[nuggluvv]

A little background info...

Seeds or clones, source? clones
How old are the plants? week 4 bloom
How big are the plants? 20"
Lighting wattage & distance? 1000w @ 2.5 ft
Soil ingredients or hydro system? hydro
Container size? ebb & flow table
Watering frequency? How do you judge this? 1 hr 4 times per day
Fertilizers used and how often? SuperBloom A/B
How do you ventilate the space? Active exhaust
Other details? Include photos if possible.

I have included 3 pictures: one showing early signs, and two showing later signs. Veins of affected leaves and entire plants red (not due to strain, but unhappiness). Problem begins with interveinal chlorosis on older fan leaves. Then these leaves develop necrotic regions, but generally not on leaf margins (but from center of leaf).

Plants suffering from what appears to be mixture(?) of deficiencies. Mg most likely as best I can tell, but uncertain. Must stem from problems in root zone. Roots rotting in tray, covered in dark brown slime. Could this be due to cold res temps? No res thermometer, but it's pretty cold in the basement (concrete floor, but res sitting on piece of insulation.

Atmosphere not as constant as in times past. New room; not all kinks worked out yet. DIF (difference in night and day temps) is around 20F. Gets down to low 60's F at night.

Grew same strain a couple of months ago with no problems. Any assistance greatly appreciated.

[fooldall]

The intraveinal chloriosis and the rust colored spots and eventual necrosis leads me to believe you're spot on the Mg def diagnosis. What is your pH, and are you using Tap water? I had a simliar issue when I was having problems with pH flux AND a large amount of calcium in the water. Add a pinch or two of Epsom salts in your next res change and see if the problem halts.
Some yellowing is to be expected in the final weeks of flowering, but what we're seeing here is DEF an Mg deficiency- then again, it might be due to the root rot you're experiencing.

That brings up another question - how often are you changing your res?

[nuggluvv]

Thanks for the quick response fooldall.

That is the strange thing. I use RO water (water around here sux), and reservoir changes are occurring every couple of weeks. I will give the epsom salt thing a try, but I have also added CalMag Plus to the solution to try to alleviate the problem.

Mg is less available at lower pH values, and I have also had trouble keeping the pH up. This is in contradiction to what normally occurs; as with most hydro systems, I am generally having to bring the pH down a little every few days. It seems I read somewhere that this could be a sign of a K deficiency also?

Anyone think that cold res temeratures cold be part of the cause?

Thanks for all the help. Let's learn from my mistakes together.

[nuggluvv]

Oops, I also forgot to mention that the entire stalk and all stems of plants are turning red. This is not an attribute of the particular strain either. Any thoughts?

[Sleepy]

i think if you are suffering rot at cold temperatures, the system needs a good cleaning...and more frequent reservoir changes.

be careful that you do not have a Mg overdose from pH out of range...

calibrate meters, CLEAN EVERYTHING (pumps, hoses, etc...)

whatever you do, it will take 5-7 days until you see improvement...

before adding anything else, i would correct the pH and rot issues.

best of luck.

Use a more complete fertilizer regime, and back off of it a ltitle bit.

My initial reaction is overt fert, which can lead to lockout of Mg, among others. Overfert is very tricky, becuase it locks out a lot of elements, that show up on the leaves... saying that merely adding epson salts will fix this is tenuous at best...

change res, PH to 5.5-6.0, use light fertilizer mix. What is the EC of your tap water? and PH of tap water? Are you using any medium? All these things will influence your PH which can also cause lockout of nutrients.

If you have access to General Hydroponics, it is the industry standard and baseline for all hydroponics here in the U.S. There are many many many people who can help you with GH products.


keep the faith, you'll get it

nuggluv if the temps in your reservoir are to low buy a fish tank heater and put it in it. I used to have to do that when I was in hydro.JMHO

Good luck
GCG

my thought is the root rot is preventing all nute uptake... do a thorough cleaning f your res, and start adding h2o2 to help clear up the rot. be sure to use enough to sanitize, but not enough to kill healthy roots! cu8t back on your ferts fo a week to let the plant recover and not help the rot along!

I would empty your reservoirs and replace with strait r/o water for one light cycle(12 hours at least) and then add your nutes at 1/4 strength in a five gallon bucket and check ph and consetricity(sp) of the dilution. This should flip your lockout problem if it is in fact that. Looks like mag and Potassium(K) defiency or lockout from here.

Hydro ph 5.8-6.1

Flood for 15 minutes every 4 hours while lights on and once for 15 minutes right in the middle of lights out. If using Ready Gro you can cut floods in half as far as time and frequency. If rocks, 15 minutes every 3-4 hours is plenty.

Super bloom can cook plants if your not carefull. It can load your media to toxic levels if not flushed regularly.

20 degree temp variance is no big deal but it will make most of your plants turn purple.

Red veins are usually mag def. in my setup and I don't really sweat it, i just adjust the mix a little.

What are ppm of your mix?

SM-90 for root rot

Tex

hey TK , i use sm-90 but didnt know it helped with root rot .
just curious what is does to aid in root rot ?

i use it for a wetting agent and also as a foliar spray for mite control

glad to know it does more than i thought !

EB