Need some advice from any experienced growers

[packetjunkie]

Hello guys and gals! I am new to this forum (I actually just created an account to ask for help) and I am a pretty new grower also. I started growing about a year ago; since then I've done 3 auto-flowering plants, one at a time, with decent success, however the plant I'm seeking help on is my first photo-period grow. As a said I'm new so please bear with me I will try to make this as short and concise as possible.

Strain - "Purple Afghan Feminized" seeds from MSNL
Environment - a small grow tent with a 4" carbon filter and fan (I think the tent is ~2x2x4)
Medium - ~50/50 mix of Fox Farms brand Ocean Forest soil and Roots Organic brand soil in a 5 gallon fabric pot
Light - ViparSpectre brand 450w LED light
Water - I just use tapwater, pH it to ~6.5 using a pH meter (It usually takes 3 drops of pH down for plain water), and let it sit open for a few days before I use it. I water about every 4 days or when I stick my finger all the way in and it feels dry. I water until 10% runoff.

Veg time for this plant was ~6 weeks. At around 4 weeks I tried to fim it, fucked that up so I decided to just top it, and ended up topping it too far down the plant (I cut a good bit off ~2 or 3 "nodes" i guess); after this I just let it grow and continued to LST it the best I could and started flowering at ~6 weeks. As of typing this it has been in flower for 25 days, or almost 5 weeks. The plant is very packed with growth so the leaves that weren't getting much light started dying which I thought nothing of, however I watered it yesterday and noticed more yellowing leaves (That is the 1st couple pictures) and today I checked and even leaves that are getting light are turning yellow and brown(These are the pictures in the tent). I have tried to do some research but as I'm sure you know it's hard to tell who's full of shit and who's not and have seen everything from it's completely normal to it's nutrient deficient and everything in between. As I said this plant has only had plain water no nutrients but I do have some nutrients and Cal-Mag that I used on previous autoflower plants with negative results so I decided to try just plain water on this one and it seemed to be working until now. Any advice would be greatly appreciated, thanks for your time!

 

[AngryBird]

Hi there and welcome to the best place to be. I have a link in my signature about problems.
It looks like a nutrition problem. In your case too little of it.
What is your day/night hours?
If you have a lot of day your plants need some juice to bud up.
There are some nice buds there.
Have you checked for pests too?

 

[Weaselcracker]

Yeah I’d guess it’s starting to finish up what nutrients it had in the soil, and depleting the older leaves to find what it needs. Which is fairly normal in flowering anyway. I’m not a soil grower myself but you’re probably at the point where you need to add a little something.
I’d also say that your plants look very good and having some older/light deprived leaves die off is totally normal. There are lots of soil growers who can help you with what to add now.

 

[packetjunkie]

Thanks AngryBird and Weaselcracker. AngryBird, the hours are just 6AM-6PM light, 6PM-6AM dark set on a timer. I did inspect the plants and under the leaves with a flashlight I can't see any pests.
I do have Cal-Mag and Fox Farms Grow Big, Tiger Bloom, and Big Bloom. I have used the Cal-Mag before and it was fine but every time I used the nutrients it seemed to burn the tips so I'm not sure which one to use and how much. Again, thanks guys!

 

[philthegeek]

"I have used the Cal-Mag before and it was fine but every time I used the nutrients it seemed to burn the tips so I'm not sure which one to use and how much. "

Your plant look nice. As said upthread yellowing fans in flower is normal. I pull them off so as to not get any disease probs from them dying off and going necrotic, I grow in soil, and have found that less is more as far as adding nutrients. Low concentrations more often (weekly?) rather than full strength nutes seems the way to go to avoid the tip burning thing.

Soil growing, with good drainage (i use a mix that 50% perllite) seems to provide a "buffer" against the kind of rapid onset nute / pH issues that hydro growers have to deal with.

 

[Chris Scorpio]

If you aren't feeding it nutes now it looks like it needs it

Start of , per Fox Farm nute Schedule at 1/4 strength, see how they do for a week or so, if they like it ramp it up to 1/2 strength and stop there. Good practice is never go above 1/2 strength of what manuf suggestes, remember they want to sell nutes....lol

They look good but are starving it appears

Nice job so far

 

[Bush Doctor 77]

Get a loupe and use it for finding critters. It will also help determining sex and time for harvest. Feed them. Most quality commercial soils and some medias are well buffered, and need no pH adjustment.

 

[OldMedUser]

What you have there is Toxic Salts Buildup or TSB. Took me years to figure out that it was my problem too. Your soil is plenty rich but your water is of unknown mineral content/hardness. Each time you water the plant drinks up the water and leaves almost all the minerals behind but still pulls up more than it can process so stores it. Eventually this builds up in the leaves and other plant tissues until the salts content gets so high it starts burning the leaves from the inside. The minerals in your water and everything your plants eat are all salts. Even with organic grows.

If your plant were starving it would steal mobile nutes from those older leaves and they would go yellow all over and be very thin and limp. When TSB is the culprit the leaves go all yellow/brown/red and feel very thick and crispy like yours look. Can sometimes happen first with the upper leaves if there are heat issues and you see the edges curling in with leaves going 'Taco' as it progresses. Especially rapid when the humidity is very low and it's too warm.

There's nothing that will fix it but you can slow the progress by flushing well and following up with a half strength dose of bloom nutes for the last part of the flush. The crop will come in fine but you may notice some 'chem' taste. A good slow-dry and a long burping session will help smooth out the smoke. That's another subject altogether.

Don't be surprised if you see even the tiny bud leaves getting burnt at the end.

 

[NuttyProfessor]

"I just use tap water, pH it to ~6.5 using a pH meter (It usually takes 3 drops of pH down for plain water), and let it sit open for a few days before I use it."

do you ph again after letting it sit out , ?

 

[1ne eye]

2018.

 

[NuttyProfessor]

to 2020 Nutty i blame the weed and @oldsmokey lol