What do you think is happening to my plants?

Hi All-

I am a first time grower having problems. I would love if you could help me assess what is wrong with my plants so I can fix it. Here’s some information about my setup.

Hydroponic DWC indoor grow with air stone and micro, bloom & grow nutrients switched out weekly.

Well ventilated with average temperature of 78°F. (1) 300w (168w actual) LED hydro galaxy grow light.

(3) OG Kush plants currently starting 4th week of flowering. PH checked regularly, and typically ran high at 7. I was using lemons to adjust PH, but PH would creep back up quickly after adjusting. I just switched water out tonight with nutes and adjusted PH to 5.8 using PH down (earth juice).

2 weeks ago I started seeing yellowing of the leaves, and it spread rapidly. I guessed it was a nitrogen deficiency due to the PH being too high. I pruned the yellow and dead leaves tonight and took a picture to help try and solve this.

I’ve included some photos of the plants when they were younger so you can see the progression. Any information on how I can fix this would be really appreciated… Thanks!











1 Like

Absolutely the pH at 7.0 was likely the problem. They look like they are doing pretty good right now.

Happy growing,

MacG

Here’s a response I got from ic mag forum:

I posted this question to two other forums, and I got about ten responses in total with possible issues ranging from: PH too high, PH fluctuations, too much PH down, feeding too much, feeding too little, poor nutrient brand choice, K deficiency, Needed CalMag, too small of a space, too high (or low) ppm, air pump too small to aerate roots, and Nutrient uptake at roots.

It was a little frustrating to get so many contrasting responses, but it prompted some research on my end, and I am inclined to agree with growaway’s response.

Here’s a little more info: My reservoir and air temps are both 77.9°F. I have always used 100% RO water. My roots do appear to be showing some signs of rootrot, although I can’t be sure that they aren’t just stained from nutrients… I have attached a couple pics of the roots. Do these look rotten?

I know in future grows, I will add additional air stones in the reservoir. Does Hydroguard do anything to prevent or cure root rot? Also is 78° too hot for the reservoir temp? How long should I “flush” the system, for a day? Or should I just keep running clean water through? Also should I clean out the reservoir?

Thanks all for the info! Any other advice you can provide would be helpful.


Yes, absolutely, you do have numerous problems going on. The pH and the reservoir temps would absolutely contribute to the problems that growaway and others mentioned, i.e. deficiencies or “lockouts”.

Obviously you are not having cold air or minimum temp problems causing the anthocyanins (red/purpleing) in your petioles (leaf stalk) and stems. And air temps are not above maximums, however, roots that can not function properly will cause all of the above mentioned symptoms, and it is a “root zone uptake issue”. In your case it is not low reservoir temps that are your problem, but high reservoir temps and a lack of dissolved oxygen in the water as a result.

At 78F you are at the maximum reservoir temp and absolutely you’d need a lot more air to keep the roots healthy at that temp. Ideal air temps are about 75-78F, but ideal reservoir temps are more like 68-70F, as much above 72F and it becomes very difficult to keep dissolved O2 levels high enough.

If you don’t have a way to control or lower your water temps, lowering the air temps a little could help, and certainly add a lot more aeration.

Hydroguard adds extra beneficial bacteria and other microbes that does help root zone heat tolerances, but it can only do so much on its own to keep the bad anaerobic bacteria at bay. All the roots should look like the bright white, probably hard and strong root, as opposed to the more mushy looking browner roots, those roots are indeed decaying and dying, or rotting.

As I said above, you will likely need to add a lot more air to your reservoir, and you will likely need to flush your reservoir completely more often to keep the reservoir clean during the grow, more often with complete reservoir “change-outs”/flushes. Look into root enzyme cleaners as well, something like hygrozyme.

Happy growing,

MacG