yellow leaves on 2 week old sprout pic..

oh wow. yea temps that high can be the cause. poor lighting too. lights too close. pH levels all out of whack. root rot/stem rot. all kinds of reasons. get those temps down. you also need higher humidity for that kind of heat. cool those plants off. think about what makes you comfortable. are you growing indoors?

 

btw this is what a plant shoulld look like at two weeks

 

Are you refering to the very first two small round leaves at the bottom showing some yellow? If so that is normal and will eventualy die and fall off.

 

yea. after i posted i looked at your pic and couldnt see much yellow.

 

it needs nutes..you started with no nutes and used plain water to water with correct? then it needs nutes ..leaves yellow for lots of reasons yours is a combo of problems..
1 let soil dry out between waterings
2 start with a 1/4 strength veg nutes
it needs nutes now..
pad leaves will yellow and fall of, but a pefectly healthy plant will carry them for quite a while actually..
but it does need nutes..its an auto..auto's feed about 20-30% heaver than reg strains...high outdoor temps and combo of nothing but water(flushing) has made it very hungry..
so its using up nitrogen now at a fast rate and leaves will begin to yellow..
nutes! nutes!

 

Some start giving nutes at about 2 weeks, thats what I did with mine. I also ordered a good PH meter to test the water run off and to see what our tap waters PH is. Nutes are important as it gives the plants the nutrients that they need. Keeping an eye on your PH and keeping it in a good range will also help as I am learning also Nute/water mix will lower the PH. When I check to see if they need watered is I stick my finger in the soil about an inch down and also stick my pinky finger in a few of the bottom drain holes and if it feels dry I water or feed them. I go by water, water then feed routine.

 

NEVER GO BY THE BOOK ! USE IT AS A GUIDE LINE!
if your plant says feed, then feed, and that rule of thumb is for reg strains not auto's..if i even have any kind of strain , and it says feed to me i feed..usualy with a good organic soil mix with organic based nutrients gets them by for the first few week's but its still using nutes..
your soil is dead, no nutes organic and such..so add some..

dude your not listening...flushing is giving your plant nothing but water, you dont have to tell me..lol
i know what it is..exactly what you have been doing..giving it nothing but water...look up flushing..

every time you water with no nutes, your cleaning the soil basicly..get it

 

Those first set of round leaves(cotyleons)are what a young seedling(sprout) lives on for the first week or,so. When they turn yellow(normall) they have used all their nutes and served their purpose.
The plant will use available nutes in the soil DEPENDING on wheather your potting mix has enough nutes to use. In essence the better the soil the more likely it will have enough nutes to feed the plant for +- three weeks.

When leaves turn yellow it is most likely from not enough nutes(nitrogen)or, not enough light for the plant to uptake the nutes.

You don't want to start feeding until the seedling has grown a few sets of leaves. This tells you that the roots are getting established and when you notice pale green or yellowing is a sign it is time to start feeding.

Feed with veg fert at 1/4 strength at first and work up tp 1/2 strength. Use more lights(lumens) if you can for faster growth. Your plant looks ok and just needs a little something to eat to grow.
Auto flowering strains start flowering in three weeks and you will want to change from a veg nute to a flowering nute sometime theirafter.

 

using nutrients too soon is not good because simply tiny plants dont need as much nutrients as adults. waiting 2 weeks or 3 like u are is fine. start weak and then up the dose. those bottom leaves looking a little yellow is fine that plant looks pretty healthy. if your new then make sure u do not overwater, that is very common. keep it up

 

You have an auto and genetics will determine just how big the plant will get, no matter what. It will still be growing when in flowering. You just want to give the plant every chance for success by establishing a good root system and healthy plant before it starts flowering.

 

I would imagine that when a plant is getting all the nutrients it needs its giving it a better chance to grow to its full potential. It may not make it grow bigger or faster then that particular strains genetics but its allowing it to be more healthy.

 

ok so there are a lot of factors. temps and humidty, light, airflow, light intensity and spectrum, growing medium(soil) consistancy, ph levels, and root development just to name a few. and yes there are genetics to consider too. a plant grow any faster or bigger than its genetics allow. what you have to do is dial in the plants needs. just like a race car. you cant make the car go faster than the physics involved with the car, but having everything set to the right adjustments will make it go as fast as it possibly can and that called being dialed in. the nutrients you use also effect each plant differently. you wouldnt feed cat food to a dog and vice versa. yes the reason we use nutes is to boost growth, but that isnt the only reason the plant starts growing more. the more roots the plant has the more water and nutrients it can take up. the plant uses light make energy to apply the water and nutrients. so they need to feed. that is where the nutes come into play. imagine only being able to eat through a coffee straw. it would be hard and woulod take alot of energy just to eat. same for plants. the amount of roots you have determines the size of the straw the plants are eating from. also pH levels are in account here too. the pH is like a filter for whem your plant is eating through the straw. when the ph levels are too high or to low, the filter gets thicker and thicker as they get further and furhter from the ideal pH level(5.8-6.5 in soil) 7 is nuetral and cannabis like the pH to be slightly on the acidic side(anything 6.9 and below)
in the method i use to grow, i want my plants to be as short as possible and as wide as possible. the way i do that is by keeping the lights as close to the plants as possible. i use 6700k flourescent tubes for this.i give them nutes when they have only 3 sets of leaves and thats when they start growing faster. when my plants acheive 5 or 6 leaf sets is when i move them to 12/12 light. thats when my plants really take off. after 1 week of 12/12 under the flourescents, i move them to a 400w HPS. i make sure that my water is pH correct after i add my nutes and let it sit for 1 hour. that way the nutes have a chance to settle in the water and i get a more accurate pH reading. hope that helps a bit. let me know

 

When a plant starts out as a seedling, it spends about 1 month from the time you see it sprout in the "seedling phase". During this time, it is growing a root structure and there is not very much top growth, just a little like you are seeing on your plants. After around 1 month, the plant enters the "vegitative phase". This is when it starts growing a LOT up top ('blowing up', as you put it).

Some other things I noticed while reading through this thread:

1. You posted "and im using bottled water for watering ". Make sure you are checking the pH of that water, and make sure there isn't any sodium or other minerals in there. A lot of bottled waters put sodium and other chemicals in them 'for taste', but these things are not good for your plant. If you can use tap water that has sat out for at least 24 hours, I think that is better than bottled water. If you are using a big bottle, and you let it be exposed to the air for too long, the water's pH will drop a LOT, to the point where it is really not good to use if you are not checking the pH first.

2. You said "its in soil with no nutes and peat moss". What kind of soil is it? Is it potting soil, top soil, or something else? Most potting soils do have some nutrients in them, this is what plants feed on during the seedling phase. It looks like from your pictures that your soil has no perlite in it. If you used soil that was not potting soil, and especially with peat moss in there, it is going to retain water WAAAY too much. Depending on what kind of soil that is, you need to either replace it entirely with a good potting soil, or add perlite to your mix so your soil will drain and your plants don't drown.

3. You said "and I didnt say I was watering alot, sometimes I only give it about 4 ounces of water". You want to make sure you are watering your plants properly. Cannabis likes to be watered thoroughly and then left to dry out. When you water, thoroughly soak the soil and make sure some water comes out the drainholes in the bottom of your pot. Then make sure you don't water it again until the top 2 inches of soil is dry or the pot feels light. You can pick it up after you water it good to see how heavy it is, then when it is time to water again it will "feel light". After you do this a few times you will know when it feels dry. Cannabis does NOT like if you just give it a little bit of water every day or every other day. It should take your plants a few days to dry out after a good watering. Remember, overwatering does not mean giving too much water at one time, it means giving water too soon after the last watering and not letting the root system dry out properly.


Hope some of this helps you out, good luck!