Plants drooping in RDWC

[Boradan]

Having an issue with my plants at the minute.
3 out of the 4 are drooping a lot.

Strains:

• Dinamed CBD Auto
• Seedstockers Northern Lights
• Mephisto 4 Assed Monkey
• Sweet Seeds Dark Devil

RDWC system (Tap water approx 210 ppm as base)
MegaCrop
Remo Magnifical
Great White
Atamai Ata Clean

Air temp: 21-24C
Humidity: 40-55%
Water Temp: 18-19.8C

I had pH issues last week due to my crappy Fleabay pH pen crapping out on me.
I received my Bluelab pH pen and EC meter last friday and discovered that the ppm meter I was using was also WAY off the Bluelab reading.
What I THOUGHT was a pH of 5.8 turned out to actually be 6.5 once I had set up the Bluelab.

What I have done so far:
Once I was able to correctly measure pH, I changed the rez and set it to pH 5.9
Due to 3 of the 4 plants being Dark and clawing, I reduced the Feed amount.
EC continued to rise after this, so I took out some of the rez and replaced it with pH'ed tap water as this also pointed to over feeding (that was only this morning, so no feedback on that yet).
I have taken the Airstones out and given them a thorough scrubbing in case it was lack of DO in the water.

The roots all seem nice and healthy

 

[STILLSMOKIN]

I believe its a toxicity and ph issue in pics. Also i add my water in res then ph all together. Also i run ph of 5.8 to 7. Plant will take in all nutes correctly if it let it swing. Also as plant takes up water and ec swings high then ph will go too low and it will lockout. So always run a very low dose of nutes to start then watch plant everyday for signs in leaves. If i were you i would dump res do full strength MC only. Ph to 6.5 then check daily to see what the girls need. This is my first time using dwc and MC but my thoughts are defiency is easier to handle than excess. Also if running led add full strength calmag. Make sure its derived from magnesium nitrate and not sulfate. Sulfur based nutes get sucked up fast and can be toxic.

 

[Boradan]

After flushing and reducing the amount of nutrients and using 5.8pH I am getting some signs of improvement:

Dark Devil a few days ago:

Dark Devil today:

The other 3 plants are also showing signs of improvement, but 2 of them look as if they need the nutrients reduced a touch more.
Will keep updated...

 

[STILLSMOKIN]

Looking good!

 

[Boradan]

Looking good!

The Northern Lights is also improved, but the 4AM and CBD Auto are still having issues.

Seedstockers Northern Lights:

Mephisto 4AM:

Dinamed CBD Auto:

Both the CBD and 4AM are showing some signs of recovery, but not as much as the other 2.

 

[STILLSMOKIN]

I would really let ph get up a little more. Mg and cal almost lockout at 5.8. I let mine swing from 6-7 all the time and doesnt hurt. I dont think i will let them see 5.8 after seeing a chart on lockout with ph. Mine was showing the same in dirt that was to low of ph

 

[Boradan]

I would really let ph get up a little more. Mg and cal almost lockout at 5.8. I let mine swing from 6-7 all the time and doesnt hurt. I dont think i will let them see 5.8 after seeing a chart on lockout with ph. Mine was showing the same in dirt that was to low of ph

The issue happened when my pH was too high though (6.5 as it turns out).
This chart would seem to indicate 5.8/5.9 for optimal pH:

I am not stressing about +/- 0.2 pH though. As long as it stays over 5.8 and below 6.2, then I won't be adjusting

 

[Boradan]

alternative chart:

 

[Waira]

... Borodan, part of this is the differences between strains, what they tolerate, prefer, sensitivities,.... you have a single "menu", and sometimes this doesn't make all the customers happy! .... 4AM and CBD are showing some minor N toxicity I believe,...sharp clawing at the tips....
Keep that pH stable in the proper range, which is rather limited as you see,... small deviation in hydro can make large differences in certain nutrient's availability... Good news is that I don't see any other significant symptoms!

 

[Boradan]

View attachment 909105 ... Borodan, part of this is the differences between strains, what they tolerate, prefer, sensitivities,.... you have a single "menu", and sometimes this doesn't make all the customers happy! .... 4AM and CBD are showing some minor N toxicity I believe,...sharp clawing at the tips....
Keep that pH stable in the proper range, which is rather limited as you see,... small deviation in hydro can make large differences in certain nutrient's availability... Good news is that I don't see any other significant symptoms!

Pretty much my own thinking so far.
The purchase of the Bluelab pH and EC pens has definitely assisted as both my old (fleabay) ones were wildly inaccurate.