yellow leaves

[GoonerBud]

Hi.
First post and require some help identifying the problem with my leaves.DWC grow in 4th week of flower under 600W HPS using GH trio nutrients. Roots looking good . PH tends to keep dropping back to below 5.5
Anyone out there able to help.
Thanks

[GoonerBud]

Forgot to add also using Hydroguard and CalMag.
Could it be Calcium or Magnesium deficiency and I need to up the Cal Mag dose?

[JeffInCanada]

Forgot to add also using Hydroguard and CalMag.
Could it be Calcium or Magnesium deficiency and I need to up the Cal Mag dose?

Hi GoonerBud
Looks to me like the PH is too low for both Calcium and Magnesium. I think you need to up the PH. Have a read of this link for Calcium. You can find the Magnesium page as well. I would concentrate on the PH, not adding more CalMag.

https://www.growweedeasy.com/cannabis-plant-problems/calcium-deficiency

I am not a hydro grower but I know that PH can be tuff to maintain properly. I think other nutrients do require a PH around 5.5 but not Cal and Mag so it can be frustrating and confusion to get it right for all.
You're still going to get some good smoke I bet. Good luck!

[dilvish]

If you are growing in soil then 5.5 is too low for the PH. With the GH trio make sure you PH the water AFTER you add the nutes.. soil should be between 6.0 and 7.0...6.5 if you can.

[Rwise]

Its right there in your post "PH tends to keep dropping back to below 5.5", fix this.

[SoOrbudgal]

He's DWC needs 6.0

[GoonerBud]

Hi everybody who has replied. I appreciate your help. A pH problem seems to be the overall opinion.
However what I need to know is what could be repeatedly bringing the pH down to 5.0 so quickly after I correct it back to 6.0 with pH+ ???

[Rwise]

I dont grow with DWC, but it is my understanding of it that the PH drops and must be checked daily.