Oldest leaves turn brown and crispy

[ulysees]

I've been growing in hydro for some time. Had some very successful grows, some not so much.

I use RO water, until recently I used the FloraGrow series, this grow I switched to Advanced Nutrients for the PH balancing feature. I'm using LED grow lights kept the proper distance from the plants, 24 light cycle. I check my PH daily and keep it close to if not in the proper range: 5.5-6.5. I consistently get older leaves that look like below. The plants grow well and produce fairly well but consistently throughout the grow cycle the oldest leaves start to turn like this. Always older leaves, whether plant is six inches or two feet. New leaves come in healthy and green, as they increase in size they start to look like this until they're dead and crispy. It seems to get worse as the plants get older but happens all through the grow cycle. I've looked through dozens of troubleshooting charts without seeing anything that looks like this. Also note that this is an ongoing problem that also occurred with Flora. One of the reasons I changed.
Additional info: 60 liter bubble container, four plants of varying size. Using about two thirds the dosage AN recommends. Humidity is 50 to 60%, temp is 65-68F. Full spectrum 1000w LED grow light with UV and IR, 18 inches above the tallest plant, on a moving track that traverses the length of the tent twice in 12 hours, so no plant sits directly under the light all the time.
Anyone have any hints?

 

[013]

What’s your temps & rh?

Apologies forgot to re-edit that first sentence before I posted and ran out the door. Anyways with temp & rh interconnected the way they are your rh is good but temps are off, need to be aiming for 80 to 84

Ph is logarithmic scale so the difference between hydro at 5.8 and soil at 6.3 may not sound like a lot but actually it’s a huge variation. For hydro you should be aiming at 5.8

When nutes are out of ph range it’s like they are not even present since the plant can’t access the stuff out of range. But here’s what’s most perplexing to me… if AN’s products are ph perfect then why does it need adjusting in first place?

Anywho I’m a just dirty dirt guy but some of the hydro peeps will stop by soon hopefully

 

[ulysees]

So far I've seen good results with Advanced Nutrients compared to FloraNova. PH would vary wildly with Flora, several points a day sometimes. With AN it settles and stays but sometimes it's not right where I want it. Then when I try to change it, up or down, sometimes I go too far. As you said it's logarithmic: for instance 8ml of PH down gets me a 0.20 drop, then 10ml gets me a 3 point drop. But as far as I can see if you leave it alone it does keep the PH stable, it just may not be stable where you want it. But it's been staying pretty close to 5.5 to 6.5, never higher than 7 or lower than 5.
But like I said, I've studied all the leaf troubleshooting guides I can find and I've never seen anything in any of them that looked like this.

 

[bluter]

if you are using the ph perfect line you get cornered into running it as is without ph'ing. it does not play well with ph balancing at all. you'll have nothing but issues.

if you want to control ph balance yourself then drop that line. even AN's regular line would be better. otherwise run without ph and leave it to AN whether it makes it or not.

 

[Delps8]

I've been growing in hydro for some time. Had some very successful grows, some not so much.

I use RO water, until recently I used the FloraGrow series, this grow I switched to Advanced Nutrients for the PH balancing feature. I'm using LED grow lights kept the proper distance from the plants, 24 light cycle. I check my PH daily and keep it close to if not in the proper range: 5.5-6.5. I consistently get older leaves that look like below. The plants grow well and produce fairly well but consistently throughout the grow cycle the oldest leaves start to turn like this. Always older leaves, whether plant is six inches or two feet. New leaves come in healthy and green, as they increase in size they start to look like this until they're dead and crispy. It seems to get worse as the plants get older but happens all through the grow cycle. I've looked through dozens of troubleshooting charts without seeing anything that looks like this. Also note that this is an ongoing problem that also occurred with Flora. One of the reasons I changed.
Additional info: 60 liter bubble container, four plants of varying size. Using about two thirds the dosage AN recommends. Humidity is 50 to 60%, temp is 65-68F. Full spectrum 1000w LED grow light with UV and IR, 18 inches above the tallest plant, on a moving track that traverses the length of the tent twice in 12 hours, so no plant sits directly under the light all the time.
Anyone have any hints?

Air temp is in the 60's and that RH are brutal on a plant. Check the VPD chart below. Your grow is running at 0.6 which is wetter than it should be for germination.

At those temps growth will be very slow and the relatively high RH makes it very hard for the plants to transpire. It's like a cold, wet blanket sitting on the leaves. Since they are having a hard time releasing water, they're having a hard time taking up water. That can lead to nutrient imbalances if you don't adjust your EC.

You might want to get your head around VPD. A lot of growers proudly state that they don't care or believe in VPD which is unfortunate since plants live and die by it. This may well be what you're running into.

What's light are you using and what's your dimmer setting? I strongly recommend that growers spend $32 for a light meter that will "remove all doubt" when it comes to light levels.

What's your water temp? As temperature falls, dissolved oxygen goes up but as temp continues to drop, you can have problems with nutrient imbalances. I had the hardest time remembering which chemical stopped being taken up at 64° until I figured out "When you hit 64, it's sometimes hard to pee." As men in our "late 50's", you, bluter, and I will understand that little nugget of wisdom. ;-)

pH ranging from 5 to 7? Wow, that's a very wide range and the swings just mean that there's more time when nutes are not avaiable to the plant. The "optimal" level is 5.8 but a lot of growers do fine in the 5.5 to 6.5 range. Many of the charts that show nutrient uptake at different pH levels are different but when you're getting < 5.5 or> 6.2, nutrient uptake reduces significantly. Those swings just make it harder for your plant to get the chemicals that it needs.

 

[bluter]

You might want to get your head around VPD. A lot of growers proudly state that they don't care or believe in VPD which is unfortunate since plants live and die by it. This may well be what you're running into.

you grow within it even if you don't believe in it.

 

[bluter]

until I figured out "When you hit 64, it's sometimes hard to pee." As men in our "late 50's", you, bluter, and I will understand that little nugget of wisdom. ;-)

errr well, a fish and chips plus 3 pints in at the pub, and it gets hard to turn the taps off if going further ..


i do band and show production as a lighting tech. i have a few pre-programmed things all set up if i need to go for a walk during a show ...

 

[ulysees]

Air temp is in the 60's and that RH are brutal on a plant. Check the VPD chart below. Your grow is running at 0.6 which is wetter than it should be for germination.

At those temps growth will be very slow and the relatively high RH makes it very hard for the plants to transpire. It's like a cold, wet blanket sitting on the leaves. Since they are having a hard time releasing water, they're having a hard time taking up water. That can lead to nutrient imbalances if you don't adjust your EC.

You might want to get your head around VPD. A lot of growers proudly state that they don't care or believe in VPD which is unfortunate since plants live and die by it. This may well be what you're running into.

What's light are you using and what's your dimmer setting? I strongly recommend that growers spend $32 for a light meter that will "remove all doubt" when it comes to light levels.

What's your water temp? As temperature falls, dissolved oxygen goes up but as temp continues to drop, you can have problems with nutrient imbalances. I had the hardest time remembering which chemical stopped being taken up at 64° until I figured out "When you hit 64, it's sometimes hard to pee." As men in our "late 50's", you, bluter, and I will understand that little nugget of wisdom. ;-)

pH ranging from 5 to 7? Wow, that's a very wide range and the swings just mean that there's more time when nutes are not avaiable to the plant. The "optimal" level is 5.8 but a lot of growers do fine in the 5.5 to 6.5 range. Many of the charts that show nutrient uptake at different pH levels are different but when you're getting < 5.5 or> 6.2, nutrient uptake reduces significantly. Those swings just make it harder for your plant to get the chemicals that it needs.

errr well, a fish and chips plus 3 pints in at the pub, and it gets hard to turn the taps off if going further ..


i do band and show production as a lighting tech. i have a few pre-programmed things all set up if i need to go for a walk during a show ...

I understand the PH problem, that's one reason I switched to the Advanced Nutrients. I'm still getting a feel for how to work with it but it seems to keep the ph a lot more stable, but it's also harder to get it to move if it's not where you want it. As far as humidity and temp are concerned average temp in my basement is always around 65F or so, varies very little. I've grown in humidity as low as 25% and as high as 60%, depending on the season(drier in the winter)and whether I ran a humidifier or not.
So you think my problem is humidity and temp? Makes sense, considering that I've tried everything else. I've seen the chart you posted and I've read about VPD before. Is weed particularly sensitive to this? I ask because I also have garden vegetables growing the same environment and they're doing great. I have a humidifier running now because otherwise, like I said, the humidity would be in the 20's. It's basic, just on or off, so I can't regulate to a specific humidity. I hadn't thought about the water temp, an aquarium heater could solve that problem. I don't have a lot of money for equipment, I improvise and build everything I use. I'll pick up a heater to warm the water and turn the humidifier off.
Thanks for the response.

 

[Keffka]

I understand the PH problem, that's one reason I switched to the Advanced Nutrients. I'm still getting a feel for how to work with it but it seems to keep the ph a lot more stable, but it's also harder to get it to move if it's not where you want it. As far as humidity and temp are concerned average temp in my basement is always around 65F or so, varies very little. I've grown in humidity as low as 25% and as high as 60%, depending on the season(drier in the winter)and whether I ran a humidifier or not.
So you think my problem is humidity and temp? Makes sense, considering that I've tried everything else. I've seen the chart you posted and I've read about VPD before. Is weed particularly sensitive to this? I ask because I also have garden vegetables growing the same environment and they're doing great. I have a humidifier running now because otherwise, like I said, the humidity would be in the 20's. It's basic, just on or off, so I can't regulate to a specific humidity. I hadn't thought about the water temp, an aquarium heater could solve that problem. I don't have a lot of money for equipment, I improvise and build everything I use. I'll pick up a heater to warm the water and turn the humidifier off.
Thanks for the response.

Temps can make a very big difference. Many nutrients become exceedingly difficult for the plant to take up as the temps drop. They are quite literally freezing in place. If you put humidity problems on top of low temps then you’re essentially suffocating the plant while freezing its root zone. This is why you see so many conflicting issues, the elements are having a difficult time moving out of the medium.

I don’t run hydro but I imagine this becomes an even bigger issue since you don’t have the buffer that soil gives

 

[Keffka]

Also if you’re picking up a heater, you need to decide which type. The electric forced air types of heaters will drastically reduce your rh, almost as much as a dehumidifier itself. The oil filled radiator types that don’t force air will not have as drastic of an effect on your rh but will need to be larger to be comparable to the forced air. Make sure you take that into account when deciding

 

[SmokingWings]

I'm still getting a feel for how to work with it but it seems to keep the ph a lot more stable, but it's also harder to get it to move if it's not where you want it.

I do not grow in hydro but I am fascinated by the method. I had looked up some info on this pH Perfect on the companies web site. Near as I can figure it out the grower does not try to get any pH reading to move no matter how far off it might look. Just leave it alone no matter what.

Something to do with how each nutrient molecule is deliberately chelated or bonded to a particular metallic ion molecule which controls when each nutrient is released. The pH itself is controlled by the process and deliberately will swing up and down and maybe even get out of range for awhile. Those times when the pH reading is where you do not want it is beside the point. That is where the process says it is supposed to be in order for the sytem to control the release of the nutrients.

I get the feeling that any attempt at trying to control the pH reading actually slows down the breaking of the bonds or chelates and is affecting the release of particular nutrients and the amounts. At the same time other nutrients might be being released too fast and therefore in too large of an amount. And some nutrients might not be being released at all.

 

[ulysees]

I do not grow in hydro but I am fascinated by the method. I had looked up some info on this pH Perfect on the companies web site. Near as I can figure it out the grower does not try to get any pH reading to move no matter how far off it might look. Just leave it alone no matter what.

Something to do with how each nutrient molecule is deliberately chelated or bonded to a particular metallic ion molecule which controls when each nutrient is released. The pH itself is controlled by the process and deliberately will swing up and down and maybe even get out of range for awhile. Those times when the pH reading is where you do not want it is beside the point. That is where the process says it is supposed to be in order for the sytem to control the release of the nutrients.

I get the feeling that any attempt at trying to control the pH reading actually slows down the breaking of the bonds or chelates and is affecting the release of particular nutrients and the amounts. At the same time other nutrients might be being released too fast and therefore in too large of an amount. And some nutrients might not be being released at all.

Well, it would certainly be easier to just leave it alone. I didn't read much past the advertising blurb, I'd had so much difficulty with the Flora I was just ready to do something else. Everything I ever read has been so adamant about keeping it 5.5 to 6.5 it seemed like that was the gospel. I'll give it a try, just monitor for a while and not try to change it. It's at 5.5 right now, which is on the low side, blocking magnesium and calcium. I almost never tried to raise it, even with the Flora nutrients because it would always come up on it's own. Thanks for the tip.

 

[ulysees]

Also if you’re picking up a heater, you need to decide which type. The electric forced air types of heaters will drastically reduce your rh, almost as much as a dehumidifier itself. The oil filled radiator types that don’t force air will not have as drastic of an effect on your rh but will need to be larger to be comparable to the forced air. Make sure you take that into account when deciding

Air temp in the basement is around 64 to 66 year round. If I need more heat I can just open a vent from the central heat in the house. Humidity swings wildly though, winter time in the 20's, summer I have to run a dehumidifier to get it below 68%. Just checked my water temp as someone else suggested, water was 58F. I would have thought it would be room temp after a day or two at least. Put an aquarium heater in there to bring that up. Was running a humidifer, shut that off, humidity is down to 52% so far.

 

[bluter]

Well, it would certainly be easier to just leave it alone. I didn't read much past the advertising blurb, I'd had so much difficulty with the Flora I was just ready to do something else. Everything I ever read has been so adamant about keeping it 5.5 to 6.5 it seemed like that was the gospel. I'll give it a try, just monitor for a while and not try to change it. It's at 5.5 right now, which is on the low side, blocking magnesium and calcium. I almost never tried to raise it, even with the Flora nutrients because it would always come up on it's own. Thanks for the tip.

as was mentioned earlier you don't change or adjust ph with the ph perfect line. it only makes things worse.

 

[Delps8]

errr well, a fish and chips plus 3 pints in at the pub, and it gets hard to turn the taps off if going further ..


i do band and show production as a lighting tech. i have a few pre-programmed things all set up if i need to go for a walk during a show ...

Technology to the rescue!

 

[Delps8]

Temps can make a very big difference. Many nutrients become exceedingly difficult for the plant to take up as the temps drop. They are quite literally freezing in place. If you put humidity problems on top of low temps then you’re essentially suffocating the plant while freezing its root zone. This is why you see so many conflicting issues, the elements are having a difficult time moving out of the medium.

I don’t run hydro but I imagine this becomes an even bigger issue since you don’t have the buffer that soil gives

With DWC/ RDWC, there's a bucket or res full of cold water that should be <70°. So it will tend to drop air temp.

At 64°, P is not/starts to not be taken up. 64° damned cold.

 

[Delps8]

Also if you’re picking up a heater, you need to decide which type. The electric forced air types of heaters will drastically reduce your rh, almost as much as a dehumidifier itself. The oil filled radiator types that don’t force air will not have as drastic of an effect on your rh but will need to be larger to be comparable to the forced air. Make sure you take that into account when deciding

I've tried the little oil heater, a "panel" type heater, and, just recently, settled on the AC Infinity heater which is forced air.

They all have their pros and cons but the latter gets my nod because it's dynamic, it's controlled by the Controller 69, and because it will tend to drop RH.

 

[Delps8]

I understand the PH problem, that's one reason I switched to the Advanced Nutrients. I'm still getting a feel for how to work with it but it seems to keep the ph a lot more stable, but it's also harder to get it to move if it's not where you want it.

I understand the attraction to AN and, after the insanity that I hit chasing pH when I started growing, I was very tempted to go that route. If it works, great but if it doesn't work, you're sort of locked out, so to speak.

As far as humidity and temp are concerned average temp in my basement is always around 65F or so, varies very little. I've grown in humidity as low as 25% and as high as 60%, depending on the season(drier in the winter)and whether I ran a humidifier or not.
So you think my problem is humidity and temp? Makes sense, considering that I've tried everything else. I've seen the chart you posted and I've read about VPD before. Is weed particularly sensitive to this? I ask because I also have garden vegetables growing the same environment and they're doing great. I have a humidifier running now because otherwise, like I said, the humidity would be in the 20's. It's basic, just on or off, so I can't regulate to a specific humidity. I hadn't thought about the water temp, an aquarium heater could solve that problem. I don't have a lot of money for equipment, I improvise and build everything I use. I'll pick up a heater to warm the water and turn the humidifier off.
Thanks for the response.

Is weed particularly sensitive to this?
My sense is that cannabis is a pretty tough plant but I have zero experience growing anything else. Look at the range of temp and RH that you're growing in. It's all over the place and yet they live and thrive, hopefully.

 

[Keffka]

I've tried the little oil heater, a "panel" type heater, and, just recently, settled on the AC Infinity heater which is forced air.

They all have their pros and cons but the latter gets my nod because it's dynamic, it's controlled by the Controller 69, and because it will tend to drop RH.

I also prefer the forced air. It allows for greater, and quicker control of the temperature while handling rh very efficiently. More airflow is rarely a bad thing as well. It can get pricey to run depending on your environment and season, but it’s well worth the cost for the level of control.

 

[ulysees]

With DWC/ RDWC, there's a bucket or res full of cold water that should be <70°. So it will tend to drop air temp.

At 64°, P is not/starts to not be taken up. 64° damned cold.

I keep an aquarium so I had a spare heater handy. I've got the temp up to 70. And all this tracks because I've had trouble all along with potassium deficiency. Humidity down, water and air temp up.