LED grow with DWC - Help needed leaves gone gold/yellow

[Johnboy101]

Hey guys,

I'm looking for some help with my grow. I'm doing a DWC grow with LED panels I'm running air at 26c. I've been using the same nutes as before 10-5-4. I have 2x300w LED panels which due to the problems with the leaves changing colour I have moved to about 3ft high. I have also tried turning one of the panels off to see if this helps the plant recover. The water is reading 5.9ph and about 800ppm.

The leaves start to change colour on the older fan leaves first and are random all over. There is no obvious starting from the top/bottom first. The plant seems to of stunted in growth and development is very slow. Much slower than I have ever had before.

I took some of the leaves off so that I can take a good picture for anyone to take a look at and give some advise.

Many thanks for anyone that can help in advance

 

[Rifleman]

How are you measuring your ph?

Also what do you mean running air at 26c? Is that the temps of the grow area? Nutrient solution temp?

 

[Johnboy101]

Hey, using a ph pen. Also calibrated it myself with ph up and down.

Cheers

 

[Amadeus Forzin]

High johnboy and welcome to

I'm a soil guy, not hydro but I do use led lighting. I doubt that the lights are your problem. It looks like nute burn to me or maybe a zinc def. There is a picture guide in my sig, have a read.

 

[Rifleman]

You should calibrate the pen with a calibration solution of 7.0 and check/recal every couple of weeks. I've had one go bad on me and nearly ruined a grow before I figured it out. I'd start there and check the calibration of the pen. If it's good then we have to look else where.

 

[Johnboy101]

Big thanks to everyone for the advice. I have ordered some more PH 7 buffer to check my pen again. Might even buy another pen to double check. Will keep you all upto date when I get the stuff to check, will have to wait a couple of days for delivery though.

Once again big thanks to everyone.
John

 

[Johnboy101]

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[Johnboy101]

Hey

Just a quick update on my plants issues . I've got my PH7 bufferand checked my pen. The poem came in at 7.1 so I guess that the pen was right in the first place. The bottom tank was sitting at 5.9. I guess the only conclusion is that the plant has suffered nutrient burn.

I've emptied the bottom tank now and filled with clean water and set the PH to 5.8. I will keep an eye over things during the next week and let you all know how it goes.

Cheers John

 

[Rifleman]

Were you running your nutrients hot? What ppm do you run?

 

[Johnboy101]

The ppm was running 800's then I put in a water pump as I didn't originally plan for one. After this I checked again and the ppm was 1100! So I think it's lesson learnt that without the water being pumped around constantly there must of been hot spots of nuts in the water. Can't believe it now I think about it, just thought the two air stones would of agitated the water enough.

Hopefully I'm on the right path now.

Cheers John

 

[Rifleman]

When your water level falls your nutrient within that water becomes more concentrated. With less free water to consume your plants must consume more nutrients than they need. I don't have the verbal prowess to explain it better, hope you understand better than I explain.

 

[Johnboy101]

Lol. ..is cool I get what your saying. I'll just turn the tap off from the top feed and add clean water in manually for a few days. Hopefully that will reduce the nutrients for a while to allow the plant to make a good recovery.

Thanks for the insight
Cheers John