Still having problems with one of my girls -- yellow / brown spots on leaves!!! HELP!

Ok, so I have 3 girls, 1 auto ak47/lowryder, 2 fem haze/kush.

Runnin DWC's on 2 and soil on the auto.
I'm using what the directions say on the dynagrow grow nutes (about 1.5 to 2 tbs per gallon), about 750tds, temps run around 78-84 and RH is 50-60. Oscilating fan. I'm about to switch to bloom but i want to try to figure out why I keep getting yellow spots on 1 of them.

I check PH every other day and it's always around 6 even, maybe 6.5 at peak, piss yellow. I thought it was nute burn, so i let the nutes drop to 150tds, didn't help. boosted them to 900, didn't help, dropped down to 750, don't see a difference. You think it's cal/mag?

To be quite honest, I don't care TOO much about it cuz it's only affecting 1 of them, and it's only on about 15-20% of the leaves. Only thing I don't want to happen if I let it go untreated is a drastic affect on my yield or something worse (hermie / male).

Any help would be great! I can take more pics if needed.

I think I had this problem before. Didn't effect much I dont think. It was an isolated incident that didn't spread just showed up on a few leaves and that was that. It might be Mg deficiency. Mg is adsorbed better at phs a bit higher so maybe u just dipped a little low. It wont go away but as long as it doesn't continue to show up on new leaves ur fine. I would just stay the course.

You are running a deep water culture system with PH levels between 6.0 and 6.5? DWC system have to be pretty muchs tits on when it comes to PPM and PH and such. And things happen really fast when they go out of wack. Maybe i miss understood you, But I would get that PH down to 5.8 on the DWC and never allow it above 6.0 even in fluctuations.

On the affected plant what do the roots look like.

So you think my PH might be a little high for them? One of the DWC's (although a different strain) is healthy as shit, no problems at all. The other has these yellow / brown spots. I'll try lowing the PH on the one and see if it helps.

The roots are extremely healthy imo, then again i'm not too experienced with this, but they look good to me (see pic blow). This plants roots look better than the plant without problems, strange. They don't feel slimy or anything.

I read somewhere else plants like 800-3000 TDS, I'm keeping them around 800 now. Should I boost that or is it ok?

I dont have a thermometer to test the temps in the rez, but it seems cool when I touch it. I've read it should stay in the mid 70's. I would guess it's around there.

It may have been an isolated incident since the newer leaves look good (in the second pic), but you can see one leaf with a little scorching look on the edges starting, so I feel like the problem is still going on, it just takes a little to set in on newer leaves.




First Plant (healthy):


Second (one with spots):


Third (auto), 43 days in.


Group Picture!:


In this one, you can see my setup basically. I have 1x200watt 6500k CFL, and 1x150watt HPS. HPS isn't on during the time of these pictures so I wouldn't blind myself.

Sometimes growing different stains in the same hydro system can be very difficult. I have grown Nirvanna Ice, which loves to drink down large amounts of nutrients, while right beside it I had another strain that freaked out when I just showed them the bottles of nutrients. Mid 70's for your rez is to warm. 6.0-6.5 PH is also way to high. Shoot for 5.6-5.8 PH

Alright -- the PH is easy. What are the safe ways of lowering the rez temp? I don't really want to get into more equipment (coolers and all). Is there an easier way? Or if cooling equipment is cheap and easy enough to manage, what's good? Do you think warmer water in rez and ph a little high could cause the problems shes having, or does it appear to be something with nutes?

Like I said above, you need to have the growing conditions right on the numbers, or the plants will fry in a system like yours. Take a few 2 liter pop bottles 3/4 the way full of water and freeze them. Place one of the frozen bottles in the rez about ever 8 hours or so. what ever it takes to get those temps down to about 65 degrees, then get the PH down to about 5.6-5.8. And do not trust those dam PH drops or strips. they are not accurate enough for your needs.

Google: Sper Scientific, they make a high quality PH pen. Model #850051 is the one I own. It has a built in temp gauge so it takes that into consideration for a more accurate PH. For only $38 this is about the best PEN I have ever had. Even beats the $85 pens I have had before.

Side Note: Not sure if you answered this. But you have asked about cal/mag. If you are running tap water, you would not need to add Cal/Mag. Not trying to make an argument here, but in my opinion, in most of America, running R/O water is just a big dam waste of both water and money.

Nice, i'll check that pen out. I hate the drops, pretty annoying and hard to pin point your ph. I'm running city water, so yeah, definately wasn't going to waste my time buying other water. Alright I'll try to get my ph lower and get some frozen bottles in there, thanks for the help man much appreciated.

Oh, one last thing. Do not allow the roots to come into contact for very long with the frozen bottle. Do what you have to, so this does not happen. Stuff it in the corner and put something in front of it if you have to.

Lord Dangly Bits said:

You are running a deep water culture system with PH levels between 6.0 and 6.5? DWC system have to be pretty muchs tits on when it comes to PPM and PH and such. And things happen really fast when they go out of wack. Maybe i miss understood you, But I would get that PH down to 5.8 on the DWC and never allow it above 6.0 even in fluctuations.

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Agreed. MJ don't like major changes below, so try and keep things stable. PH should be 5.8-5.9 (you can go out of these ranges but it's not ideal) and a gradual increase/decrease on EC/PPM.

At PH 6.0-6.5 you locking out Mn & Ca which could be causing your spotting together with fluctuations. Also try and change your PH by no more than 0.5 per day (not entirely necessary, but helps). Hope it helps.

Lord Dangly Bits said:

Oh, one last thing. Do not allow the roots to come into contact for very long with the frozen bottle. Do what you have to, so this does not happen. Stuff it in the corner and put something in front of it if you have to.

Click to expand...

Thanks! That definately helps alot. I'm waiting for the ph pen you recommended to arrive (bought it online from ebay that same night). I also just finished hooking up ventilation system (AC intake, heat exhaust), flushed both girls, changed rez's and adjusted ph down closer towards the upper 5's from low 6's. I also bought a 2700k 200awtt CFL to replace the current 6500k bulb in there for flower.

I'm keeping my lights off 24 hours, then turning on 12/12. Do those water bottles (when frozen or not) sink generally? Or will they float? Maybe I could string up some fishing weights to them to keep them on the bottom? Or will metal weights in my rez not be good (assuming I need to weight them down, i dunno if they float or not).

Thanks again for ur help bro. hopefully both come out female and stay healthy.

Both Ice and Air floats in water. So yes it will wants to float. Do not use lead to submerge it. Maybe find a piece of granite or some other dense rock and tie it down. The bottle does not need to be totally under the eater. But the more the better.