Help

In a dwc seeds are ecsd Using technofloras good to grow for nutes. 400 w mh 80 degree room temp 67 degree res. good airflow ph is at 5.8.... Started noting some dark spot on my seedlings that are in there second week of veg. The dark spot started in the lower leaves and and in the middle of the leaves then they started to turn yellow and brown spots and curl slightly upwards. roots look good and plant is growing new roots and leaves pretty consistently I also noticed purple branches on these particular plant.... Any suggestions ?? I added quarter strength magical a few days ago and it didn't seem to slow down. Not sure if I'm targeting the right deficiency.

notorius rust spots try to spay one teaspoon baking soda to one letter water.. and check roots change water every five days.. fresh air is always good, what kind of bublers do you have??? stones try to use air stones with micro spores the smaller the better to bad you cant take disolved oxegen reading from your water i get this sometimes i still havent been able to find out whats causing it, its always from young but these are the precautions i take and they come right out of it??

Was at half strength. Then a few days ago when I realized It was a deficiency and not root burn I upped the ppm from half strength to almost full. I do change the water weekly and I decides to flush now and make a new solution. How many hours should I flush??? If needed at all

While it's flushing I plan to make my new solution in a separate container...should I go full strength ???

And I don't think it's anything I spilled because I have 3 out of six plants affected the same exact was from the bottom leaves

How do the roots look? Pic helps

They're white and multiplying daily

Using ro water? Tried calmag?

Just flushed my system added a new solution in ro water. Ppm is 1000. 1100 is what techno flora recommends. There are four air stones the thick grey ones in 12 gallon res, is that enough? The good to grow comes with magical. Is that the same as calmag??? I'm a noob I know. this is my first dwc. I'm Hoping this problem doesn't progress.

And i put the magical in.

That's too high ppm. You gotta slowly increase that shit and cap out at 1000 or so. Some strains less!

Ok so I dumped half the res and added new water my ppm is at 500 . I didn't know I have to do that every res change. I figured i only had to do this the first time I introduced nutes.... So does anyone know what the deficiency is ???