Deep ridges in seedling leaves

[Dayzt]

My 1 week, 4 day-old seedlings look pretty healthy, but i'm worried about some deep ridges showing on the first and second set of leaves. They also seem to be growing slow. Considering the age of them and the look, can I get some comments and/or suggestions?

Pic #1 - Closeup of Deb - Notice deep ridges and strange leaf growth. Not worried about the coteyedons turning yellow...

Pic#2 - Another closeup of Deb

Pic#3 - Overall look at all 6 seedlings just after watering - alot of them have the deep ridges... the excess water was cleaned up afterwards - not left standing in water.

[Indica Kid]

Temperature stress or salt build up are typical causes of deep ridges. I'm guessing if your soil is brand new salt build up isn't the problem. What kind of light are you using and how close is it?

[Dayzt]

I have them under a 400w MH. I've been moving the light alot in their short lifespan - still looking for that sweet-spot that they are most comfortable with... it's tricky with the big light at such an early stage as this. Do the ridges appear due to high temps or low temps? ...or just a large variance between the two?

Most of the time i'd say the light is about 16 - 24" away from the plants... I tried moving it closer but the promix dries out extremely fast in the small peat-moss cups because the lighty has no cover. I'd like to move the light up more to alleviate the high temps, but I at the same time, I don't want to have them stretch any more than they already did... I've since put a small fan on one end of the light, blowing laterally at the bulb... not sure if that helps - seems to still be at the same temperature down by the plants. Temps are generally 28-29 degrees celcius when the light is on, and as low as 19-20 degrees celcius when it's off.... I also have a cool-mist humidifier running constantly and the bathroom ceiling fan running constantly....

Thanks for the help!!!

[Indica Kid]

Typically high temperatures coupled with salt buildup cause ridges to form. I cant see anything wrong with your setup and assuming your soil is brand new I cant see anything that would be causing the ridges. It's possible your strain just has big ridges, typically if big ridges are occurring because of heat stress/salt buildup the leaves will also be stretching upwards which yours aren't doing.

[Gr33n_Cr0nIc]

All your plants will look like they are stretching but it isnt. usually all types will get about 1-3 inch stems when young.... lucky for you your using soil... what i have found in using soil is that when u build up dirt around the stem it will start to build roots from the stem that is now in dirt. so it looks like you have some room in that pot to put more soil...

as for the MH... that thing gives off alot of heat.. so keep it far away till they are like 3 weeks old and can handle a little more heat

[Dayzt]

Awesome - thanks for all the comments and suggestions guys! It really is invaluable, as I wouldn't really know what to do for sure with these results so far!

Indica Kid - Good to know - I'll stop worrying about the ridges at this point then and be thankful that I have healthy plants!

Gr33n - That's great to hear - I know it's easy to point a finger at the common 'stretching' issue, especially at this stage. I'll try moving the light a bit further away and monitor them for results. I'll be repotting them all tonight so wish me luck!

...thanks again guys!