Rust Spots/Burnt Leaf's/ Getting Worse

[SpliffTM]

How should i be applying the calmag and do i really need it?
I mean ive grown photo's in DWC for 5 - 6 years and never bought calmag once, i used GH 3 part flora series m/g/b always with no issues.
But im really new with auto's and i see some folk saying autos are crazy for gulping the calmag, So how much and when do others start to use calmag?
Thanks for all the feedback guys, its much appreciated

 

[davisgirl]

Did you change your lighting? LEDs are notorious for increasing calmag needs. Not sure about autos as opposed to photos. I’m a noob — so take what I say with a grain of salt. A lot of growers start a decreased dose of calmag in the first week. Usually by days 15-20 you can see the start of a deficiency if it’s there. Or that’s how I seemed to see it work.

 

[SpliffTM]

Same setup, usually 400w/600w m/h for veg and then 600w - 1200w hps for flower (depends what time of year) as in the loft

 

[rick-j]

Morning, i'm a total new guy with a few grows with LED lights, I've done a lot of bad things to my girls. Now that I have asked for help on this site, i'm slowly learning some tricks. Cal-mag was a big part for me--- but I had lots of other issues. Waira is helping me, some one with some real smarts will try and help you. Good Luck---------

 

[Waira]

one more thing Spliff', what exactly do you mean by "soft" tap water? I hope you mean naturlly low in ppm, and not treated soft water using ion exchange type system! Most of those use salt to strip the resin beads of the CaCO3 and "recharge" them,.. problem is, it's Na being released in the exchange when the minerals bind to the resin beads! Na is toxic at low levels,...

 

[Pro-T]

Looks like powdery mildew but hard to tell from photos. I wish you,luck.

 

[SpliffTM]

one more thing Spliff', what exactly do you mean by "soft" tap water? I hope you mean naturlly low in ppm, and not treated soft water using ion exchange type system! Most of those use salt to strip the resin beads of the CaCO3 and "recharge" them,.. problem is, it's Na being released in the exchange when the minerals bind to the resin beads! Na is toxic at low levels,...

Yes sorry low ppm,
I gave up and binned it, i didnt want to waste anymore time with it, the other 3 are going along nice, I also started 2 auto blue cheese from barneys .
Thanks for all the advice/help trying to help me, its much appreciated.

 

[AutoLowRyder]

24c - 27c RH 35% ish

the water temp in bucket is probably the issue, you havent stated what that is at the mo....... it need to be 20-22c minimum, as below that phos uptake is affected, temperature affects Ph, therefore nute uptake. You dont have a DWC res heater, to keep the temp up during lights out.......... the rad is not as good at this as a 1kw thermostatic heater fan, on a timer, for lights out etc........

if you have strong aeration, it can 'oxidize" nutrient before it has a chance to be taken up, so i usually up the Ec (Nute Only) to Ec1.2 plus you tap water Ec......(You dont state your nute Ec?)....do you use an Ec pen ??......... essential for DWC....... ensure when you top up your DWC the water temp is 2c above the bucket temp........... a cold shock will also throw deffs out..........

looking at the color they just look under fed, due to oxydation losses, the nute is lower than you think................. you do have aeration in the buckets right ??.............. a 25ltr DWC bucket requires 60ltr minute air going in, to keep the root sterile using an powerfull steralent = oxygen.......... try upping the nute Ec and the DWC res temps........... especially lights out.... ALR

 

[SpliffTM]

Thanks for the input, everything youve asked for ie water temp / ec etc has already been mentioned in previous posts.
(sorry its meant to be 21c - 27c) temps are all good it maxed out at 27c that dropped to 26c when i raised the light few inch,water temp is 18c - 20c raises to 21c from time to time , i try to keep it around that temp for the most D/O, and i have plenty of air going in, Usually i run 4 DWC buckets with the same pump.

 

[SpliffTM]

Ive also used the oil rad for around 5 years, my lights out temp is never cold enough to need a water heater. only thing i havent stated is my tap water is ph 7.2 and ec is .0 , yes i do have ph/ec pens