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plants are still yellowing at 1800 tds wtf!

T

TREE KING

sorry i probably should of started this thread in the cannabis infirmary section

its insane whats going on with my plants right now. i got plants that have been in flower 13 days that ive been flooding once a day except yesterday i flooded twice for the first time. im using 4" squared pargro quick drain stonewool cubes. when the lights come on the plants are extremely light green and yellowish then when i flood them with 1800 ppm an hour or 2 later they turn solid green again. the same thing happens every day and every day i raise the ppm by 200 thinking its gonna stop happening and there being underfed. i started off at 500 tds and ive had to raise it so much that im at 1800 now. could my plants really need this much nutes or do you think flooding more at a lower tds will fix the problem? my biggest plants are 2 ft tall and theres only a few roots coming out of the bottom of the cubes. the cubes never feel too dry to me even before the lights shut off so it doesnt seem like its under watered. just so you know other than this problem the plants are extremely vigorous and healthy. just to add theres no way its a ph problem. ph has been 5.6-5.8

this is fucking insane! the lights just turned on and of course i go into the grow room and there yellowish again. it never fails, everytime the lights turn on there starving.i just up my nutes again to 1900 and watered them. they will be fine in an hour or 2 but this is insane. i even flooded them twice yesterday for the first time and before the lights went off they were perfectly fine and solid green. i watered them once when the lights came on and again 6 hours later. i checked the res as soon as the lights came on a half hour ago and without topping off the res was below 1800 at 1750. i always here alot of people say thats a signal to add nutes. the thing thats fucked up too is my meter only goes to 2000 and my water is at 120 tds. if i raise nutes further up i wont even be able to tell the strength anymore! craziness.

i just wanna make sure you guys have the most info possible.

strain-blubonic
humidity- 45-50%
ph-5.6-5.8
temp 78-80f
nutes- nothing but sensi 2 part and big bud
medium-pargro 4" squared stonewool cubes

im keeping my moms under a 400 watt mh at 1000 tds and they have been fine. one time i accidentally let the cubes dry out and i noticed the leaves on the plants started to sag but stayed green. this is why im thinking the problem in flower has nothing to do with watering. im using different cubes in the mother room though. grodan 4" squared cubes. what do you guys think?
 
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BigDawg

Member
don't you suppose to be flooding 3 times a day or something? 1800 seems kinda high for 2 ft plants and such little roots? Shrug, let's see what others say.
 
T

TREE KING

don't you suppose to be flooding 3 times a day or something? 1800 seems kinda high for 2 ft plants and such little roots? Shrug, let's see what others say.

i hear you but usually from what ive scene plants dont yellow from being under watered they droop and theres still water in the medium. i shouldnt have to flood the plants during the night cycle and before the lights go out the plants look fine. i hear you lets see what others gotta say
 
T

TREE KING

did the yellowing start on new growth or oldest?

the new growth and i just looked at the plants. on the new growth the part of the leaves closest to the stem is yellowing. as the leaves get closer to the tips they get greener. wow this time it looks like the yellowing isnt disappearing so im gonna have to give them another watering right now to see if it clears up. i dont know if i should up the nutes more but im gonna give them a second watering and see what happens. since its been 4 hours since the light came on im gonna water them now and in another 4 hours so that would equal 3 waterings for the light cycle. i cant wait to switch to aeroponics cause then i wont have to worry about how many times a day to flood the tray. this is gettin ridiculous. maybe i just have to flood it more cause there pargro quick drain cubes
 
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have you checked the runoff of your cubes? i've had an issue like this before, feeding some where around a ph of 5.8-6 but the run off has been up around 7, this was with pre-soaked cubes and the lot, not sure what made that happen but yeah..i would look into that.
 
T

TREE KING

have you checked the runoff of your cubes? i've had an issue like this before, feeding some where around a ph of 5.8-6 but the run off has been up around 7, this was with pre-soaked cubes and the lot, not sure what made that happen but yeah..i would look into that.

i dont know what that is. how do you measure the run off? just to add i have another strain in my ez-cloner and there taking alot more nutes than i thought also. i got my newly rooted clones up to 1000 tds now. i never thought i would be having yellowing problems at 8-900 tds. i used to think people were crazy when they were saying they give there plants 1500-2000 tds but now im starting to realize maybe thats what some strains really take lol

i now have my timer set to flood 3 times a day at 1900 tds. if after these 3 floodings the lights come on tomorrow and the plants look kind of yellow than il have no other choice than to raise the nutes up further and i got no idea how im gonna be able to measure the tds.
 
G

Guest 150314

If its new growth what your describing sound like magnesium deficiency, flush them with h20 and cal-mag. I think you are feeding to heavy which is most likely locking out magnesium.
 
T

TREE KING

If its new growth what your describing sound like magnesium deficiency, flush them with h20 and cal-mag. I think you are feeding to heavy which is most likely locking out magnesium.

hell no! with all do respect there not getting enough of something it being waterings or nutes. flushing is the last thing i should do in this situation. my ph has been on point from day 1. the plants are growing very vigorously and like i said before this has nothing to do with ph. not to be disrespectful but i know thats not the right move. i will destroy the whole crop if i do that

if i was feeding too heavy they would be dark green and have tip burn or have the claw. thats not it. i probably would of been better off if i gave them grow nutes the first 2 weeks
 
T

TREE KING

gotta run out for a few hours il be back. i appreciate everyone trying to help
 

krunchbubble

Dear Haters, I Have So Much More For You To Be Mad
Veteran
If its new growth what your describing sound like magnesium deficiency, flush them with h20 and cal-mag. I think you are feeding to heavy which is most likely locking out magnesium.



BINGO BANGO!!!!

WE HAVE A WINNER!!!
 
G

Guest 150314

hell no! with all do respect there not getting enough of something it being waterings or nutes. flushing is the last thing i should do in this situation. my ph has been on point from day 1. the plants are growing very vigorously and like i said before this has nothing to do with ph. not to be disrespectful but i know thats not the right move. i will destroy the whole crop if i do that

if i was feeding too heavy they would be dark green and have tip burn or have the claw. thats not it. i probably would of been better off if i gave them grow nutes the first 2 weeks

Ok then, keep frying them. Don't listen to me I don't know anything.

You are feeding to much, to much potassium will cause magnesium deficiencies.. and I don't see how you can tell if your ph is on point if you aren't checking run off. Acidic ph is another cause of mag deficiency.
 
i dont know what that is. how do you measure the run off? just to add i have another strain in my ez-cloner and there taking alot more nutes than i thought also. i got my newly rooted clones up to 1000 tds now. i never thought i would be having yellowing problems at 8-900 tds. i used to think people were crazy when they were saying they give there plants 1500-2000 tds but now im starting to realize maybe thats what some strains really take lol

i now have my timer set to flood 3 times a day at 1900 tds. if after these 3 floodings the lights come on tomorrow and the plants look kind of yellow than il have no other choice than to raise the nutes up further and i got no idea how im gonna be able to measure the tds.

when the cubes get soaked next time, wait a little while then gently squeeze some water out into a thin cup or something, check the PH of that...

these guys also have a very valid point, feeding too much of one thing will lock out others, with your EC i wouldn't be suprised if it is lock out.
 
T

TREE KING

Ok then, keep frying them. Don't listen to me I don't know anything.

You are feeding to much, to much P will cause magnesium deficiencies.. and I don't see how you can tell if your ph is on point if you aren't checking run off. Acidic ph is another cause of mag deficiency.

ok i just got back and my plants are solid green. like i said in my first post i started feeding at 500 tds. so i guess i was overfeeding then huh? the only reason i raised the nutes above 500 is because of the yellowing. like i said before this has nothing to do with my ph. you can either believe it or not but it is what it is. i gotta go to sleep now so il deal with this tomorrow. even though you guys disagree with me i still appreciate your help. my ph has been on point from day 1 and the plants are growing vigorously. i dont even know what to say anymore i might just have to figure this out for myself.
 
the ph of your cubes can change, i have had cubes that i soaked in a low ph for 24 hours, grew plants fine for a few weeks then had issues, tested runoff from the cubes was much higher than what i was feeding, so even though you're putting in 5.8 it may be alot higher in the cube once it mixes...

i think its more likely you've had a low feed issue, tried too much to correct it and caused lock out.
 
T

TREE KING

the ph of your cubes can change, i have had cubes that i soaked in a low ph for 24 hours, grew plants fine for a few weeks then had issues, tested runoff from the cubes was much higher than what i was feeding, so even though you're putting in 5.8 it may be alot higher in the cube once it mixes...

i think its more likely you've had a low feed issue, tried too much to correct it and caused lock out.

raising tds 200 a day isnt too much to cause this lockout your talking about. also lockout doesnt cause the rez tds to drop before top off. that means plants are eating like crazy. keep in mind yesterday my res was at 1800 then after i flooded, the next day the res was at 1750 before top off. pardon me while i pass out
 

SacredBreh

Member
TDS is a very poor way to monitor nutes......

TDS is a very poor way to monitor nutes......

TDS is based on EC but there are 3 different coefficients for EC. TDS is arrived at from a calculation starting with an EC. When my plants are telling me one thing and my meter is telling me another I go with my plants. I would get a good meter that reads EC directly.

New growth can be lighter in the morning than it is later in the day especially during rapid vegitative growth. Mg and Zinc deficiencies can cause light new growth but both usually cause the new leaves to be deformed and don't usually get better by the end of the day.

It could be that the 4in cubes do not sustain the nutrient requirements over a 24 hour period despite staying moist. (not likely unless the meter is reading off)

I am a DWC person myself but have done flood and drain in the past and flooded 3 times during the day and 1 time in the middle of the night but this is 12/12 because I went straight from clone to flower.

Have you calibrated your meter?

Peace
 
T

TREE KING

TDS is based on EC but there are 3 different coefficients for EC. TDS is arrived at from a calculation starting with an EC. When my plants are telling me one thing and my meter is telling me another I go with my plants. I would get a good meter that reads EC directly.

New growth can be lighter in the morning than it is later in the day especially during rapid vegitative growth. Mg and Zinc deficiencies can cause light new growth but both usually cause the new leaves to be deformed and don't usually get better by the end of the day.

It could be that the 4in cubes do not sustain the nutrient requirements over a 24 hour period despite staying moist. (not likely unless the meter is reading off)

I am a DWC person myself but have done flood and drain in the past and flooded 3 times during the day and 1 time in the middle of the night but this is 12/12 because I went straight from clone to flower.

Have you calibrated your meter?

Peace

"It could be that the 4in cubes do not sustain the nutrient requirements over a 24 hour period despite staying moist."

after thinking about this thats the only thing that makes sense. but the thing i dont understand is why would the plants look totally fine before the lights go out and then when the lights turn on be deficient? i heard even some people that do aeroponics turn the pump totally off during the night cycle. maybe thats not true i dont know but this guy at a grow store was telling me that and also people always say plants dont feed during the dark cycle.

just to be a little safer is there another ph level that will bring in more magnesium? what ph would that be?

i think im also gonna flood the table once in the middle of the night to be safe. wait a minute do people flood during the dark cycle when there using hydroton only for there medium? if they dont then i shouldnt have to cause my medium holds more water than that

my tds meter is the kind where it doesnt require calibration. what i do is every now and then i test plain water and it always reads 120 so i just minus 120 off when i measure my nutes
 
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T

TREE KING

Check this out, it might be more tangible to you...............perhaps. What you are describing sounds like iron or zinc, or at least some type of micronute issue, IMHO. The link might help it make sense why less is more in these cases:

http://scienceinhydroponics.com/201...what-pushing-out-an-element-really-means.html

thanks for posting that article. the thing is when i started my nutes at 500 i was having the problem and i slowly raised my nutes 200 tds a day but the problem didnt go away until i raised it alot higher. very weird. i never had this problem when i was using the grodan rockwool cubes
 

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