6-Harvest Grower's plants keep dying in new grow room

Good day to everyone,

I hope someone can help me with this situation that has been driving me crazy for the past 2 months.

I have been able to harvest our favourite plants from seeds for 6 grows now, a total of 20+ plants. I am by no means a great grower, still plenty to learn. But never have I imagined I would run into a brick wall such as this.

So a few months ago I moved into a house with a proper grow room. I used to live in an apartment, used to need lots of ONA block to mask the smell. Now i have a properly equipped grow room with ventilation and carbon scrubber.

So after everything has settled down with the move, i started 6 seeds.
Everything seems fine till the 4th day, when yellow/brown spots start to appear at the tips of the leaves.
Soon after, my girls start dying.

A liitle background, I grow in soil mixed with perlite, using LED lamp.
Grow room temp is around 24 celcius/ 75F.
Humidy is a little high at 75, a dehumifier is ready to lower for flowering stage.
Water PH is measured and adjusted.
Grow room has been well aired and cleaned, so no issue with paint fumes or other contaminants.

First i thought, the seedlings are overpowered by the new 600w LED. Hehehe i collected quite a few new toys during the renovation of the new place. Ok so I started over with the old trusty 150 UFO LED that has served so well in the past.

But second batch start dying too...

Third batch gets bottled water, while the new house tap water get sent to lab for test.
Test come back fine, and my girls died too.

Maybe I had a bad batch of potting soil, so I sourced from elsewhere, different brands, different suppliers.
Nope, they died too...

Maybe the perlite I had got contaminated somehow.
So on the latest batch, i started 1 seed in pure soil, and 2 seeds in soil mixed with coco.
Lo and behold, the same problems has reared up again.

Is it possible the light is overpowering the seedlings, as the grow room is painted white for better reflectivity? Although I have tried increasing the distance to the light, which has caused some stretching in my deceased girls.

The photos are of the 3 in the latest batch.
The leaves have started yellowing, more pronounced at the tips and the centre running through the leaves.
They will be dead in a few days...

Any diagnose?

How often and much are you watering. It's super easy to over water seedlings especially in a decent size pot.

Something in the air possibly , is there an intake and out take for the room? Have to have lights real close to fry seedlings afaik , like Thundercat says how much are you watering.

Where you able to get to harvest fine in the previous place and now this is happening here?

Interesting, Are you getting any root development? Dying four days in weird considering your track record of success prior.

I fungicide my room at least once a year, you may consider this, Since you have some experience under your belt makes it more puzzling.

2 things to consider, I keep my humidity in the <50% range simply because it causes less possible problems, the other is I only start my seeds and clones in Jiffy Starter Soil, never a problem.

Are you getting enough air exchange with the new system vs humidity.

Good Luck will be following

Hi cap,
That's a pisser. I'm in a new room too. Bought a fairly powerful LED unit that's 600 like yours. Burnt my first crop. I was following the directions for the light. Whereas what I should have been doing is to dim it low and ease it up till it was doing it's job with no damage. I thought I was doing something wrong with nutrients. So I'd look very closely at your light and how you are using it.
JD

Good Point JohnDee, mine start with cfl's, then a good 1.5 ft from 300w led in veg before they hit the flower room

HDPursuit said:

Good Point JohnDee, mine start with cfl's, then a good 1.5 ft from 300w led in veg before they hit the flower room

Click to expand...

I keep my LumiGrow 650 at 3'...and ease in the reds slowly till I see plants like it. About 60% of it's output is red so I have a couple 315w cmh to balance out the spectrum.
Good luck,
JD

Im really interested in finding this out. Its strange to see the exact same leaf coloring on the different potting solutions too I see Coco and soil look the same. I was going to say maybe try recalibrating your PH meter. They do go out sometimes and it looks like it might be an iron deficiency which can happen at anything above 7.0 usually in soil i keep it around 6.8 so if the meter is off by a small amount you could easily over correct the ph.

Did you wash/ph that coco? I've gotten dirty and salty coco before and had the same signs you're describing...

Took quite a good washing to get rid of it

When you pull the dead seedlings how do the roots look? If they look healthy & white I'd suspect they are getting cooked from above, good luck... I just pulled a bunch of Orange Sherbert #3 Tonight I bought them from someone online out of 36 seeds 12 germinated after 7 days most had odd irregular leaves, slow stunted growth, the other strain, purple snowman all germinated and are growing like weeds, same soil, water lights etc. Bad genetics

+1 on the over watering,seedlings need very little to start with

Thanks everyone for the replies.

I don’t believe it’s an issue with overwatering, since the medium is well aerated.
And I only gave a splash of water when planting the seeds and then 2-3 days later.

Nor it is with the light distance and PH. I am using my old 150watt led at 60cm distance and I am using 2 ph meters to be sure.

Coco is well washed and I only mixed with coco in the fifth attempt, all past attempts were soil+perlite

I have managed to harvest 20+ plants that is why this is so frustrating.

nobighurry mentioned checking the status of the roots and they seemed white and healthy.
I am suspecting it’s the room factor.

Would high humidity has such a fatal effect? To kill the seedlings in a few days would require something extraordinary I feel... The grow room is 2meter x3m x 2.5m. It is air conditioned.

A total head scratcher..

Cilacap said:

Thanks everyone for the replies.

I don’t believe it’s an issue with overwatering, since the medium is well aerated.
And I only gave a splash of water when planting the seeds and then 2-3 days later.

Nor it is with the light distance and PH. I am using my old 150watt led at 60cm distance and I am using 2 ph meters to be sure.

Coco is well washed and I only mixed with coco in the fifth attempt, all past attempts were soil+perlite

I have managed to harvest 20+ plants that is why this is so frustrating.

nobighurry mentioned checking the status of the roots and they seemed white and healthy.
I am suspecting it’s the room factor.

Would high humidity has such a fatal effect? To kill the seedlings in a few days would require something extraordinary I feel... The grow room is 2meter x3m x 2.5m. It is air conditioned.

A total head scratcher..

Click to expand...

Poor air quality/air exchange maybe a factor? Humidity is fine for seedlings. Did you thoroughly rinse your perlite/coco prior to planting? Almost seems like a medium issue to me??

I was going to say the same thing about the air quality. Is this grow room in a basement by chance?

There could be a gas leak that you are not aware of, or maybe seeping radon but I have no idea what effect this has on plants.

I would see if you can get some air quality measurements or cycle fresh air into the room and see if that helps

do you have an ozone generator anywhere in your house? i was using one on a timer to help with odor, and 4 periods of three minutes a day was enough to fuck up my plants pretty good, had to cut back to one minute, twice a day....which still helps with odor and any contaminants in the air, but doesn't hurt my plants....
just a stab....

Let's see some new pictures.
It's been 3 days.
Let's see what the new growth looks like.

Cilacap said:

Thanks everyone for the replies.

I don’t believe it’s an issue with overwatering, since the medium is well aerated.
And I only gave a splash of water when planting the seeds and then 2-3 days later.

Nor it is with the light distance and PH. I am using my old 150watt led at 60cm distance and I am using 2 ph meters to be sure.

Coco is well washed and I only mixed with coco in the fifth attempt, all past attempts were soil+perlite

I have managed to harvest 20+ plants that is why this is so frustrating.

nobighurry mentioned checking the status of the roots and they seemed white and healthy.
I am suspecting it’s the room factor.

Would high humidity has such a fatal effect? To kill the seedlings in a few days would require something extraordinary I feel... The grow room is 2meter x3m x 2.5m. It is air conditioned.

A total head scratcher..

Click to expand...

It’s possibly your tap water being bad

if you're using coco, is it possible you've gotten down to the bottom of the bucket, literally? the "fines" settle down into the bottom, and collect. i throw out (into the garden) the bottom inch or two when i rehydrate a big brick, easier than straining it all.
the fine dust doesn't work nearly as well as the larger fibers, it doesn't pull in or hold oxygen nearly as well, and can drown roots, and will also hold a lot of the contaminants present

Back to the drawing board...

I guess when the yellow spots start appearing, they are already dead

Check the ppm of tap water