5 days after she sprouts I noticed light brown blade leaf and curling up.... using ffof and Mars hydro sp150.. any clue

Potentially over-watered. If you initially saturated the soil when planting, it will take at least 5 days before it needs to be watered again. Lightly spraying the top of the medium once a day should be sufficient - if the top of the medium is dry. I hope it's not an over-watering issue because when they are that young it can take them awhile to recover; many growers just start fresh since a new seedling will mostly likely outgrow the stunted one.

I would def use it. Some people are against mixing it in water but It works for me then when transplanting I sprinkle on the actual roots and in new hole.

I usually add it once a week into my watering there isn't much proof on "too much mychroz" if you use recommended does.

But your Humidity was WAYYYYYY too high man. Refer to this VPD chart to stay with in range.

:) I had same issue and hey were curling and eventually fixed themself in a week.

Thanks I had the light at 24” now pushed to 30 temp was at 80 and humidity at 86.. now got humidity at 60 and temp at 79

How often are you watering and how much?

Hey Jason can't really tell from this picture but from your description I would treat for heat stress. Curling up leaves as well as browning on the leaf would indicate for both.

What distance are your lights at?

What's temp?

Do you have fans oscillating in the room?

Also did you use any nutes in the feed because avoid that if using FFOF soil for a few weeks.

I would push lights up more and fans if you do not. Keep the course they are still young they can recover also don't water ALOT during this stage give them small amounts of water more often is what I do during this stage because the roots aren't very developed to handle a lot.

Also next feed maybe add a Mychro to help it recover (Great white does wonder)

Stay positive :)