Yellow Veins in DWC

[Technical Stoner]

Hey guys, looks like I've hit a road block.
Done a lot of searching and still got really get a straight answer.

Some say P is low, some say N is low, some say the salts are too high, some say it is normal.... Who is right?

Basically the plants were doing fine in the DWC until about a week ago when a few nute problems started to appear.  It was yellowing veins in the leaves, this has now spread over 2 plants and I'm thinking they may need to bed pulled or will die.

Indoor/Outdoor: Indoor
Growing Medium: Clay balls
Growing Style: DWC
Watering/Feeding Frequency: DWC stuff
Nutrient Strength (PPM/EC): 1.8
PH Levels: 5.8
Temperature/Humidity Levels: 40% H    Water temp 23.3'C
Air Flow/Fans etc.: yes,
Lighting Type (CFL/HPS/MH etc.): HPS
Total Wattage: 400W
Growth Stage: 4 -5 th week flower
Plants Age: Autos so around 8 weeks total now if not 9
Cannabis Strain:  AK47

 

 

Nute break down

 

Diet Hydro DWC: 45 - 50L
Ec: 1.8
Ph: 5.8
Hydro Botanics Bloom A 100ml
Hydro Botanics Bloon B 100ml
Cannazym 100ml

 

 

Any help or insight would be great.
Thank you in advance

 

Regards

TS

 

[The Hash Nibbler]

Lockout causing Nitrogen deficiency. Check ya PH mate, something is dicky. I replied in your diary. Peace. Nibbler.

[buzzo]

Pythium is my Guess if it's DWC.

Nitrogen lock out should produce a more even yellowing not brown spots.

 

If not Pythium and you know your PH meter is in calibration i would tip in 0.5 ml per liter of Cal/Mag

Edited June 20, 2013 by buzzo

[Technical Stoner]

Aye nibs I seem

 

Well PH is perfect on a freshly calibrated meter at 5.8

It got a dick load worse since I started using the new nutes. I'm also due for harvest on the 8th.

[jaikai]

Lower your EC for a start...

 

Now for the long and possibly informative answer.

Check the roots are healthy, they still getting plenty of oxygen and no rot?

I generally call that a rust of sorts, find it in many a potting mix grow... now to find the cause.

May be due to a high EC...

Maybe root temps...

Maybe an additive you`ve just started using...

Maybe something else...

 

Between you, me & the wall, 99% of dramas are pH or EC related.

 

Whatever you do, please get all the basics squared away before throwing the Deficiency word around... it just encourages others to chime in with bullshit mate

 

All the best with it TS, you`ll nut it. If not, plenty ppl here to help ya get on track

 

JAIKAI

[Technical Stoner]

Lower your EC for a start...

 

Now for the long and possibly informative answer.

Check the roots are healthy, they still getting plenty of oxygen and no rot?

I generally call that a rust of sorts, find it in many a potting mix grow... now to find the cause.

May be due to a high EC...

Maybe root temps...

Maybe an additive you`ve just started using...

Maybe something else...

 

Between you, me & the wall, 99% of dramas are pH or EC related.

 

Whatever you do, please get all the basics squared away before throwing the Deficiency word around... it just encourages others to chime in with bullshit mate

 

All the best with it TS, you`ll nut it. If not, plenty ppl here to help ya get on track

 

JAIKAI

 

Well temp in the Res is sitting stable at 23.3'C

The DWC looks like a spa bath, there is a shit load of bubble / air

I'll do a root inspection tomorrow and get back to you.

I'll drop the EC on the weekend.

 

Regards

TS

[GreenGoat]

Can I just ask sorry in regards to the EC what you are using to obtain the 1.8 reading? is it based on mental maths or a digital reading?

[Chato]

Looks like macros are throwing out your micro's, happens a lot in dwc and is often fatal. Too much ammonium or phosphorus which leads to iron, cal, zinc and sometime boron issues. In your case looks like phosphorus levels went up without corresponding increase in iron and zinc. Varies from water source to water source but using trace element supplements when you change from veg to flower nutes should fix it although not this run. Good luck mate.

 

peace

c

[buzzo]

Is your Nutrient Solution in the dark.

Iron and Manganese ions oxidize and precipitate out of solution if U.V. light is present.

 

Are you changing the Solution regularly?, plants will hog certain Nutes and leave an imbalance.

Basically adding nutrient or water to keep the E.C. correct will cause deficiency's.

 

 

How often do you empty and change the Nutrient Solution?

This should be done once a week.

 

Jaikai's solution to lower the E.C. is oversimplifying the Answer, CHANGE the whole solution is what's really needed.

He is correct thou about the E.C. level. When the plants have filled out in bud size they require a lower E.C.

E.C.1.8 with your Auto's in the final stage is too much, should be more like 1.3 to 1.5.

 

Don't expect the plants to get Better all you can hope for at this late stage is to Stem the Tide

Edited June 21, 2013 by buzzo

[Naycha]

.............................................

 

Are you changing the Solution regularly?, plants will hog certain Nutes and leave an imbalance.

Basically adding nutrient or water to keep the E.C. correct will cause deficiency's.

 

 

How often do you empty and change the Nutrient Solution?

This should be done once a week.

 

.......................................................

 

 After doing a number of successful DWC grows with changing the nutrient solution only a few times I haven't found this to be the case. Granted if you are having problems it is wise to start with a fresh solution, but changing the whole solution regularly is not necessary for healthy and happy plants.

 

Naycha