So I have two northern lights (so I've been told) plants going. Both have been in flowering since the end of October. One is doing real well the other is getting yellow leaves then they turn brown and fall off. I put the light up higher around 1 and half feet above thinking it might be light or heat stress. It does seem to be stunted a little bit. Can anyone help? They are under two 300w LED lights and are in 7 gallon grow bags.
Flowering Help Needed
- Thread starter BVassy24
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OldMedUser
Well-Known Member
Classic nute burn. You'll need to lower the amount of nutrients in the soil by flushing some plain water thru. RO water is the best for that as it has no minerals in it so can leach out excess salts better than tap water.
Speaking of water what are you using? Hard water leaves it's minerals in there as the water is used up by the plant and builds up over time like the scale in a kettle. Along with fertilizer salts it leads to toxic salts buildup and around mid-flower starts looking like what you've got there. The leaves get very hard and crispy and it can progress right into the buds if not dealt with. Low RH contributes to that too as the plant transpires a lot more water thus drawing up excess nutes that build up in the leaves and leads to burn.
I'd flush thru at least 1 volume of your pot size so 7 gallons of water to drop the mineral content of the soil. A complete flush takes 3 volumes of water with the last volume being a 1/4 to 1/2 strength nutes so the poor thing isn't starving while you wait for the soil to dry out enough for another watering and feed. Just bloom nutes at this stage of flowering as they can steal N from the old leaves as they need it like they do in nature.
Good luck!
Speaking of water what are you using? Hard water leaves it's minerals in there as the water is used up by the plant and builds up over time like the scale in a kettle. Along with fertilizer salts it leads to toxic salts buildup and around mid-flower starts looking like what you've got there. The leaves get very hard and crispy and it can progress right into the buds if not dealt with. Low RH contributes to that too as the plant transpires a lot more water thus drawing up excess nutes that build up in the leaves and leads to burn.
I'd flush thru at least 1 volume of your pot size so 7 gallons of water to drop the mineral content of the soil. A complete flush takes 3 volumes of water with the last volume being a 1/4 to 1/2 strength nutes so the poor thing isn't starving while you wait for the soil to dry out enough for another watering and feed. Just bloom nutes at this stage of flowering as they can steal N from the old leaves as they need it like they do in nature.
Good luck!
So I just fed them not knowing it was nute burn. Can I flush out now or should I wait? I don't want to over waterClassic nute burn. You'll need to lower the amount of nutrients in the soil by flushing some plain water thru. RO water is the best for that as it has no minerals in it so can leach out excess salts better than tap water.
Speaking of water what are you using? Hard water leaves it's minerals in there as the water is used up by the plant and builds up over time like the scale in a kettle. Along with fertilizer salts it leads to toxic salts buildup and around mid-flower starts looking like what you've got there. The leaves get very hard and crispy and it can progress right into the buds if not dealt with. Low RH contributes to that too as the plant transpires a lot more water thus drawing up excess nutes that build up in the leaves and leads to burn.
I'd flush thru at least 1 volume of your pot size so 7 gallons of water to drop the mineral content of the soil. A complete flush takes 3 volumes of water with the last volume being a 1/4 to 1/2 strength nutes so the poor thing isn't starving while you wait for the soil to dry out enough for another watering and feed. Just bloom nutes at this stage of flowering as they can steal N from the old leaves as they need it like they do in nature.
Good luck!
OldMedUser
Well-Known Member
If you wait it'll just get worse so might as well flush it now.
I don't suppose you have an air pump that you can use to aerate the water first do you? It helps if it has as much oxygen in it as it can hold before using it. Even pouring back and forth a few times in buckets will get more air into it first. Lack of oxygen in the root zone is what causes rot with overwatering. I have a little aquarium pump that I use just for that. I just drop the stone into a fresh jug of RO water and plug it into the power bar that my light timer is connected too. Then when go to use the water I know it's charged up.
Even with a flush you're going to see more damage. The salts are already built up in the leaves and flushing the soil won't change that. Things like Final Flush can be used but I've seen that go sideways and basically desiccate the plants so they can die and you don't want that.
I was always having problems like what you got going and for a long time thought it was just too much N in the 2-part nutes I was using but about a year ago read about Vapour Pressure Deficit. Up north here the air is very dry and it's hard to keep the grow room above 30% humidity. For my last grow I reduced by about half the nutes I was giving them and it seems to have worked as all the plants, about 25, finished up with nice soft leaves with no hint of burn or salts buildup.
As it's near impossible to keep the RH without going into a sealed room scenario and all that entails I'm just going to see if reducing my ppm in DWC gets me good results. Worked OK with the last grow in pots of 50:50 soil:soilless so I'm pretty sure I'm on the right path.
Overwatering causes problems when it goes on for a while, If the pots are never allowed to dry out and draw air into the root zone it becomes stagnant which sets the stage for the ever-present bad bacteria to bloom and start up the rot. They don't like O2 whereas the good bacteria love it.
I don't suppose you have an air pump that you can use to aerate the water first do you? It helps if it has as much oxygen in it as it can hold before using it. Even pouring back and forth a few times in buckets will get more air into it first. Lack of oxygen in the root zone is what causes rot with overwatering. I have a little aquarium pump that I use just for that. I just drop the stone into a fresh jug of RO water and plug it into the power bar that my light timer is connected too. Then when go to use the water I know it's charged up.
Even with a flush you're going to see more damage. The salts are already built up in the leaves and flushing the soil won't change that. Things like Final Flush can be used but I've seen that go sideways and basically desiccate the plants so they can die and you don't want that.
I was always having problems like what you got going and for a long time thought it was just too much N in the 2-part nutes I was using but about a year ago read about Vapour Pressure Deficit. Up north here the air is very dry and it's hard to keep the grow room above 30% humidity. For my last grow I reduced by about half the nutes I was giving them and it seems to have worked as all the plants, about 25, finished up with nice soft leaves with no hint of burn or salts buildup.
As it's near impossible to keep the RH without going into a sealed room scenario and all that entails I'm just going to see if reducing my ppm in DWC gets me good results. Worked OK with the last grow in pots of 50:50 soil:soilless so I'm pretty sure I'm on the right path.
Overwatering causes problems when it goes on for a while, If the pots are never allowed to dry out and draw air into the root zone it becomes stagnant which sets the stage for the ever-present bad bacteria to bloom and start up the rot. They don't like O2 whereas the good bacteria love it.
Awesome, Thanks for all this info. I do have a little pump I can use. I'll flush ASAP. I just have one more question. Should I ph the water I'm going to flush with?
OldMedUser
Well-Known Member
Depends on what water you are using. RO water doesn't need to be pHed as it has no real pH of it's own. Tap water on the other hand should be adjusted. If you have a lot of minerals from tap water built up in the soil then going down to pH 5.5 is helpful to reduce the alkaline minerals that keep the pH too high in there. I never run into that as I only use RO water and pH Perfect nutes. My last grow and for most grows I've done in the last 17 years I've never needed to flush unless I get the same thing going on that you have.
In DWC I rarely change nutes more than once right after the stretch and after doing a side-by-side grow with two tubs full of plants and not changing one at all I often skip the one flush and go all the way without ever changing nutes and get good grows. I'm too cheap and broke to be tossing out perfectly good nutes every week like they want you too. Makes them richer and me poorer.
In DWC I rarely change nutes more than once right after the stretch and after doing a side-by-side grow with two tubs full of plants and not changing one at all I often skip the one flush and go all the way without ever changing nutes and get good grows. I'm too cheap and broke to be tossing out perfectly good nutes every week like they want you too. Makes them richer and me poorer.
I normally use Walmart brand spring water. I'll be using a few gallons of tap that has been sitting out for a week.Depends on what water you are using. RO water doesn't need to be pHed as it has no real pH of it's own. Tap water on the other hand should be adjusted. If you have a lot of minerals from tap water built up in the soil then going down to pH 5.5 is helpful to reduce the alkaline minerals that keep the pH too high in there. I never run into that as I only use RO water and pH Perfect nutes. My last grow and for most grows I've done in the last 17 years I've never needed to flush unless I get the same thing going on that you have.
In DWC I rarely change nutes more than once right after the stretch and after doing a side-by-side grow with two tubs full of plants and not changing one at all I often skip the one flush and go all the way without ever changing nutes and get good grows. I'm too cheap and broke to be tossing out perfectly good nutes every week like they want you too. Makes them richer and me poorer.
OldMedUser
Well-Known Member
Spring water is pretty high in minerals as well. Do you know the ppm of your tap water?
I'm paying $3.49 for a 5gal jug of RO but hoping to get my own RO unit soon if I can sell my distiller. Our tap water comes out of a dugout on my property and isn't good for much more than baths, laundry and doing the dishes. Going to need better filtering to use it to get RO water. We already filter it down to 5micron and that's the best filter that comes with RO units but I can order ones that go down to 0.5micron to get the finest particles out.
How much does that spring water cost?
I'm paying $3.49 for a 5gal jug of RO but hoping to get my own RO unit soon if I can sell my distiller. Our tap water comes out of a dugout on my property and isn't good for much more than baths, laundry and doing the dishes. Going to need better filtering to use it to get RO water. We already filter it down to 5micron and that's the best filter that comes with RO units but I can order ones that go down to 0.5micron to get the finest particles out.
How much does that spring water cost?
IDK the ppm and the water is like 98 cents a gallonSpring water is pretty high in minerals as well. Do you know the ppm of your tap water?
I'm paying $3.49 for a 5gal jug of RO but hoping to get my own RO unit soon if I can sell my distiller. Our tap water comes out of a dugout on my property and isn't good for much more than baths, laundry and doing the dishes. Going to need better filtering to use it to get RO water. We already filter it down to 5micron and that's the best filter that comes with RO units but I can order ones that go down to 0.5micron to get the finest particles out.
How much does that spring water cost?
OldMedUser
Well-Known Member
I encourage people to get a water report from their provider if they use tap water. Sometimes they post it on the town's website, or like here, I just called the town's works office and they emailed me one for free. Tell them you want to raise fish or make beer or wine and need to know what the water is like if they get nosy.
I know the ppm of our water is around 400 and that will screw up an indoor grow pretty quick.
I know the ppm of our water is around 400 and that will screw up an indoor grow pretty quick.