Rusty Spots on leaves

I might have found the Problem wich was cousing the Brown Spots. I had a Red/FarRed (660nm) light next to my LED grow light hanging, at the same Hight (35cm). After seeing this vid : www.youtube.com/watch I wanten to See of the red light coused the Problem and Shut it down the last 2 days. Now the Newer bigger leaves dont tend to Brown anymore. Lets See in the next few days is this realy was the case. But i will switch to Another nutriënt as wel to get my PH more stable. Thanks

Found this Text on the Site of hesi “In hydro systems with permanent standing water reservoir (such as expanded clay with water level indicator), we recommend the use of fertilizers for soil such as HESI TNT Complex and HESI Bloom Complex.” I Geus with this they speak about DWC ?

Problem is without a dairy there is no history or details concerning how feedings are done or what nuets are involved. We can guess it due to PH but without those kind of details that is all it is unfortunately.

@CRimp, the best thing you can do is get nutrients that run more stable. Adjusting the pH a lot can be pretty stressful on the plant. Sometimes just as bad as running it out of range. The roots don't like constant pH fluctuation. I can run mine for 10+ days and it holds the pH steady with the maxi nutrients

I have an adwa ec and ph pen. Will calibrate them and see what That does. Is it wise to correct the ph More often so ist Stays More stable ? Thanks !

This is definitely a pH issue. It is only affecting older leaves so I don't think you are ok at this point. Just make sure your you are calibrated if you are using a pH pen. I prefer the GHE test drops because they are 100% accurate every time. I use maxigro and maxibloom for nutrients. They hold pH stable better than most nutrients and they are cheap. Good luck!

would not worry about that its an old leaf they tend to get a bit of damage new growth looks good ec is a bit on the low side go up too 1.8 /2.0 she will start moving probably why those leaves are showing damage low ec.