sick plant 7th wk of flowering, please help.

[OcMaster]

2 Kimbo Kush
3 gallon pot w/ coco 70 and perlite 30
Mars300, and viparspectra par600
Tap water sit 24hrs, ppm 350 ph 8.1
Fed twice lights on, 10-20% run off
Nute: sensi bloom a&b coco, rhino skin, calmg, bud candy, big bud coco, drip clean, molasses (only use it twice).
PH 5.6-6.3, ppm 1000-1300 (before nute burn and flush)
Now: ph 5.6-6.2, ppm 500-700

I was doing great till past week 4 flowering. Saw sign of nute burn so I did a flush mid week 6. Bought water for lower ppm. Did a flush with ppm (very small nute added 1/4 of label) under 400, ph 5.8. Runoff went from 1400 ppm / ph 5.9 to 350 ppm / ph 5.8 for 2 days.

After a few days I still see the nute burn starting on the edge of the fan leaves. Now I am seeing bronze spot on the leaves. The leaves are dark green waxy color look. Please help. Is it mag deficiency? Yesterday I added a little more Calmg. Still only at 700 ppm feed currently because nute burn on edge. What am I doing wrong or how do I fix this problem. Getting closer to the finish line only to choke is no fun. Btw plant been in 3gallon since clone in cube. Could this be the problem with root bound?

Wk7 my trichomes are still all clear. So I am guessing I am looking at 9-10 wks.

Here are a few shot, mostly on 2 branches fan leaves, afraid it will spread to the rest.

[Lotusyde]

From what I understand you want your ph at 6.5 - 7. 8 is too high and is most likely locking nutrients out of your roots.

[OcMaster]

I am in coco, ph range is 5.5-6.5 and anything more or less is not ideal. My ph never get pass 6.5. I do 2 gallon mix every 2ish days. So ph goes go up but usually it only go up .2-.3 most in 1 day. After the first day mix at 5.7, 2nd day it is 6.0 and by then I am done and do another mix the next day.

[9fingerleafs]

Everything looks pretty good. Even when you fix any burn the tips won't recover. Keep those ppm in check. You have no deficiencys and after week 7 there's no need for nutes (n-p-k). Maybe just some molasses or bud candy to finish up. Keep flushing so nothing builds up. You are doing great

[OcMaster]

Yea I understood the burn tip is done forever. Question... at 7 wk in my trichomes are all clear, should I just keep on light nutes till 2 week from harvest. I don't see any cloudy trichomes so I am thinking 3 more wks at least if not longer. Should I stop feeding nute because this doesn't seem like 8wks rdy to flush.

[9fingerleafs]

i think after 7 weeks of flowering most of the times, there`s no need for heavy potassium and phosphorus feeding, i would suggest you stop using bloom and lower the dose on everything else, this way the plant is gonna use the nutrients it already has, thus preventing minerals builds ups and further burn

[Green75]

Coco...ph at 6..Brown spots

[OcMaster]

Since different ph let different nute absorb effectively, is why I let the ph slip up. First day ph 5.7-5.8, end of 2nd day of water ph, 5.9-6.1.
I guess I will keep it under 6 till I finish harvest.

[Green75]

Feed her till last week and 1/2....then flush/strip.... Last few weeks are crucial for putting on weight...proper care of medium through whole grow with stripping/flushing...will never allow plant to block nutrients...Feed them....

I feed three times then flush/strip them...

A plant should only have to feed off itself in times off self preservation...

The last week before harvest...when you flush them...they are drinking crazy...the plain ph water will allow them to rinse their plumbing out...

Last weeks before harvest is crucial..that's when weight and resin really pack on...it's a waste to deprive them till the end...

As usual just my $.02