Help with Diagnosing (Photos included)

Running run to waste hydro in Grodan rock wool using GH nutes keeping ph of water between 5.7-6ph and nutrients are around 400ppm using lucas formula for 200ppm and CaMg for other half. Feeding 1-2 times per day depending on how light the blocks get. Waste is coming out around 200ppm and 7.8ph (not 100% sure if I am driving myself crazy with the ph runoff or not) all in vegetative state. Running 1000watt MH heat and airflow are not a problem and I use my hand to measure distance from plants by where it gets hotter. Having issues with spotting (never foliar feed with lights on and foliar once per 2 weeks) curling/wrinkling leaves and yellowing in spots all over the plant not all leaves but from top to bottom there are scattered leaves with one or more of these defects. Any and all input would be much appreciated, thank you for your time! Also first time using lucas formula feel free to critique me on anything! Much love everyone!
 

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Atomizer

Well-Known Member
The uptake of large quantities of nitrate-N (NO3) in veg will drive the root zone ph up. Be careful of using phosphoric acid to control ph with lucas formula which has P in spades already. Excessive P in the rootzone causes calcium, magnesium, iron, zinc and copper to be locked out. If thats already the case, then switching to a different acid such as sulphuric or nitric will add less antagonistic elements, (S and N) which the plants will use in veg, unlike the P.
 
I highly appreciate the info! This could very possibly be the answer I was looking for! Ill be going to my local hydro store to get a new ph down! As far as the first part of the answer goes, if it is up taking large quantities of nitrate-n (NO3) in veg driving the ph up in root zone, would that be considered a good thing? and maybe im just seeing these results due to the high amounts of P that I am putting into them? Sorry to be a bother just want to make sure I fully understand. Thank you again for any and all input!
 

Atomizer

Well-Known Member
Its not a bad thing, understanding what elements do what, can be helpful when diagnosing potential issues. In hydro nutes, the main source of N is nitrate (NO3) from the calcium nitrate, the other source is ammonium (NH4) which typically accounts for 10-15% of the total N. Uptake of NH4 lowers the ph, NO3 raises it. Calcium nitrate is the cheapest option for providing Ca, NO3 and depending on the brand NH4 too.
 
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