Drooping cotyledons on first grow

[Sooperdooper]

Hello, this is my first grow, I'm into the second day since the seeds sprouted. I'm noticing 2 of the 3 plants that have shot above the surface have droopy cotyledons and I'm not sure if it's a sign of a problem and how to correct it.
The temperature stays right around 73.5 F consistently with a humidity a bit over 60 percent. I have a 400w hps bulb and I just added a Co2 bag (is it too early?)
The seeds are green gelato auto and fat banana auto.
Any help would be appreciated

 

[Hydroholic]

Leaves Looks normal. Way to early for the co2, especially with your temps lower.

 

[Sooperdooper]

What temps are reasonable for Co2, and when would you start it? Thanks for the response

 

[Anthony Suszko]

I just sprouted some Afghani and my seedlings looked very much like this before perking up after a couple days... These plant photos look like they are about 24-48 hours after shedding the seed casing. The only thing that throws up a red flag for me is Temp..73.5 feels a little cold not accounting for sleep cycle temp drop which could drop 5 degrees or so. Source Grow Weed Easy, Temp scale for Veg/Flow- Vegetative -70-85 °F - Flowering 65-80°F . I'm running 78'-80' sort of in the middle of that vegetative temp scale and plants respond well to it..

 

[Sativa1970]

Cotyledons leaves are not that photo active.Just gets the plant a little boost to help make the true leaves.They will yellow and fall off before you know it. If you are at the top end of Anthonys temp scale or just over, that is the CO2 range.Everyone has there opinion on CO2 but until it is mature (around 4 nodes) you won't get any real return from adding it. When you switch light schedule and add intensity your lights, temp will climb and CO2 will have the biggest impact.

 

[013]

It’s just a co2 bag right? Totally passive so it’s not like he’s got an open valve on co2 tank burning cash. Some bags take a period of time (30 days etc) to activate the ingredients so read the directions.

 

[Sooperdooper]

Thanks everyone for the responses, the plants have continued to grow, although the one with the big curl is going slower (don't know if it's cuz that one's indica) but they are all still moving so I'm hopeful it'll work out. I'll seal up the Co2 bag for the time being