I've been researching these spots and I have myself convinced that it's Mg deficiency, then K deficiency then Cal deficiency... and well, I don't know what the heck to think! This is a bubble bucket grow, using city water adjusted PH 6.8- ppms 650- GH products and schedule. Thanks!
In my experience, that type of damage I used to see it when ever the plant has the Calcium Lock-out. In my case was due to my Tap Water, it is consider HARDWATER PPM@275+++ Advice: Flush your plant and start over with Distilled Water (PPM@0) I used to bought the gallon for .65 cents from my Local SuperMarket. My 2 Cents
I think you may be on to something with the 'calcium lock out' - cause this problem popped up after I switched from distilled water. When you say calcium lockout, do u mean my local water source has so much calcium in it (ppm 250) that the plant locks it out? Do any of you know reference material that reviews water quality reports and its effect on hydro setups? I have a water quality report from my city but I'm not entirely sure how to read it, or what to look for. btw- calcium values show ppm 89 - 175. And my Jorge Cervantes reference says this Calcium value is 'good' ppm 100 - 150. What gives? Thanks!
Is your PH 6.8 after you adjust or before? If your PH is 6.8 after your adjustment, then that is why you have the Calcium deficiency.
I guess I'll give it a few days and ride the PH level down. Or should I flush with distilled and redo my nutes and cal/mag? Thanks for all the fantastic input!
Get your ph down now...no need to ramp it down slowly... You may have to add a shitload of ph down to get it there so you'll have to watch your ppms... Personally, I'd mix up a fresh batch of water/nutes with the proper ph and do a res change, shouldn't really be much need to flush unless you continue to have problems IMO... If you're using tap water, you might not need to add cal/mag...concentrate on the ph first and see if they respond...
Yep,, Get that PH Down now.. Dont wait cause your pic looks like they are pretty bad. Not only are you locking out calcium with that PH, but your locking out just about everything else.
Ignorant fool is spot on... that is high ph damage..those leafs will not heal.. get ur ph down to an acceptable range..5.8 - 6.0 and within a week you should see new growth....
Sorry I did not realize you were talking about Hydro. I assumed was Soil and PH@6.8 did not seems abnormal. All the farmers above are absolutley right. Due to your PH being high for hydroponics, therefore Calcium Lock-Out. The thing I love about Hydro the most is, You will improvement almost instantly in the new growth.