I have 5 white widow autoflower plasts about 3 weeks from germination. 4 of the 5 look great, they are in 3 inch peat pots in my 2’ x 4’ grow tent. Randomly one of my plants has developed these dark brown spots. I am wondering if this is light burn or if this looks like a disease. The other 4 plants look great. Lights are about 2 ft away from the plants and I make sure I don’t get water on the leaves. Not sure why just this one plant decided to develop brown spots. Any help appreciated thanks dudes and dudettes!
Here’s my setup:
2ft x 4 ft grow tent
Have fresh air intake fan cycling every 5 min
Small Air circulation fan and lights running simultaneously for 18 hrs.
Bloom plus xp2500 led light.
Foxfarm happy frog soil
I have a grow tent controller that I designed myself that maintains soil temp and ambient temp at 70 deg F, RH stays about 35-40% I am able to graph it and it stays pretty consistent so I don’t think temp or RH is an issue. No bugs in the tent that I can see.
Hey thanks for that chart, that is valuable information I could use for the next iteration of my grow tent controller.
I know my RH is a little low but don’t have any way of increasing it at the moment other than turning off fans. Ambient RH is about 30-40 outside my tent.
To answer your question I don’t know the PH, I need to aquire the tools I need to be able to measure that. I’ve just been reading the awesome documents sent to me after buying my first batch of seeds, and it’s been a lot of information all at once, so I’m slowly taking it in and adapting.
Oh I hear you completely! It’s easy to get overwhelmed with the abundance of information on here. Best way I was able to control humidity was getting a humidifier and controller, however a cheapo way of doing it is a bowl or bucket of water with a soaked rag hanging off the side, it’ll raise the rh a few %
As for the ph that is going to be something you’ll want to address sooner rather than later as proper nutrient uptake is key to their survival at this stage, many forum members on here as well as myself will recommend the Apera ph20 meter, its what I would consider the upper-mid grade ph meter and is on Amazon, it is very accurate compared to the cheaper $10 ones and gives me peace of mind.
Thanks for the feedback I’ll surely get one of those pH meters ASAP, and I’ll take your advice on raising the RH. I know soil pH is important and I’ll report back once I get a reading.
Can you recommend some products to raise or lower the pH if mine is off?
Welcome to your new happy place . The apera is what i have also. you ph water going in and out. No nutrients are needed for 4 to 5 weeks when using FF. PH up and down also available on Amazon. I would put the bucket and towel in tent as @ThatsNotMineOfficer said. Give the plant a bit of time and see what she looks like in couple days. The light you have is 250w. You have a lot of plants in your tent. Have fun and good luck
Yes any ph up/down is fine you don’t need a particular brand, To find your soils ph a slurry test is good as stated above. The water going into your soil is what’s important with the FF soil it’s most likely fine till like mentioned before a handful of weeks into veg.
That looks like some next level stuff you have there . Once you get the green thumb it’s a very fun hobby! I’ll stick to my hot peppers tomatoes and basil for now lol. Makes for some bangin’ home made pizzas. Which I will need when harvest comes.
@bananasushi you are funny. I just envisioned my husband looking for my homemade pizza sauce after a trip to the garage for a smoke and asking how long it would take me to make pizza dough from scratch…yes that really happened once.
Until u get a meter u can use distilled water from the store Amazon has the apera ph20 for about 50 bucks. If u have the cash get the photo I believe it is. It does ppm and pH and a couple other things I believe like 5 in 1 deal but we’ll worth it. Make sure u get the apera storing solution also for it. Has to be the apera kind. Other off brands ruin the probes on the meters
Im having the same problem with my plants. I was told I have a potasium deficiency. I fed the plants 4-5 days ago and today Im give them cal-mag. It should fix the problem
Solid advice from @ThatsNotMineOfficer. Proper PH is very critical for nutrient uptake and too low or high can prevent some of the main and secondary nutrients from being absorbed by the plants root system
Thats what I thinking but them it started to spreading around the bigger leaves. Im on FFHF. They are 43 days today from sprout. I fed them for the first time 4 days ago. I think they were hungry. Not sure. Let see if in the next few days they get better. Im watering them right now. Will upload photos to my journal and will tag you so you can see how they are doing. First grower here lol
Good deal, I tried to zoom in and check the affected leaves for a possible deficiency. Good thing is you can’t OD on calmag so keep that going with every feeding especially transitioning to flower. Make sure on feed/water days that you give enough for 10-20% run off. This will help with flushing the unused salts and minerals from collecting in your root zone potentially locking out nutrient uptake
. The apera is what i have also. you ph water going in and out. No nutrients are needed for 4 to 5 weeks when using FF. PH up and down also available on Amazon. I would put the bucket and towel in tent as 
