Lanky Stems - Puzzled with light!

[Nartak]

Hey people,today my babies are on day six and the tallest one has already hit 8cm and the smallest is 6cm,i have the light (600w MH) at about 65cm from the pots and im already worried about lightburn.
My temps are between 27-29 lights on and 18-19 lights off.Exhaust fan is on with the lights and dry fan is hitting the MH/Reflector to cool down heat over the plants.With a humidity @ 30-45% am i ok to reach 29C (given i don't see lightburn)? I also have a CO2 bag but my ppm counter has broken and i can't measure...

With bright grow lights (such as 600W HPS and brighter), cannabis plants of all stages can thrive at slightly higher temps up to a max of about 85°F (30°C) even with no CO2 enrichment, as long as there is low relative humidity and plenty of air movement.

 

[Royal Nugs]

I think you'll be fine but you're definitely on the cusp. Please keep in mind that thermometer placement can drastically effect your temperature readings. The thermometer should not be placed in direct light. I use a $20 infrared thermometer to read leaf surface themperature. I think it's the most accurate representation of temperature.

Also, I'm assuming you're going HPS for flower? I ask because they get hotter than MH.

 

[Nartak]

Temp i control with the dry fan hitting directly on the bulb,i can stay at 28-29 lights on( i will prolly add another dry fan for flower to get 26C)..I was worried about the stretch so i just moved the whole room 30 cm towards the ballast and lowered the MH to 48cm above seedlings it was at 67 something,sorry...I will post pictures after i walk the dog and you can tell me if thats bleaching or if im just panicking lol!!

Yes will be doing HPS for flower..Im risking infections by letting the zip be open a bit on the top and the velcro open on the side but Church is rot tested and can hold its ground against it,also there's not much mites in winter time here,it's cold enough for them to die..

 

[insomniaczzz]

You didn't mention what medium you are growing in. Are they in solo cups? If so, I would, if you have room, top off the cups with more soil to cover up some of that long lanky stem. Also, I didn't see you mention this) have a light breeze blowing directly on the wee ones. It will go a long way toward strengthening those delicate stems.

 

[Nartak]

Ive got a journal here that explains everything insomniac,sorry i thought i had seen you on there..Im growing in clay pebbles but the seedlings were started in cubes.They are already in the pebbles due to their rapid taproot lengthening (about 4-5 cm each on day 4 after seed planted)

 

[Nartak]

No Title

These i took 10 mins ago,do they look ok? They look like they're tinting yellowish in the middle of the leafs..They've also turned towards the MH after i took her down to 48cm distance so i turned the pots around to fix their angle,a dry fan is blowing on them lightly however,will have a bigger one in a couple days!!

About the temp,the meter itself says 31C for [IN] temperature which is inside the meter or closest to it,then it has a second reading which reads [OUT] and that is where the connected metal rod is placed(right next to the plants stem) and that says 27-28C..

 

[insomniaczzz]

Oops, I'm bad. I do remember your other thread. Didn't associate. thanks for letting me know.

 

[insomniaczzz]

To me they look fine. Karlee is one of our resident hydro grow pros. Maybe she'll stop in and give you an opinion.

 

[Nartak]

Hope she does see your tag,im worried bout my babies,obviously a tad more than needed but im sure they're taller than they should be,i'll get them 2-3 cm pebbles in there,luckily have some left!Still that leaves me with 5-7cm (if they grow next night time like they did through this one) stems and only 2 leafs...Is that a biggie?

 

[Nartak]

So many gardens,so little time