Blotchy leaves in DWC can't figure it out after much research

Adikid

Member
so its a 27 site RDWC in a sealed room
Plants are 6 weeks old in Veg
Using Holland secret with same recipe i have been using for years on other setups. this is a first run on dwc in this room

Res gets changed out every sunday

-using 1000w HPS

-Temp 81-83 seems to spike to 86-88 at some point when lights off

-Co2 at 1200 ppm

-Humidity 45-50% and again spikes to 68% at some point

-Res temp. 65-66

-PH and PPM log for last 8 days... March 17 res change ph 5.6 900ppm, March 18 5.7 840 (adjusted ph to 5.6), march 19 5.6 830, march 20 5.5 800ppm (adjusted ph to 5.6), march 21 5.6 780, march 22 5.6 730, march 23 5.6 660, march 24 5.7 620.

Roots look great
nothing weird in res



any help would be really apreciated as i have to fix this before flowering them.

they have always done fine with my recipe so im stumped
 

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Adikid

Member
Ive never had to calmag. 4 years at this location using the city water.

leaves arent curling up at all. and ive only found 2 leaves in the entire garden with brown spots. Should i just foliar feed them with some epsom salt in case?

After some more research it really sounds like too much Mn (Manganese)

Manganese Toxicity
Toxicity:Chlorosis, or blotchy leaf tissue due to insufficient chlorophyll synthesis. Growth rate will slow and vigor will decline.

the damage on mine is really blotchy

thanks for showing me that page


 

Adikid

Member
i just thought of something...when i did my last res change my tri-meter was out of whack and had to use do lots of ph adjustment. i used lots of ph down to get it right. and if i remember correctly my ppm jumped 40 before it was where i wanted it. Could the ph up and down have locked things up? today is my res change day so im wondering if i should just do it as usual and see if the problem stops progressing?
 
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