question did have a reduced final yield.

The pH issue caused the color change and die off on the lower leaves seen here:

 

[Geezis]

It could very well be the pH, was forced to use a different water source for last rez change due to a broken water pipe near my house. And, of course, I’m awaiting a new pH pen from Amazon, which “got lost”. Any suggestions on a quality brand? I really need to get my stuff together, building a DWC grow room at the moment.

 

[Graff420]

Mine looked the same and then I took the top feed drip line off one of my girls and she cleared up right away while the other continued to shrivel and dye but I saved her not ulsure if your useing a top feed drip system but apparently when the roots come out the net pot you must pull it away

 

[Geezis]

I’m trying to follow the bubbleponics tutorial from this site, which says its fine to leave the top-feed running throughout the entire grow. Maybe I should shut it off for a few days, see their reaction. Thanks!

 

[alltatup]

Can't really see the plant in that light, but it looks like nute burn. I use an HM DIGITAL PH Meter PH-80.