DWC veg from seed: Rust Fungas, CalMag def?

[cogreen]

Hi all,
I'm a first time grower and am having some leaf discolouration which has been getting worse over the past week.

I initially thought the issue was calmag related, but I'm supplementing with calmag plus. After some investigation I'm wondering if the issue could be "rust fungas"...

Any help here is very much appreciated.


Grow method: DWC Hydro.
Res: Each res has 5 gal of filtered, PH'd water with nutes. PH is 5.8 - 6.1. Res temps @ 65F always.
Strains: One res has 2 "Super Sour Alien" and the other has 2 "Hurricane"; all of the Reserva Privada line in CO. The plants are in veg and are about 3.5 weeks from seed.
Nutes: Using the full Fox Farms (hydro) line up. Supplementing with CalMag Plus and Hydroguard.
Lighting: 8 x 2' T5 veg bulbs. Currently on 20-4 lighting schedule.
Ventilation: 4 x 171 CMF 140mm fans. 2 intakes on bottom and exhaust on top. Multiple small fans inside cab for circulation. RH is between 35 - 60%. I have a small humidifer in the cab, but it goes off with lights out.
Cabinet: DIY... W x D x H: 39" x 29" x 48"... 7.85 ft of floor space and about 31 cubic feet of airspace.


These rust stains started one one plant (one of the SSAs) and have progressively spread. As shown in the pics the SSA are worst affected right now, but I see it starting on the Hurricane.

On Sunday I did a 30hr flush of PHd water + 2 drops of "Sledge Hammer Flush" and re-nuted.... More details in my journal in signature.

Thanks in advance

 

[DukeO]

From what I have read about rust fungus it said that most times it will show on both old and new growth.

I am only seeing old growth with the issue right now. I have never had it. But having high RH is said to be another factor in getting it.

(I have a small humidifer in the cab) That may have something to do with it if it is rust fungus.

If that is what it is and not a calmag issue from a lock out. Which would of been my first guess.

I would cut off those lower leaves one way or the other and keep a close eye on the new growth to see if your flush did the trick.

If it starts to spread to new growth. Then you may need to use a fungicide or to even start over if you can not control it.

I have not used any. So can not recommend anything.

Hopefully your flush will work or if you do have rust fungus someone else who has gone through it will stop by.

Good Luck!

Hope it was just a lock out...

 

[cogreen]

DukeO -- thanks for chiming in and the incite!

I was inspecting the leaves with a 100x scope last night and I don't see anything "above the leaf surface". Based on what I was reading about rust fungus I think I'd see some "spores" or "raised" areas of the leaf which indicate fungus; I didn't. The discolouration appears to be "ingrained" in the plant leaves.

I'm beginning to wonder if it's a lockout issue as you mentioned.

Plan to hit the hydro shop today to get some additional advice.


Thanks again!

 

[zakey]

I've had this problem before and it's always been down to high ph or dramatic ph swings
I'd recommend keeping a close eye on your ph