Overwatering? Deficiency? Burn? What gives?

Growing in 5 gal buckets of sunleaves coco coir (piece/classic 50/50) amended with bone meal, blood meal, biotone, rock phosphate, kelp, lime.

Watering with R/O water, using the Fox Farm soil pack trio (Grow big, big bloom, tiger bloom) according to fox farm schedule(half strength), along with molasses here and there.

Had read about coir's need to be watered frequently, that it cant be overwatered. Frequent (daily) waterings seemed to be beneficial for the first few weeks of flowering. Around week 4 some leaf yellowing and drop began, watering frequency decreased, buckets allowed to dry almost to a wilt, yet the yellowing and leaf drop are gradually increasing, moving from the lower, to the middle, to the upper leaves. Also, density, trichome production, and aroma don't seem to be on par with past experiences from these strains.

We are now on day 45, and here are a few pics, Ill try to get a few more soon.

Just wanted to add, that my light is a 600w hortilux enhanced hps, air cooled with a 6" inline suncourt fan on intake and exhaust. The cab is exhausted through a homemade carbon filter using a stanley blower. The fans are on the timer with the lights so they go off during the dark phase.

Could the low daytime humidity along with higher nightime humidity be contributing to this issue? Should I have the ventilation running 24/7 despite RH issues?

Temps drop as low as 58 - 65 degrees at night and get up to 80-85 tops.

sounds like maybe cal mag deficiency......

hmm, could be, I am in coco, and used garden pelletized lime instead of powdered. But I have been using grandmas mollases with calcium, iron and magnesium.

Im thinking i might have a lockout from too much P (I used espoma triple phosphate 0-43-0). Definitely not using that this time. This is just an assumption though, I would still like some other opinions.

what is your PH?

I havent watered in a few days, should be tomorrow, or the next day the latest. I'll try to collect a little runoff and test it.

IT, u've got a few issues going on... would strongly suggest reading through the Coco Coir Forum, there will be a lot there though...

BTW, can't access your pics- could u post in text? Did u check my response to your bug issue- which coir u using? Pics will help me give you specifics...

First, without looking, coir is not like soil, especially for watering. When you reduced your watering schedule down from daily, you began to create problems, if others didn't already exist. Coir needs to stay wet- do not use wet/dry schedule like soil. This will create pH shifts within your pots, which will then create multiple lockout. Also, your drying of the coir is going to contribute to salt accumulation, throwing pH & EC off- again, they can't feed. Most of your current problems probably stem from this...

Second, you can get away with amending your coir & possibly running FF nutes, but again, it is NOT soil, and you really, really can not treat it like such. You should be running a hydro nute with CaMg supplements, or a coir specific hydro nute. This is problematic with your existing coir amendments though... BTW, MO (molasses) is not viable source to supplement Ca, Mg, Fe- use CaMag+ or SensiCal. Also, MO has Na, measured in mg... you really don't want that.

You're in a tough position now, especially at wk6. Flush the heck out of things today. You're EC will probably be high & the pH very low. Get things back into balance the best that you can, but start focusing on the next run- read about coir specific concerns. Do not apply anything from your soil growing days- it will only create problems like you are currently experiencing. Again, not much you can do now, but best regards.

Thanks pokerfish. I saw your responses in the other thread, but I had added the DE already.

Do you not see my pics right in the thread? They are right in my post, and attached as well. This new forum is bonkers. I had to be logged in before I could see them, though, if that helps.

I have read the coir forum, as well as the organic soil forum. Im confused because in the organic forum, there are tons of people that use coir as a peat substitute, and treat it like any other soil/soiless mix.

I understand coir by itself is to be treated like hydro, but its also considered a peat substitute, right? I guess if I add worm castings, or compost that would change things a bit.

Also, the FF has only been used a couple times, at half strength. Other than that, just straight water and molasses has gone in. How could there possibly be a salt accumulation?

About molasses, (from the 3LB guide)

"It’s primary use would be to treat plants who are deficient in Potassium, although molasses also provides significant boosts in other essential minerals such as Sulfur, Iron and Magnesium."

"For gardeners the sweet syrup can work as a carbohydrate source to feed and stimulate microorganisms. And, because molasses (average NPK 1-0-5) contains potash,
sulfur, and many trace minerals, it can serve as a nutritious soil amendment. Molasses is also an excellent chelating agent."

Understand that Im not trying to undermine your advice, Im merely trying to gain a greater understanding of information and techniques that at present, seem to be somewhat contradictory. I am very grateful for your willingness to help me figure out my problems.

I'm with poker on this. You probably already had a typical mg defic in coco, then you started locking up with ph swinging. Don't know about them organic ferts are burnin you up at half strength, and your doing runnoff checks unless..
Your reading the Ppm w the wrong conversion or your running organics like hydro, where we read the true ppm as they are elemental salts. Organic will only read about half of what is actually there because it must be broken down unlike salt based hydro ferts. If your pen reads 1000, think 2000! When in doubt, flush em out! As most of the foliage is yellow, start flushin and wrap it up. I don't expect your plants to revive, the chlorophyl is gone... Can't photosynthesize with out chlorophyl.... I know... More like bore-o-phyl...
Sucks!

Id hit um with a full dose of nutrients and 2ml cal-mag, ph'd at 5.8-6, you still got 2-3 weeks by the look of things, and they still got some green in um too.

thats called a nitrogen deficiency. if you're close to the end just let it go. no point in feeding nitrogen at the end of flower.

Thanks for all the help guys.



So, which is it though? Nitrogen is what I thought originally, because during the 3-4 week, FF recommends adding 2 tsp grow big on top of the tiger and big bloom, but I chose to not add any grow big.

I will be doing another go over of the coir threads. I have some sunleaves piece coir freshly rinsed that I havent mixed with anything yet. Im thinking of doing a few plants straight in this, watering with 8ml FNB, and 1ml FL+ per gallon, with every watering, done once a day. Is this a feasible plan?