not new but stuck

Hi everyone. I have been growing for some time and have just came up with a problem I cant solve. I have a few Brainstorm from dutch passion and a white widow from g-13 seedlings and some cuttings in a 10gallon DWC bubbler with air stone and a pump to a sprinkler head that delivers oxygenated water with advanced nutrients at a rate of 500 ppm. my ph is from 5.5-6.5 temps are 77 and humidity is 40%. I know that is a bit low for humidity but I dont think thats whats causing the problems you can see in the pics. The first set of true leafs are not doing well at all. With yellowing and now brown spotting. I cant nail whats wrong and dont have many of these seeds left so I dont want them to die. The cuttings of from my purple lady and kelara gold are not doing much better but they were a few weeks into flowering when I took them so it will take time for them to re veg. Any help would be great thanks in advance.

looks like ph and over nute issues. you say your ph is 5.5 to 6.5? it should only be at one level. 5.8 works for me! say, does that sprayer work 24/7 or is it on a timer? you may be over watering as well.

its on 24/7 but with an air stone the water has so much oxygen my understanding is you cant over water them. My other DWC has a huge mat of roots just floating in the water. The ph can drift so I try to keep it at 5.6 ish but like I said it drifts a bit someties. I thought about over feeding but its not the tips burnt but rather the middle of the leaf. Would over feeding do that?

try this ! time your sprinkler for once an hour for 10 minutes. there are bubbles from the airstone already hitting the netpots. let it do that for a couple of days and see what happens. i've done what you doing before and failed. are you using rockwool?

yes im using rockwool and clay pellets. the pots are very far from the water and the roots are just starting to show. I dont want to fill it up till it hits the post as that will take a lot of ferts. thats why I got the sprinkler head.

Looks to me like ph flucation

Try keepin it 5.8 - 5.9 constantly

Also, dont keep that pump on 24/7, u need to get some kind of timer on that thing sinse tech this is a modified cocco aero setup. Ur plants do look slightly over watered due to 24/7 operation. They need some alone time with the air

JMO

Whatever your problem was - as described in your previous answers, it seems to be fine now. Your new growth looks good, so whatever you are doing now - keep doing it.
Those couple of brownish leaves will be of little to no harm, now that you are getting healthy new growth.

thanks for all the help guys. Im going to get a digi timer today for the pump. 10min on per hour? is that the preferred timing?