Heat stress?

[jgoods]

Morning all!

Just a quick one. It looks like heat stress to me but hoping for a second opinion.

Two of my ladies are showing leaves curling up. I have a 250w HPS 60cm * 60cm tent. I have moved the light further away as of yesterday but just wanted to double check my diagnosis was correct?

There have been some mobile nute issues too which you'll see lower down and has happened to all of them with leaves yellowing/dropping. I've just flushed them on Friday so hoping that sorts itself out now.

(It is also pretty cramped in there I know!)

[IceCalibur]

Hi jgoods, tell us what are the temps and humidity inside the tent?

I see you touched upon the feeding issue..you say you flushed, did you suspect overfeeding?

How far along are they?

[IceCalibur]

The yellowing could be a sign of needing a slight increase in feed, unless you're seen evidence of nute burn, like the tips of the leaving turning brown, extremely dark green leaves, clawing etc?

[jgoods]

Switched to flowering 10th March so Day 32 in flowering. Germinated first week of Jan (I lost 2 weeks between end of Feb/March where i stupidly set light to 14/10 instead of 12/12 so they stretched and didnt flower and i had to top them all back down to prevent it becoming a jungle).

I suspected a salt buildup / lock out rather than overfeed as I've been feeding them 1200ppm of Growers Ark Bloom (hard water) and they were still showing signs of being underfed which is why I flushed (havent flushed them previously until now). Looking at them now I'm not seeing any nute burn signs as whilst top is a little bit on the dark side no clawing etc

Humidity has been around 65% normally - I chuck a dehumidifier in there if it goes above that / crank the windows as have had some issues with humidity getting too high. If I'm being honest i think i may have left the dehumidifier in there too much in the last week.

Temps - root zone has been sitting around 16.8C which is a little cooler than I'd like, I've started using a heater but above root zone they sit around 22C.

[IceCalibur]

Switched to flowering 10th March so Day 32 in flowering. Germinated first week of Jan (I lost 2 weeks between end of Feb/March where i stupidly set light to 14/10 instead of 12/12 so they stretched and didnt flower and i had to top them all back down to prevent it becoming a jungle).

I suspected a salt buildup / lock out rather than overfeed as I've been feeding them 1200ppm of Growers Ark Bloom (hard water) and they were still showing signs of being underfed which is why I flushed (havent flushed them previously until now). Looking at them now I'm not seeing any nute burn signs as whilst top is a little bit on the dark side no clawing etc

Humidity has been around 65% normally - I chuck a dehumidifier in there if it goes above that / crank the windows as have had some issues with humidity getting too high. If I'm being honest i think i may have left the dehumidifier in there too much in the last week.

Temps - root zone has been sitting around 16.8C which is a little cooler than I'd like, I've started using a heater but above root zone they sit around 22C.

I'm a little confused mate, so if you suspected them being underfed, why did you flush them?...

We only really flush plants if we suspect a nutrient buildup/overfeeding, or a mix up in feeds/PH etc.

If you're not seeing any signs of nute burn then increase their feed a tadge (not too much), wait and observe the leaves, if they continue to lighten, then continue to increase a tadge, if they darken then stick with it for a while, but continue to keep an eye on.

If temps are 22c, then there is no chance this is heat stress, but I do see the curling/canoeing, so I wonder if the lights were too close at some point, but you've raised them so could have sorted that issue.

You don't have any very powerful fans directly hitting them either right?

[jgoods]

To be honest it could just have been some bad articles I read online. I thought a salt build up was possible over time even without over feeding which is what made me think a flush was needed as the nutrients weren't being absorbed / had a lockout despite a decent concentrate of feed.

Noob error maybe this is my second grow! I'll just gradually up the feed instead

I've only got the one small clip on fan and have that aimed above the canopy rather than at at it to deflect the heat

[IceCalibur]

To be honest it could just have been some bad articles I read online. I thought a salt build up was possible over time even without over feeding which is what made me think a flush was needed as the nutrients weren't being absorbed / had a lockout despite a decent concentrate of feed.

Noob error maybe this is my second grow! I'll just gradually up the feed instead

I've only got the one small clip on fan and have that aimed above the canopy rather than at at it to deflect the heat

Oh it's no problem, we live n learn and I was just confused that's all

Yeah, I'd say she's just a little hungry, so increase slightly and go from there..how long would you say you've got left with these girls?

Doing a great job with them for a second grow

[jgoods]

Oh it's no problem, we live n learn and I was just confused that's all

Yeah, I'd say she's just a little hungry, so increase slightly and go from there..how long would you say you've got left with these girls?

Doing a great job with them for a second grow

No thanks for the help I appreciate it! Always learning.

I'd guess at least 4 weeks left still they're all fattening up and showing no signs of maturing yet, 3 different strains there. I have pineapple express / Bruce banner #3 / kalini Asia so may run into some problems at end with different harvest times but we'll deal with it!

[M_C]

A small amount of heat stress that isn't really worth worrying about... but what you are seeing is where you yoyo'd with the feeding

[jgoods]

Yeah that's a fair point really do need to be more consistent with feeding now. Do you believe in flushing two weeks prior to harvest? Always seems a hotly debated topic