How high EC runoff in coco

[More Overkill]

how high are growers in coco getting with ec runoff before making a change.
i find around day 40 uptake seems to slow down and the runoff goes up..fyi my grow environment is not ideal and probably slows growth towards the end.
I recently checked both plants with ec 1.3 going in and both plants had different runoff values at ec 1.7 and 2.2 i have decreased my nutrient mix by half with extra runoff to lower it.

 

[Ca++]

A 50% gain isn't unusual.
I have been in situations where 1.3 in was okay, while watching the waste didn't creep much past 2.2
Achieving this might of meant a slight lowering in the 1.3 but would more likely be extending the runoff time. It'd best not to make drastic changes, such as halving the feed or jugging through lots. Though I regularly found ailments were caused by the runoff going much further out of range, and so some instant juggling was needed.
The shift around 40 days isn't uncommon. The buds loose a lot of water, and things like calcium that are carried along through thranspiration, are less able to enter the aging root system. Thus the EC increases throughout each dryback. I have heard professors talk of feeding 2.0 which can concentrate to 6.0 and still be looking good. Which seems very extreme to me, but where we actually measure is important. Along with a substrates ability to let it all go again. In DWC trials, a weekly change out, is often accompanied by a mid week top-up with plain water. The weekly change out, often measures the same going out, as what goes in.

Without knowing a lot more, I can't say if your numbers are good in your situation. However, they don't look impossibly bad. Some longer term monitoring and logging of results is in order. The 1.7 really doesn't seem concerning though. Some gain is expected as the coco is adding salts. Plant health is the real guide here, but I imagine the 2.2 is getting a bit out of hand.

 

[More Overkill]

i have been lazy to check runoff regularly but the size of the area the plant is in makes a big difference how a plant can uptake even though evening else is close to being right like ph/nutrient/temp and so on.
from week 1 to around week 4 or 5 uptake is excellent with the runoff value is low like 0.6-0.8 but as the plant becomes more mature from then on uptake is slow and ec runoff increases, i did wait to long to make a change with decreasing the nutrient mix but it still looks ok, if i continued to use the nutrient mix recommendation it would of burn the plant severely.

 

[Ca++]

I have fed many crops with runoff value as my main guide. If you were feeding 1.3 and seeing half of that in the runoff, you should probably increase the 1.3
Watch for that tipping point, where the runoff starts to get ahead, then increase runoff an lower the feed accordingly.

Coco is interesting. If you feed 1.3 and get 0.7 back out, then the coco's condition has likely been effected. The plants probably took things that were stuck to it, and these free spaces capture the K and Na the coco is producing. The balance in the cec shifts. When you feed next, the Ca and Mg in the feed are likely to displace this K and Na. Stripping them from your feed. Giving you more K and Na to eat. It's not great, though might not be a disaster either. However, not seeing that dip in runoff numbers, means the K and Na from the coco are almost certainly in the water, ready to get washed out. Unable to displace the Ca and Mg on the coco.

Coco is conditioned before use, and it's basically that. Ca and Mg are used, to displace the K and Na coco is full of. It needs to go. In use, we have abundant Ca in coco feeds to ensure the K and Na becoming available, are displaced and leached away.
Though again, I have seen grows where no runoff was made. Fair mids were produced still.

 

[More Overkill]

i am a bit of a grow hack and it can be difficult to get it right but with my next single plant grow i'm using auto watering system i already have the gear and have used it before i have to stop doing manual watering...but i still want weed of course.

start of week 7