I need to save these

How do I save these plants
600wt lights
Cocoa / perlite mix and
Floating roots watertable.
GH flouro
RO Filter
69 t0 78 degrees
Ph 5.8 to 6.4
Plants get thriving and kikn butt. About a month into bud when everything looks awesome they begin to mimic Mg deficiency. The brand of nutes don’t seem to matter. The more nutes I have the longer it takes to develop the problem, but now my nutes are at the peak i can give em while the problem grows. The leafs that see any light start to get little spots til the outer vainal areas bleach and the leafs die. I'm looking from the underneath now and the spots are like transparent. I can see the light thru the spots. Soon i'll be able to see thru them. What it is is the whole plant seems to just want to frign die with deficiencies almost suddenly. I have been having this happen too many times now and I seriously need help. I thought I had it figured out when I dosed heavy with cal mag and they thrived. Til now. AGAIN! I'm now folier feeding with epsom salt. Another forum friendly person mentioned airborne toxins. They’re symptoms were like mine. I did find some toxic vapors nearby and removed it a day ago. I kinda hope that was it. I’m tired of staying up late trying to salvage this once easily grown weed. I have one plant in the last few months that doesn’t seem to notice. It was an experimental the was in 3 gallons of soil then put in a 5 gallon with cocoa and perlite. I treat it like a hydro plant. And feed it floronova full strength. It looks slightly over watered like expected.
But how do i save the others? your time spent will be really appreciated and Karma will pay you off some day.

 

in the bottom you says that you recovered one in SOIL.. There you're answer, Pull em and replant them ..
you might be over doing the Magnesium also..

Pics would help

What kind of 600w light we talking here? using full HPS in vegetation state will cause leaf yellowing..

 

I have 3 600w hps over 3'x7' tables. I have one off and am running 2 over each as they are stressing under lights. I have them about 20 inches or more away now. I am watching the Mg and that's why I folier feed the epsom. It was keeping them going til now. it seems that one month in bud is when it triggers and I can't get a grip on em. A large percentage of the leafs are bleaching and dying fast now. I haven't figured out how to post a pic in this site. Leafs in the light have green vains with dead between.
Thanks keep hitting me if you can think of anything.

 

is it low in nitrogen ?
Root bounds? see kinda hard to help yea; cause no pictures. but I have suffered the same symptoms in a month..
Ive really noticed it when all hps is the only lamps in flower, and to much bloom fertilizer . you can load a picture on a image share and paste it here..
seems like a drowning also?

 

Low N? low n plants just seems to yellow a bit. These are just burning under normal lighting. Like the light is the enemy. Perhaps they are being vampire like.
This happens in different mediums. water or cocoa/perlite. I've been reading for hours and all I can find is i need more Mg. Last run i used like half the nutes i'm using now and it still happened. I thought it made it worse. This time i use gh but then i add so much cal mag that the nutes are less so i can achieve my desired ppm. I do have one plant sitting in there that is half soil. It's not yet effected. I think i need to find why the Mg isn't being absorbed or used.
I'll get some more pics and post em. Thanks

 

your light might be the enemy.. Try putting up some MH metal halides, to bring back the greens in the leafs.

Mg, I always dissolve in hot water first..

 

i do have old bulbs

 

that only slightly matters with HPS Lamps, When they die , they die... arguable they lose some lumens with age, but will not twist spectrums to harm plants..

I still think your flooding with water to much .. lower on plant are knowns to wilt when in flower but not so severe in the beginging..

 

once you overdo the magnesium the damage is done. it fucks the roots up and makes it hard for the plant to absorb any nutrients especially the magnesium itself. therefore making recovery for the plant difficult even after you switch the nutrient solution.

and i agree,that very well could be the case..

 

I use MG very sparingly,, Im sumwhats old fashioned, natural soil, peat, verm, little worm cast and straight water ..
I take that soil out the bag mix up on tarp and keep them nutes at a minimum.. during flower many I dont touch at all with fertilizer, where others I burn the shits out them, just cause experimenting is fun, if you have the room.

 

http://img197.imageshack.us/img197/8715/mangoclose.jpg
http://img192.imageshack.us/img192/7105/sampleh.jpg
http://img189.imageshack.us/img189/7163/seethespots.jpg

 

http://img197.imageshack.us/img197/8715/mangoclose.jpg
http://img192.imageshack.us/img192/7105/sampleh.jpg
http://img189.imageshack.us/img189/7163/seethespots.jpg

 

you made them sound a lot worse off then they look. id think its more likely an excess of nutrients then a lack thereof.

in my experience, the hps bulbs tend to be a bit harsher on the plants, and most of my foliage issues arrise during the flower cycle with these bulbs.

Id suggest backing off the epsoms a bit, and continue your normal N-P-K dosages (doesnt appear to be an issue related to those nutrients).

in my experience, if you can complete a flowering cycle without having many of your fan leaves burn or die off, youre on the right track.

 

yeap,, that MG over done... hold the MG .. Imo stick to straight water with some bit of N..
dont look to bad either..

 

Well the pics make them look good but they were looking perfect two days prior. The damage to the leafs occured suddenly and I'm trying to get a jump on them. Last run they died so the urgency is real. I want to know why I should cut back on mg. I give them cal mag but I'm pretty sure I didn't overload mg. just that I have to give them cal mag when I use floro micro 1 , and floro bloom 2, which should provide enough mg is the mystery.
Thanks

 

if youre actually providing Mg, then its highly unlikely that they are getting too little of it.

ive had many successful (though not perfect) harvests where i used only primary nutrients (organic however, so Mg mayve been enough from that), and had no real issues with magnesium deficiency. plants need a bit of magnesium, but only a very small amount that barely requires a purposeful application of epsom, especially in multiple doses

 

I had minimal additional mg in other good grows. mg problems came to me and they are working enough to improve but not enough to fix it. This set up is requiring an unhealthy amount of mg. Something changed and the process of elimination to find the prob is almost complete. Things are always found in the last place you look for them.
straight water with a little N? Sounds like a good experiment. Ive not heard that before. I'm gonna try it on a plant. i do alot of gh light 1-1-1 on vegging. Ive had good simple runs with ease before this. Ive even felt a little guilty for not even knowing how it worked. It just did. But I'm committed as a mofo to fix this frkn prob.
Thanks for helping

 

One table died the other dying. WTF

 

Sorry to hear about your loss but very much the old snow ball effect. Once you lock up ya nutes a plant can look healthy one day and then in 3 or 4 be gone. In a soil grow ya would of flushed out and started again on a reduced ferts. Dont think you said but what npk and trace elements is your plant food ratings?

 

why do you think its an underdose of magnesium? you realise your other healthy grows required little or none, and that this one is getting stupid amounts of it, yet you keep claiming its an underdose.

STOP FEEDING THEM MAGNESIUM-NUTES.

flush the medium REALLY well, and use only un-fertilized water for a few days, then resume your normal regimen.

an underdose of nutrients will make a plant look weak, less-than-ideal, and maybe even a touch sickly. BUT ONLY OVER-FERTILIZING will kill your plants (obviously there are some exceptions, but this isnt one of them)