Vpd struggles.. Whats wrong with this leaf?

[Dabward]

I've been trying to dial in VPD for the first time. And ive been struggling .. they sprouted 6 days ago. A Northern lights autoflowet sprouted first.. but I had the VPD low . .4-.6 and the temp lower 69ish. Why? I don't know.. The other 3 were sprouting slowly. So I turned the heat up to 75 and kept vpd between. 4&.8 and the other 3 started going strong. And after the first spiked leaves started showing up I turned vpd up to .8-1 But the NL slowed its grow. The other 3 are a node ahead now.. So last night I tried dropping vpd back down to .5-.8 NL AF sprouted another node. But then this Green Crack here it has creases in the leaves.. Im not sure what the creases are. Could be large range of humidity over 24hrs.. green crack is not an auto.. and they are all in the ocean soil the blue bag. Too early to be cal mag or nutrient anything.. Temps been consistently been between 73 and 75. I'm struggling to get humidity stable period. I typically have a 10% bounce over the course of an hr. Which is prob too much.. Any guidance is appreciated!

 

[gashouse]

wow!!! u got all those fancy sensors and such and still cant get seedlings growing good? should have spent some of that sensor money on a grow guide...its wayyyy too early to be worrying with VPD anyway. crawl before u run a marathon

 

[Dabward]

wow!!! u got all those fancy sensors and such and still cant get seedlings growing good? should have spent some of that sensor money on a grow guide...its wayyyy too early to be worrying with VPD anyway. crawl before u run a marathon

Thanks for the helpful information. I will certainly take that into advisement. Not like I've read the Cervantes Bible and Rosenthal guide circa 17. I've had plenty of great grows before. I've just been fixated on the VPD and ignoring my experience driven instincts. I did just read an excellent post from aqua man that helped me to better understand what I'm looking at. But again. Thank you for your positive knowledge based feedback.

 

[Nate_in_AK]

It seems possible to me that the different strains prefer different environments, but also seems too early in their life for VPD to be much of a factor? When they are that young I'm focused on not over watering or under watering them. I wonder if at this age the differences you are seeing are just genetic stuff? Cool to see you getting techy with it.

 

[FourthCity]

I've been trying to dial in VPD for the first time. And ive been struggling .. they sprouted 6 days ago. A Northern lights autoflowet sprouted first.. but I had the VPD low . .4-.6 and the temp lower 69ish. Why? I don't know.. The other 3 were sprouting slowly. So I turned the heat up to 75 and kept vpd between. 4&.8 and the other 3 started going strong. And after the first spiked leaves started showing up I turned vpd up to .8-1 But the NL slowed its grow. The other 3 are a node ahead now.. So last night I tried dropping vpd back down to .5-.8 NL AF sprouted another node. But then this Green Crack here it has creases in the leaves.. Im not sure what the creases are. Could be large range of humidity over 24hrs.. green crack is not an auto.. and they are all in the ocean soil the blue bag. Too early to be cal mag or nutrient anything.. Temps been consistently been between 73 and 75. I'm struggling to get humidity stable period. I typically have a 10% bounce over the course of an hr. Which is prob too much.. Any guidance is appreciated!

The plants are too small to get accurate readings for vpd. With your temps and rh where they are everything is probably fine, plants look good. The app you are using for vpd doesn't look like it will be useful, I have seen very few vpd apps or devices that take leaf temps into account, without knowing leaf temps you can not accurately calculate vpd.

 

[Dabward]

wow!!! u got all those fancy sensors and such and still cant get seedlings growing good? should have spent some of that sensor money on a grow guide...its wayyyy too early to be worrying with VPD anyway. crawl before u run

The plants are too small to get accurate readings for vpd. With your temps and rh where they are everything is probably fine, plants look good. The app you are using for vpd doesn't look like it will be useful, I have seen very few vpd apps or devices that take leaf temps into account, without knowing leaf temps you can not accurately calculate vpd.

This app with the iponic 624 controller does have a spot to enter leaf temp for an accurate vpd. That is with the leaf temp entered. You might be right about accuracy tho. With the IR laser on the leaf it's a typically .1 or .2° different. Right now it's 75.7 sensors are right at plant height. And gun says 75.9 . Considering I dropped the seeds in a cup of water last Saturday. They sunk by the afternoon. In paper towels and sprung tap roots by Sunday morning. Put them in soil sunday afternoon. And 1 week later I think overall I'm doing solid. I'm acting like a helicopter parent.. like it's my first grow. I need to chilllll

 

[AdrienneGC]

I've been trying to dial in VPD for the first time. And ive been struggling .. they sprouted 6 days ago. A Northern lights autoflowet sprouted first.. but I had the VPD low . .4-.6 and the temp lower 69ish. Why? I don't know.. The other 3 were sprouting slowly. So I turned the heat up to 75 and kept vpd between. 4&.8 and the other 3 started going strong. And after the first spiked leaves started showing up I turned vpd up to .8-1 But the NL slowed its grow. The other 3 are a node ahead now.. So last night I tried dropping vpd back down to .5-.8 NL AF sprouted another node. But then this Green Crack here it has creases in the leaves.. Im not sure what the creases are. Could be large range of humidity over 24hrs.. green crack is not an auto.. and they are all in the ocean soil the blue bag. Too early to be cal mag or nutrient anything.. Temps been consistently been between 73 and 75. I'm struggling to get humidity stable period. I typically have a 10% bounce over the course of an hr. Which is prob too much.. Any guidance is appreciated!

Looks like you have plenty of sensors and calculations but just in case, here is a VPD calculator that may help.