Seedlings are Curled Back and Turning Brown

[BigOlBug]

Hello!

This is my third grow and they both ended up great thanks to this forum.

But we just moved to a new house and the water is super hard (750 ppm). Fortunately, we have a basement with plenty of humidity so I got a large dehumidifier and it harvests about 5 gallons of clean water a day. The water powers my humidifiers and I am using it on the plants.

Sadly, after the first week the seedlings are showing some issues. The leaves are curled back and are turning brown on the edges. The two newest leaves have it on their tips.

I think it's too much light, over watering, or perhaps they need nutrients earlier since I am using what amounts to distilled water?

Any opinions would be most appreciated!

Grow Specs:

• Spider Farmer SF4000 - 30" full power - 18/6
• Vivosun 48x48x80" tent
• Vivosun 6" 440 CFM Inline fan
• RH - 62%
• Temp - 75-80
• Dehumidifier water (ppm 26)
• Coco coir (mixed with 5 ml/gal cali-magic)
• Watering 1/2 gallon every other day with 5ml / gal cali-magic (335 ppm)

[Bigripper121]

Too much light. I'd go 45%

[Gingerbeard]

Stop using distilled/dehumidifier water! Regular tap water has things and junk in it that are good for the plant. Distilled water is void. I will not swear I read this, but I remember reading DW can actually suck nutrients out of plants. Bottled water, fine. Machine water, fine. Use tap unless it is uber nasty.
You didn't mention pH. I run mine between 5.8 and 6.2.
Based on my experience with an LED and HLG 360 Elite, if you sprouted in that coco, under those lights, your lights are not the problem. Personally, I've never done an acclimation period, although both manufacturers suggest one. Check your manufacturer's specs about light distance.
Do not water your entire pot for one seedling. It's okay for your seedling to get damp, not dry. At this point, watering a 3" radius around your plant is plenty.
Domes are only needed if you have to keep a humid environment or don't want to water as often. Having the domes on, creating humidity, and a dehumidifier are... well... matter and antimatter.
But, yeah. That first thing I said. Your water is a bad choice. Even with nutrients. Fill a gallon jug and let it sit out, overnight, to off-gas chlorine that may be present. pH. CalMag. Let her dry-to-damp.

[BigOlBug]

Gingerbeard, thanks for the comments.

I run between 5.8-6.2.
I'm at the right distance per the manufacturer, but I see where lots of people dim that unit to 40-60 and adjust upwards till flowering at 100%.
I water a 4" radius and only had the domes on until they sprouted. (Not sure what possessed me to get those for the grow).

I've done a ton of research on using dehumidifier water and I've seen where mold can be an issue if the water sits or you have an older basement. I empty the unit twice a day and the house is new, so no mold. As long as you add nutrients to account for the lack of in the water, people seem to get good results from it.

My problem is that we have very hard water here. The TDS after sitting 24 hours is 650ppm. I am looking in an RO system, but that can be pricy.

But, you and everyone else have made me realize that I have too many variables going on with this grow. I'm gonna use tap water and Nebula Haze's recommendations for coco and the GH trio.

Thanks!!

[Gingerbeard]

All good. Grow medium, liquids, light. Everything else is science.

[SoOrbudgal]

Way to much water go back an read the basics

[BigOlBug]

Good point SoOrbudgal.