RDWC Nutrient Problem! Leaves with Spots! Help please!

[RandomtasK]

SPECS -------
18 site RDWC
6000w
Cultured Solution Nutrients
Currently 410PPM
PH Currently 6.1
Strains: GDP, Triple OG (is this even a strain?), Cherry Pie
Ambient Temperature: 69 F
Water Temperature: 70 F
Relative Humidity: 50%


I am seeing rust colored spots and some yellowing on my leaves!I am new to this RDWC and having come from growing in coco this is definitely a different world. we're about week 5 of vegging from clones. all of these strains are adapting to the system differently. The large bushy ones are the GDP, the thinner lankier ones are the Triple OG and Cherry Pie, The Cherry Pie exhibiting the worst signs of rust spots and yellowing. I was feeding them very lightly for the first 2-3 weeks due to lack of a TDS meter and lack of RO water. once we got that sorted out we started feeding them according to the Cultured solutions feed schedule. My problem is i can't tell whether this is a burn or a deficiency. we added Cal/Mg at 3 mL/gal 24 hours ago. any insight is much appreciated, thanks in advance!

 

[Dusty Kiefers]

Hello there noticed nobody has posted yet so i'll give a novice opinion. The first photo looks like cal deficiency, but some kinda look burnt. I would think if your p.h. is droping rapidly your feeding to much. If it is raising your not feeding enough. Hope this helps as I am rather new to dwc also. Peace and godbless.

 

[SnaFu]

How are the roots looking? Could be an uptake problem. Have you looked into beneficial microbes or are you running a sterile rez? Either are options we use in dwc to fight pathogens in the water that create a slime on the roots and suffocate them, leading to problems like pythium and root rot.

If you're sure everything in your system is dialed, and your ph steadily rises then this is what you have. Good news is, it's easy to fix if that's the case!

 

[Bassman59]

Agree with above posters. Make sure ph is correct. If so probably going to need to add some cal-mag to your mix. Make sure ph is right before making adding anything. If ph is off and you add it wont fix it and once ph is correct you'll have too much cal-mag. Calcium best uptake range is going to be in the 5.4-5.8 range for hydro too.

Snafu mentioned beneficial microbes. I am totally sold on Fox Farm's Bush Doctor Microbe Brew. I add 5ml @ gal from veg through week 1 of flower. Took the place of AN Voodoo Juice for me at a fraction of the cost.

 

[lendee]

Hi I agree with some sort of tea or bennies I use Orca very good. Also what is your water temp running nothing will help if it's too high the other thing is to check on the amount of DO dispersed oxygen in the system. I was looking very similar and found DO as my problem increased my air pump from 500 to 1150 gal/hr and all was good. Funny I had sour diesel and catatonic running together and only had problems with the sour diesel, The catatonic was flourishing. Please bring us up to date on your problem.