Here's the situation plants are 2 weeks into veg and are having yellowing/ heavy looking leaves. All together looking unhealthy. Day 1 we watered with 550 ppm 5.8 ph base nutrient + roots excelerator only. Temp is 80 and humidity is 50%. We made a slurry by taking a handful of coco and making a slurry with RO water. We let the slurry sit for 15mins. We then strain the slurry and check ppm/ph. The ph was 6.4 and the ppm was at 250. We raised the ppm to 750 for the next feeding thinking that we weren't feeding high enough. We checked the runoff with the slurry technic after the 750 ppm feeding and it was 350ppm 6.4ph. Plants still look the same. Not sure what my next action should be!! Any suggestions would be appreciated . And thanks in advance for any help
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Coco runoff confusion
- Thread starter gogeter
- Start date
W
willyweed
edit ,listen to the guy below
I kind of agree with willy . He's right the PH is to high , but you never flush coco with straight water ! you continue to feed but at a lower dose & a PH of 5.6 for about a week . & feed till alot of runoff .... about 40 to 50 % every day .... untill your PH is back in the right range of 5.6 to 6.0 . then resume your normal feedings . you do drain your runoff right ??? you never let your pots set in the runoff very long !!!! it causes salts to build up & can cause the problem your having .
when testing the runoff PH .... catch it in a cup or bucket & just test that . yeah a slurry test is the correct way ...., but its more for EC levels . i've done both ways & the PH levels have been the same in both tests ...
you don't really need to be testing all the time to see what your plants are eating .... just start with 1/2 the dose of the bottles recomendation & build up from there . your plants will tell you if the they're not getting enough or too much . read the leaves .
500 to 750 is good for veg .... 750 to 1k is good for flower .... i rarely go over 1k ... even with a PK boost .
when testing the runoff PH .... catch it in a cup or bucket & just test that . yeah a slurry test is the correct way ...., but its more for EC levels . i've done both ways & the PH levels have been the same in both tests ...
you don't really need to be testing all the time to see what your plants are eating .... just start with 1/2 the dose of the bottles recomendation & build up from there . your plants will tell you if the they're not getting enough or too much . read the leaves .
500 to 750 is good for veg .... 750 to 1k is good for flower .... i rarely go over 1k ... even with a PK boost .
Thank you both for the help! Yes I do drain the runoff. Pots are never sitting in left over runoff. I can understand the 6.4 ph being to high and flushing to fix this. But am still completely confused as to why the ppm of the slurry is so much lower than the nutrient being fed. I was under the impression that a salt build up would have increased the ppm reading in the slurry to a point higher than what was fed. Is the slurry test an accurate way to check ppm/ec?
it is if its done right ..... but its not so easy to get it right . i get different readings than what its supposed to be too . which is kinda why i gave up on slurry tests . if you slowly fill the buckets so that the water doesn't rush through the coco ... & it has a chance to saturate before it runs off .... you can get a pretty accurate idea of what the levels are if you catch that runoff in a clean cup & test that . no they won't be on the money ..... but pretty damn close 
but its not needed for feeding .... its just basicly a level test if you think something is wrong in the pots .
yes your right if the salts had built up the EC would be higher .....the low EC tells me your plants are hungry . yellowing leaves is a sign of a nitrogen Def or your PH is outa whack ..... after you flush for a couple days to get the PH in range .... start feeding them a little more than you were . if you get a tip burn ..... back off the feed strength . start low & build up , the plants will let ya know .
I'm fukin baked !!! i hope this is making sense
but its not needed for feeding .... its just basicly a level test if you think something is wrong in the pots .
yes your right if the salts had built up the EC would be higher .....the low EC tells me your plants are hungry . yellowing leaves is a sign of a nitrogen Def or your PH is outa whack ..... after you flush for a couple days to get the PH in range .... start feeding them a little more than you were . if you get a tip burn ..... back off the feed strength . start low & build up , the plants will let ya know .
I'm fukin baked !!! i hope this is making sense
J
Johnny Redthumb
You still haven't satisfied the cation exchange in the coco, that is your reason for the coco "eating" all that nutrient. Also why your plants are yellowing and your pH is drifting.
I would start over. And yes, you can flush coco with clean water, but it MUST be pH'd and then you have to feed to rebuffer your medium (i.e. balance cations).
Bring some clean water down to a pH of 5.1 and water them with high runoff. If you have access citric acid (crystal form, in a bottle), even better. The idea is to chelate all the minerals and give you a clean slate. Then you have to water in a normal feed solution immediately after, around 800-1000 ppm or 1.3-1.5 EC.
Give it a few days to correct itself, but DO NOT let the coco dry out. Water regularly with no less than a 0.8 EC solution. In the meantime, you should foliar with the micro (from a 3 part) or the part A (from a 2-part).
I would start over. And yes, you can flush coco with clean water, but it MUST be pH'd and then you have to feed to rebuffer your medium (i.e. balance cations).
Bring some clean water down to a pH of 5.1 and water them with high runoff. If you have access citric acid (crystal form, in a bottle), even better. The idea is to chelate all the minerals and give you a clean slate. Then you have to water in a normal feed solution immediately after, around 800-1000 ppm or 1.3-1.5 EC.
Give it a few days to correct itself, but DO NOT let the coco dry out. Water regularly with no less than a 0.8 EC solution. In the meantime, you should foliar with the micro (from a 3 part) or the part A (from a 2-part).
J
Johnny Redthumb
Oh, what brand coco are you using? Are you amending with anything? Mycos? Perlite?
I'm using big city mix from sanctuary soil. It has perlite/ lava rock. Its pre washed so we did no rinsing. Heavy 16 base + roots excelerator+ HB101 for foliar. Would the best way to mix the citric acid be with warm water then add to the Rez ? Or does it matter since it will be straight RO ? And thanks for your help
Trend
Member
Over complicating. Feed a&b @ 1.2 ec then add 3 ml/cal mag. Ph to 5.5 run a gallon of run off for every gallon of container volume. Feed super slow. Done. By the time they dry up they will be on the way to recovery. You can speed up the process by removing from direct light for a few days. Leaves will perk up and begin to green up shortly. Resume feeding as normal.
