Nute burn vs Heat burn

Hello all,

I'm on my first grow with Nirvana NL autoflowers. They're almost 5 weeks old and I can't tell if my light is either too close or if I'm nute burning the plants. The light is about 8 inches away from the plants, and I performed the hand-test to see if it was hot after a minute and it has been very cool.

Here are some pics. I'll add some more momentarily, having some issues uploading photos...

The fert i'm using is foxfarm growbig ( I read that this fert is better because the autos have short veg growth). I've tried to be very minimal with my dosing, and am including water with the dosing. I have only ferted them a couple times.

plant #2...............

looks like nute burn, what kind of lights are you using?

Yea I'd say nute burn.
Lay off the nutes for awhile
were you giving them full or 1/2 strength?
should be 1/2 what they say.

nute burn?? id say micro nute deficiency. nute burn would look more like necrosis on the leaves, not just discoloring. the light being so close is whats causing them to be short and bushy, thats good, to an extent.
what are you feeding them?

at the same time, this also looks like bad soil, and its time to water.

and please turn off the HID lights when taking pics!

yea its hard to tell from the pics. are the tips yellowing? or are they turning brown and dying?

Do you have any equipment such as moister, ph, nutrient meters to tell rather than guessing? I would invest in some quality equipment. I hate guessing while growing. These tools are essential. I am so surprised that so many growers are not prepared when they start their grows....not being mean...just saying.

check wether ur soil is pre nuted/fertalised if it is it should be good for up to 4 week without adding nutes...i havnt used ffof but if u added nutes itl be nute burn...8 inch seems a bit low if its a hps light especially wen they small..

Hi guys,

Thanks for all the responses. The light is a 400W HPS. These plants started in my closet under pretty minimal lighting(diff combo of tube fleuros and CFL's I found in my house), which I imagine has to do with their size as well. I do kind of regret just jumping into it, but I was very eager to start learning and gaining experience.

The fert is foxfarms big bloom or whatever. I felt I used very little, but maybe I am wrong. The soil is ocean forest fox farms. The top of it is just try, it's fairly moist about an inch down. I will take some better pictures later today.. sorry about the lighting.

nick- the tips are browning and dying. I crumpled up the edge of a leaf this morning.

A theory I have is that I did transplant these plants into bigger pots with fresh soil. But I also fertilized the old soil slightly before transferring. Feeling pretty noob saying this but could it be the combination of leftover ferts + fresh soil = nute burn?

A 400w 8" away from that small plant is way to close.When my plants are that size i have my 400w about 4 -5' above my plants and lower as the plants get bigger and stronger then add my 600w.I have a lot of practice starting seedlings with a 400w.I use an old bulb at 1st and keep it well above my plants.I know this isn't the most eficiant way but i plan to get cfls for seedlings when i get some bread.I don't ever put my lights 8" away from my plants,usually 15-30" depending on plants.Raise your light my friend.
I'm in hydro but my cuz uses ffof and said he does'nt have to add nutes for a while with that soil.Light 2 close & 2 much nutes easy to fix my friend.

yes sir, first thing I did after I read the responses was raise the light, 4-5 feet? that seems so far. is the light chart not accurate ? http://www.thctalk.com/gallery/data/500/HPS-Light-Distance-Chart.jpg or is it all dependant on the size of the plant ?

ldawg said:

yes sir, first thing I did after I read the responses was raise the light, 4-5 feet? that seems so far. is the light chart not accurate ? http://www.thctalk.com/gallery/data/500/HPS-Light-Distance-Chart.jpg or is it all dependant on the size of the plant ?

Click to expand...

As the plant starts to get bigger and stronger you can start to lower your light.400w is a lot of light for seedlings and small plants they don't need it yet they are developing their root system.

autobahn101, the girl in your avatar has a nice pooper. Stay off the nutes. The soil should have enough nutes to last the veg cycle. checking ph? using tap water?

I am also using foxfarm oceanfloor.....before that i had it in miricle grow from seedling...ohh ouch big mistake..and it looked like that...i think its nute burn and now its in ffof and it still looks like that....how can i fix that,..i flushed it last week and i dont see any large improvement....should i just cut it and smoke it now and take the headache punishment for doing something that stupid or do i have a chance to make the plant grow into something that the creator intended it for?ohh right now its 6 weeks old....can i keep hope alive?

kepp it planted.