SOIL Seedlings have stopped growing and leaves are turning

[BlazeRunner]

Hi all, new grower here so thanks for your patience. This is my 3rd attempt growing plants from seed and I keep getting the same results. Extremely slow growing plants with yellowing leaves that mostly die. My most recent plants emerged from the soil on Oct 10 so they are 10 days old and I think they are going down the same road as my previous sorry ass plants. The plants did very well the first couple days emerging from the soil and growing a first set of leaves. But then all growth stopped. I wouldn't be worried because I've read that seedlings can often stall while the roots grow, but about 4 days ago the leaves started to get a rusty red color on the edges and then today a yellow blotch appeared on one of the leaves (see right side of top leaf in picture). This is the same pattern as my previous plants.

Before my first grow I did a ton of reading and felt like I had all the important stuff taken care of with each attempt I've tried to improve my setup but I really can't imagine what I'm doing wrong enough to cause such catastrophic problems. Here's a rundown of my setup, please let me know if there's any other information that would be helpful to diagnose where I'm going wrong.

Seeds: Sativa. Germinated in paper towel.
Soil: standard potting soil from the hydroponics shop (pretty sure no added nutrients) with perlite mixed in maybe 20%
Lights: Two 23W CFLs on each plant (1x 2700K, 1x 6400K). I've got the lights about 2-3 inches from the plants (see image). Lights on 24 hours a day.
Temperature: This has been fluctuating a fair amount as the temperature in my apartment has been fluctuating a lot but its mostly been kept between 20-30C (just a couple times the temp has creeped above 30C).
Humidity: Also been fluctuating quite a bit between 40-60%. I've got a humidifier on now which is keeping the humidity above 50%.
Watering: I've been watering with pure tap water left overnight with no added nutrients. I've watered 3 times now and have let the soil dry out in between waterings.

Thanks a lot for reading. Any advice is greatly appreciated.

[Aloner]

Two things that come to mind -- what is your water's pH and what is that fan for? Correct pH is immensely important and seedlings don't need air blowing on them.

[Canuck147]

Only thing that pops out to me is, why do you have the lights on 24/7? Are these autoflower or photoperiod? If they are photos, then they need some dark time - 18/6 - if they are autos - then disregard my rant.

[BlazeRunner]

Thanks for the feedback.

Aloner: the ph of the water going in is 7. I know 6.5 is perfect but didn't think it was a huge deal but I could lower that for sure. The fan is keeping the temperature down. Without it thr temperature below the lights climbs above 30C. Do you think the moving air could be a problem?

Canuck: they are photoperiod. I'd been wondering about that. I've never been able to find any explanation of the merits of 24/0 compared to 18/6 so I just went with 24/0 because it's easier. But yeah if it's important I can hook up the timer. Save a bit of money on electricity while I'm at it so that's cool.

[Aloner]

7 is the very top end of what you want in soil. Me, I would bring it down a bit. Plus different nutes uptake most efficiently at different points on the scale so switching it around from watering to watering can also be helpful. The fan could also be causing problems, If you need it (sounds like you do) I would aim it so that it's not blowing on the plants at all.

I've only got one grow under my belt but I kept my seedlings on 24/0 until I moved them outside, like 3-4 weeks straight, and they did very well.

[Canuck147]

You say you did a ton of reading, I did also. The amount of light ones plant gets was quite a few chapters long........

[Weed Pharma]

As far as the light is concerned- I run 24/0 until the 4-5th node- then reduce to 20/4.
I treat autos and photo's the same except photo's get flipped to 12/12.
-Neither one's need a rest time, but the cost reward deminishes - where the increased light doesn't justify the energy costs.-

I agree, the biggest issue is the fan (face it the other way) along with the heat. It wouldn't hurt to move the lights up a little bit and see if the plants bounce back.
I would give low strength (pHed) nutrients at this time.
3 waterings in 10 days for soil sounds like a bit much.

[D.A.A.S.69]

Morning blazerunner, on my seedlings I keep the light on 24 hours a day, they don't need any dark time, I would definitely add more cfls at this stage an keep them no further than 2 inches away. I use a fan on my seedlings too but it's at a distance that barely makes them move, you sure don't want your fan very close when your seedlings are that small. That yellowing sure looks like overwatering to me , they do not like very much water at that age, I wouldn't do anything but let the soil Completely dry before watering again ,then don't use but a little water. Let your soil dry out real good.

[tyler_ hobbyist]

As soon as u get ur 1st true leaf (leaf with serrated edges) start feeding half strength nutrients and at this stage 1 tsp of water is more that enough wait till the soil starts to feel dry then water again. And personaly I use nutes every watering. My seedlings also get 24/0 lights til there at about 5 or 6 nodes then 18/6 I find this the most cost effective/ yeild for my money. As far as ur lights seedlings do not need much light but they do need lots of blue spectrum or they will strech iv had seedlings stress at 45 watts per sqf. Long story short u have a nute deficincy that needs to be fixed with nutes and proper ph 6.5 this is extreamly important!

[Potted]

PH,PH,PH,6.3,to6.5 no more my 2$

[Professor]

I think it's just that fan, man. Even on low, a big fan like that, that close, you're drying those poor babies.

[Gingerbeard]

This post is 7 years old. He's probably moved on.