I think it's a phosphrus def. looks like a lockout and falcium de have you checked into phosphors issues?
That dometim4s happens in coco and ppl tend to take it as lockout. So look into it and explore all possibilities as you on want to take he inorrect route.
Best of luck, any update ?
Sigh, Nice of you to add your 2 cents..... How much of this thread have you actually read? It would take almost all of it to get to where you are now, and to make a call.
The OP has had that res running for 4 MONTHS! What does that tell you? What does that really tell you? His pH is staying controlled.....so where does the "lockout" come from? It's a chemical reaction "block",
not a "lockout" (I find them as 2 different things - makes it easier to explain and on how to treat it!).....from that 4 months of no dump and refill....If you don't understand that...Here's a learning experience....
First off, (to make my case) How is he getting a def. from what he's feeding and how he tops off that res.? He's giving proper amounts of nutes, right? The res contents and the plants have been together way to long! Some things get used at differing rates. Some things build up and react with others cancelling them out in the process....See where I'm going with this?
It's the basic reason many nutrient lines are in 2-3 bottles. Some of the source chems used, will react with others. Sometimes things are in concentrations that would react with others. No matter the source chem.
So, in a res kept for long periods. The plants use the different chemical compounds at differing rates. Some are used well, some are not and build ups happen. The chem build up can at some point get to the point where it's affecting the other chems it can react with, that is exactly what happens! The concentrations get high enough to begin to cancel each other out, or simply begin to "block" one or the other out.
Zinc, Iron, copper, Calcium and Mag all can effect the P uptake. The list I gave is in basic order of what will have the greatest negative or "blocking" power to P, the more there is. The same is true for the reverse! Too much P and you'll see the blocking start with Zinc first and then roll down the line, the more P is present....(High P is THE most common problem in bloom - You see it all the time by the yellowing of lower leaves and it progresses up the plant till hitting even the small bud sugars and then the buds them selves!) The more it blocks the elements down that line!
As a res sits...Minerals build as the plants use them less then macro's......What I see is this blocking process taking a real foot hold here......The solution is
NOT to add "more" but, to dump the contaminated res and work fresh clean nutrients, at proper ratio's!
Understand?
@SDK420 As far as any yield estimate......I won't do that...... Even with all my years. I don't like to count the chickens before the eggs hatch! Even wet to dry conversions can vary to much for me.....guess I'm patient that way.
Either dump and refill that res to continue, or dump and flip to bloom...I would do one or the other, depending on what I needed in height.