Lights out, high humidity, calcium deficiency, Question?

Buba Blend

Well-Known Member
I read this in growweedeasy:

These things can trigger what appear to be Cal-Mag deficiencies - fix the problem and many deficiencies will go away...
Overwatering & underwatering
High humidity
Uneven moisture levels in the soil or growing medium
Too-high levels of N-P-K nutrients
PH is too high or low

I have a good environment during lights on in my grow room with the door open. lights out I close the door to my grow room 10x10 and leave one circulating fan on and also the inline fan that pulls air through the charcoal filter and the lights.
The humidity climbs to 80-85% overnight. Temps are about 71 for a low temp.

Is letting the humidity climb to 80+ overnight creating problems? I know it's not good for the charcoal filter. I should probably fix it. Was wondering if its hurting the quality of my flowers.
I'm dealing with what I believe is a calcium deficiency that started at 3 weeks into flowering, I'm 5 weeks into flowering now, no big deal, its only on a few plants and it seems to be under control.
Is it possible that I might have avoided a calcium deficiency if I controlled the night time humidity?
Thanks in advance.
 

GroErr

Well-Known Member
While it won't hurt (high RH) your growth, you're definitely in the range where mould or PM can cause you problems in flowering. I'd suggest looking at adding a dehumidifier, you can set it to say 50-55% and put it on a timer so it comes on only through lights-out and maintains the RH in a more reasonable range. You can also try bringing in drier air if that's an option for you.
 

Buba Blend

Well-Known Member
While it won't hurt (high RH) your growth, you're definitely in the range where mould or PM can cause you problems in flowering. I'd suggest looking at adding a dehumidifier, you can set it to say 50-55% and put it on a timer so it comes on only through lights-out and maintains the RH in a more reasonable range. You can also try bringing in drier air if that's an option for you.
Thanks! I'm fortunate, I had PM on a couple of leaves a few years ago but was able to remove them in veg and had no other problems with it spreading. I've never had a mold problem living in the desert. I'm gonna get a dehumidifier.
 

ktmac20

Well-Known Member
While it won't hurt (high RH) your growth, you're definitely in the range where mould or PM can cause you problems in flowering. I'd suggest looking at adding a dehumidifier, you can set it to say 50-55% and put it on a timer so it comes on only through lights-out and maintains the RH in a more reasonable range. You can also try bringing in drier air if that's an option for you.
I agree and couldn't have responded with anything different

Cheers
 

Buba Blend

Well-Known Member
Pretty much what they said ^^^^^

I would add that if you supplied pics of the plant and the areas showing the problem.....It's rather easy to see why and if it's a "masked/false" Ca symptom/cause.

Take a look here for a "kinda" related thread.

https://www.rollitup.org/t/check-the-plant.924954/#post-13089882
Here are some pics. Included a pic of the bottom leaves. 1st sighting of the def was at 3 weeks 2 days into flowering. These pics are at 5 weeks 1 day.
3 of 6 plants from the same seeds have no calcium def.
They are in soil and will finish flowering between 9-11 weeks.

A.JPG B.JPG C.JPG D.JPG E.JPG
 

Buba Blend

Well-Known Member
keep all your circulating fans on at night, make sure you have air moving on all your buds, water when the lights come on then your pots wont be wet during lights out, what are you ph ing at ?
I use one part tap 4 parts RO (150ppms) My water normally tests at 8. If its above 7 I ph down to 7. If when I add nutes if it drops below 6 I ph up to 6.
 
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Dr. Who

Well-Known Member
Hmm....Ph is an issue, along with a blocking problem. It's low....and locking out Ca.

What nutrient and supplements are you using?
If it's more then one thing (supplements included), how are you mixing them? describe that in detail please......Looks like a nutrient block is part of this!

Simply water with plain water (RO and drop the tap as something maybe in that tap we don't know about) with a good Ca/mg product. pH to 6.7 at every watering - for 7-10 days and restart nutrient at a lower rate. Say around 66% (2/3 of what your feeding now)!
BE SURE you let the pot dry out more between watering.....very important!
 

Buba Blend

Well-Known Member
Hmm....Ph is an issue, along with a blocking problem. It's low....and locking out Ca.

What nutrient and supplements are you using?
If it's more then one thing (supplements included), how are you mixing them? describe that in detail please......Looks like a nutrient block is part of this!

Simply water with plain water (RO and drop the tap as something maybe in that tap we don't know about) with a good Ca/mg product. pH to 6.7 at every watering - for 7-10 days and restart nutrient at a lower rate. Say around 66% (2/3 of what your feeding now)!
BE SURE you let the pot dry out more between watering.....very important!
Thanks!
3 Gal plastic pots FFOF soil. Watering was every 2 or 3 days at the start. 1 part tap (sitting for 24hrs) / 4 parts ro 150ppms. Added 3 tbsp per pot dolomite lime to top soil on day 14 in FFOF. Day 19 1st fertilizer with FF Big Bloom 2 tbls/gal + GO Cal/mag 3 tsp / 5 Gallons. I'd usually wait longer to fertilize the 1st time, but ran into the same calcium thing last grow and wanted to give them a boost. I started supplementing every other feeding after day 19 in ffof with 3 tsp GO cal mag in 5 gal of water. Big Bloom is usually every 3rd watering. At about 19 days in FFOF I started watering every day, they were drinking about a half gallon of water every day until about 1 week into flowering when they started drinking less so I backed down to every other day.
I wanted to give them a boost by giving them 1 tsp / gallon of Tiger bloom at 1 week into flowering, 3 weeks into flowering and the final time at 4 weeks and 4 days (1 1/2 tsp/ gal the 3rd time.)
At 3 weeks 2 days into flower after spotting the necrotic spots I added 3 tbsp gypsum per pot to the top soil. I think they liked it because the leaves lifted to the light within 24 hours as if to pray even at lights out. I always thought it a good sign when they do this.

At 4 weeks and 6 days bat guano feeding (0-5-0) a little less than a tbsp per pot.
At 5 weeks flowering I gave epson salt dissolved 1 TBSP per gallon of water to the 3 plants with the calcium problems. All 6 plants received the same feedings described above aside from the epsom salt. 3 of the 6 show no calcium deficiency.

That's where I'm at, not sure if I created any chaos.

If mixing nutes I will add GO Cal Mag to water mix well, then add Big bloom. I may have reversed the order. No nutes mixed with Tiger Bloom. No nutes mixed with Epsom salt.

Also last grow when I ran into the problem I was watering much less often, someone suggested I try watering more often this grow, this is the 1st grow in a long time where I went through a phase of watering every day as described above.
Thanks Again!
 
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Dr. Who

Well-Known Member
Hmm. Points to a too damp - low pH problem.......3 gallon pots and 8 cups of water a day is the problem point...

I am an everyday watering guy. In 3 Gal pots during veg.....depending on plant size and uptake.....I might reach 750ml at lights on (6 cups) for the day. At peak uptake in bloom, on my biggest plants in 7 gallon pots. I never reach 8 cups (2000 ml or 2 liters) per day!
IF I get a dry plant "droop", it's because I was delayed a cpl of hrs past 24 in watering. A bit of a droop is not "bad" and is far better then over watering!

In 5 gal pots with 5'-5.5' plants in full bloom. I use 1000ml (1 liter or 4 cups) of water on a 24 hr basis. Temps, RH and airflow are factors that can shift amounts used either up or down....
In veg that amount starts low and increases as the plant does.

The idea of daily watering is to have the soil dry out to almost the point of the plant "drooping" by lack of moisture to uptake! This provides more O2 to the roots and that is a GOOD thing! Same with the pH swing and it's relation to nutrient uptake. You also have the ability to adjust as needed, anything you need more/less of to make a "correction". The plant reacts faster to these changes too.

The use of synthetic daily feeding is is based on a low NPK value in the feed....When I did it. my NPK values were 2.8-2.2-3 in veg and at the flip it made a MINOR shift to 3.4-2.6-3.5 At week 4 I began adding a 0-7-5 PK boost with a 0-0-3 K kicker....The boost and the kicker were done every other day...till week 5-6 (strain dependent) and then every day for 2 weeks. Back to "normal" but for the booster being done every other again. I would drop the boost about a week before harvest
 
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zem

Well-Known Member
Buba, I think that you are having the same issues as i am. I figured out that it was never Ca deficiency in the first place, Ca deficiency begins in the younger upper leaves, but my issue begins on the bigger older fan leaves. The purple stems signify phosphorus deficiency, and the spots K deficiency. Hope this helps
 

Gquebed

Well-Known Member
What kind of air circulation do you have going? As in how are they getting fresh air? Are you exhausting the space and if so where to?

The reason i ask is because the problem may be as simple as the plant is being choked out from lack of fresh air...or rather the co2 in the air. That looks just the same as lockout from ph probs so rule that out first before chasing down ph problems....or you will be running around in circles.

And from what you described about your setup i would be willing to bet lack of fresh air is your problem.

Ask me how i know. Lol
 

Buba Blend

Well-Known Member
Hmm. Points to a too damp - low pH problem.......3 gallon pots and 8 cups of water a day is the problem point...

I am an everyday watering guy. In 3 Gal pots during veg.....depending on plant size and uptake.....I might reach 750ml at lights on (6 cups) for the day. At peak uptake in bloom, on my biggest plants in 7 gallon pots. I never reach 8 cups (2000 ml or 2 liters) per day!
IF I get a dry plant "droop", it's because I was delayed a cpl of hrs past 24 in watering. A bit of a droop is not "bad" and is far better then over watering!

In 5 gal pots with 5'-5.5' plants in full bloom. I use 1000ml (1 liter or 4 cups) of water on a 24 hr basis. Temps, RH and airflow are factors that can shift amounts used either up or down....
In veg that amount starts low and increases as the plant does.

The idea of daily watering is to have the soil dry out to almost the point of the plant "drooping" by lack of moisture to uptake! This provides more O2 to the roots and that is a GOOD thing! Same with the pH swing and it's relation to nutrient uptake. You also have the ability to adjust as needed, anything you need more/less of to make a "correction". The plant reacts faster to these changes too.

The use of synthetic daily feeding is is based on a low NPK value in the feed....When I did it. my NPK values were 2.8-2.2-3 in veg and at the flip it made a MINOR shift to 3.4-2.6-3.5 At week 4 I began adding a 0-7-5 PK boost with a 0-0-3 K kicker....The boost and the kicker were done every other day...till week 5-6 (strain dependent) and then every day for 2 weeks. Back to "normal" but for the booster being done every other again. I would drop the boost about a week before harvest

Thanks Dr. Who. I was going to ask about watering 6 cups a day during the short span they were drinking 8 cups every day.
Then I read a post you wrote to someone else Sunday that I think answered my question.


(Dr Who. Sunday Post : I find run off in soil plants as being counter productive! If you have to do a water to run off - your over feeding.)


I always tried to get them to run off some water because I was afraid of leaving dry pockets in the soil and because I read I should have 10% run off, not sure if I read it in books or on RIU. I'll have to absorb what I read in your post and I will experiment with my watering methods.

On a separate note. In the past I never flushed my soil near the end of the grow. It was probably on RIU that I read about flushing and did it for 3 grows. You played a large part in teaching me to not flush again. I think I noticed my flowers not finishing as well when I flushed, of course my plants not finishing well during those 3 grows could have been for other reasons also.



Buba, I think that you are having the same issues as i am. I figured out that it was never Ca deficiency in the first place, Ca deficiency begins in the younger upper leaves, but my issue begins on the bigger older fan leaves. The purple stems signify phosphorus deficiency, and the spots K deficiency. Hope this helps
Thanks. The pictures I took don't do a good job showing the location of the problem. The one fan leaf shown is pretty big and about mid level on the plant and is the lowest leaf with the problem in an early stage. The majority of the deficiency shown is at the upper section of the plant. Note the last picture showing the bottom fan leaves not affected.



What kind of air circulation do you have going? As in how are they getting fresh air? Are you exhausting the space and if so where to?

The reason i ask is because the problem may be as simple as the plant is being choked out from lack of fresh air...or rather the co2 in the air. That looks just the same as lockout from ph probs so rule that out first before chasing down ph problems....or you will be running around in circles.

And from what you described about your setup i would be willing to bet lack of fresh air is your problem.

Ask me how i know. Lol
Interesting. During the day I have four fans. One circulating, one on the ground near the door pushing lower air into the room. One inline fan hooked to two enclosed hoods, another inline hooked to a third hood. The two inline fans exit the room during the day.

Night could be a problem. At lights off I close the room and leave on two of the four fans, no air is vented out of the room at night. I run the circulating one and the inline hooked to the charcoal filter. 8 plants 4-5 foot tall that fill in most of a 5x5 grow area, the room itself is 10x10.
My night time humidity was the concern I had in the 1st post because I seal the room at night. I'm considering getting a de humidifier to bring down the humidity. If it will help my plants to instead vent the air out of my room at night it is definitely a mod I can do.
 

Gquebed

Well-Known Member
Thanks Dr. Who. I was going to ask about watering 6 cups a day during the short span they were drinking 8 cups every day.
Then I read a post you wrote to someone else Sunday that I think answered my question.


(Dr Who. Sunday Post : I find run off in soil plants as being counter productive! If you have to do a water to run off - your over feeding.)


I always tried to get them to run off some water because I was afraid of leaving dry pockets in the soil and because I read I should have 10% run off, not sure if I read it in books or on RIU. I'll have to absorb what I read in your post and I will experiment with my watering methods.

On a separate note. In the past I never flushed my soil near the end of the grow. It was probably on RIU that I read about flushing and did it for 3 grows. You played a large part in teaching me to not flush again. I think I noticed my flowers not finishing as well when I flushed, of course my plants not finishing well during those 3 grows could have been for other reasons also.





Thanks. The pictures I took don't do a good job showing the location of the problem. The one fan leaf shown is pretty big and about mid level on the plant and is the lowest leaf with the problem in an early stage. The majority of the deficiency shown is at the upper section of the plant. Note the last picture showing the bottom fan leaves not affected.





Interesting. During the day I have four fans. One circulating, one on the ground near the door pushing lower air into the room. One inline fan hooked to two enclosed hoods, another inline hooked to a third hood. The two inline fans exit the room during the day.

Night could be a problem. At lights off I close the room and leave on two of the four fans, no air is vented out of the room at night. I run the circulating one and the inline hooked to the charcoal filter. 8 plants 4-5 foot tall that fill in most of a 5x5 grow area, the room itself is 10x10.
My night time humidity was the concern I had in the 1st post because I seal the room at night. I'm considering getting a de humidifier to bring down the humidity. If it will help my plants to instead vent the air out of my room at night it is definitely a mod I can do.

Well if you are exhausting out of the room that would creat neg air pressure and draw fresh air in. With the fans off at night it shouldnt matter as much because the plants transpire less.

where is your exhaust air going? If youre exhaust is just going into the same space that the fresh air is being drawn from then you could have a problem...becuse your exhasut would be drawn back into your grow space.

I did that my first grow...
 

Buba Blend

Well-Known Member
Well if you are exhausting out of the room that would creat neg air pressure and draw fresh air in. With the fans off at night it shouldnt matter as much because the plants transpire less.

where is your exhaust air going? If youre exhaust is just going into the same space that the fresh air is being drawn from then you could have a problem...becuse your exhasut would be drawn back into your grow space.

I did that my first grow...
I have flexible duct that I put outside the door. One is about 3 feet past the floor fan by the door, the other goes in the other direction about 2 feet from the fan on the floor.
I should add, I put the fan there to bring down my temps by pushing the colder air into the room it brought my daytime temps from 81 to 79 degrees. In the winter I keep that fan inside the room not by the door.
 
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Dr. Who

Well-Known Member
Buba, I think that you are having the same issues as i am. I figured out that it was never Ca deficiency in the first place, Ca deficiency begins in the younger upper leaves, but my issue begins on the bigger older fan leaves. The purple stems signify phosphorus deficiency, and the spots K deficiency. Hope this helps
AGREED!
Yet the source problem is from the low pH.....easier to fix, when you know why eh?

Cool?
 

Dr. Who

Well-Known Member
Thanks Dr. Who. I was going to ask about watering 6 cups a day during the short span they were drinking 8 cups every day.
Then I read a post you wrote to someone else Sunday that I think answered my question.


(Dr Who. Sunday Post : I find run off in soil plants as being counter productive! If you have to do a water to run off - your over feeding.)


I always tried to get them to run off some water because I was afraid of leaving dry pockets in the soil and because I read I should have 10% run off, not sure if I read it in books or on RIU. I'll have to absorb what I read in your post and I will experiment with my watering methods.

On a separate note. In the past I never flushed my soil near the end of the grow. It was probably on RIU that I read about flushing and did it for 3 grows. You played a large part in teaching me to not flush again. I think I noticed my flowers not finishing as well when I flushed, of course my plants not finishing well during those 3 grows could have been for other reasons also.





Thanks. The pictures I took don't do a good job showing the location of the problem. The one fan leaf shown is pretty big and about mid level on the plant and is the lowest leaf with the problem in an early stage. The majority of the deficiency shown is at the upper section of the plant. Note the last picture showing the bottom fan leaves not affected.





Interesting. During the day I have four fans. One circulating, one on the ground near the door pushing lower air into the room. One inline fan hooked to two enclosed hoods, another inline hooked to a third hood. The two inline fans exit the room during the day.

Night could be a problem. At lights off I close the room and leave on two of the four fans, no air is vented out of the room at night. I run the circulating one and the inline hooked to the charcoal filter. 8 plants 4-5 foot tall that fill in most of a 5x5 grow area, the room itself is 10x10.
My night time humidity was the concern I had in the 1st post because I seal the room at night. I'm considering getting a de humidifier to bring down the humidity. If it will help my plants to instead vent the air out of my room at night it is definitely a mod I can do.
Yeah, yer over watering at that point still! In 3 gallon pots.....I never went over 4 cups a day - UNLESS I was gassing or the RH was too low! Remember that low RH and higher uptake increase nutrient use too! Another source of "over feeding"...
 

Gquebed

Well-Known Member
I have flexible duct that I put outside the door. One is about 3 feet past the floor fan by the door, the other goes in the other direction about 2 feet from the fan on the floor.
I should add, I put the fan there to bring down my temps by pushing the colder air into the room it brought my daytime temps from 81 to 79 degrees. In the winter I keep that fan inside the room not by the door.
Where is your exhaust going?

Sounds to me like the same room youre drawing fresh air from...

If that is the case then you will likely see more of the necrosis.
 

Buba Blend

Well-Known Member
Where is your exhaust going?

Sounds to me like the same room youre drawing fresh air from...

If that is the case then you will likely see more of the necrosis.
They are in a hall way and the air is likely being sent back into the room with a mix of fresh air. I can extend them further. I'm also considering venting some air from outside at least in the cooler season, summer is a different issue but I usually don't grow in the summer. I think it best I leave them the way they are until I fix my watering issue. That way I'll get a better idea of how my changes effect my grow.
 
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