Yellowing Seedlings?

[radium-]

Hey I have 4 sprouts in 1'' rockwool cubes. I had them in a dome on a heat mat but recently removed dome and mat and put a fan on low by them.

Room temps are 75f and stay that was as there is a digitally controlled heater in there, humidity is around 30%...

My problem is the cubes are drying out, to counter this I have put a bit of RO water(which is the only thing they've been fed) in the tray with them so they can wick it up seems to get the cubes nice and wet again.

On one of them the leaves curled up badly and it was drooping so I carefully removed rockwool from that one and put into a bubbler with 1/4 strength nutes and after two days it seems to be doing better as the leaves have uncurled somewhat and theres new fan leaves coming in.

Before bubbler:

After bubber:



Now for the ones still in the tray it appears there is yellowing on the first set of fan leaves and on the bottom round leaves on them, but there second set of fan leaves coming in are a nice green.





Finally theres one plant in the tray thats doing great, it was my last to sprout and is a solid green and hasnt had any probs yet.



Should I put them all in bubblers and if not when? How can I keep cubes from drying out?
What could cause that yellowing where I have only been giving them RO water pH 6.5-7 ppm 003?



Thanks guys!

 

[Guest]

ph is kinda high for seedlings dude. 5.5 to 6.0 sounds better than 6.5 to 7.0
good luck

 

[Guest]

Hi Radium,
They need food. Yellowing in seedlings usually means their lacking Nitrogen. Without N, they don't produce chlorophyll, which they need to stay nice and green. I would begin feeding with your veg formula ASAP. They should recover in a few days.
Good luck,
GL

 

[Guest]

my pH is 7.0 on point outta tha tap

never once have i corrected the pH before doin seedlings in oasis or rw

420KM is correct, but i do not think this is the reason your babes are unhappy.

is there a fan blowing fresh air on them 24/7 ? if not there should be.

also check with your finger and feel those rw cubes..if cool to the touch you may want to consider a heat source (thermostatically controlled hydrofarm heat mat maybe?) underneath..

also get that light closer if you can...maybe you just moved it for the pic
anyway..
seedlings need a LOT of light...only time you want LESS light, is when cloning, before roots...use as much light as you can for seedlings anmd mix up red and blue flours (CW,WW,DL etc) for a mixed spectrum leaning to the blue side of things.....youll see 6 nodes in 3 inches like me

seedlings love the flourescents, just gettem 1" away and get a pc fan blowing on that tray to rustle those girls and build a stronger stem/encourage faster growth.

hope this helps

 

[Guest]

Hi Radium,
They need food. Yellowing in seedlings usually means their lacking Nitrogen. Without N, they don't produce chlorophyll, which they need to stay nice and green. I would begin feeding with your veg formula ASAP. They should recover in a few days.
Good luck,
GL

good way to kill em


theyre too young as far as i can tell .. maybe you see pics i dont b/c those show only the first baby leaves STARTING to come through, as well as the cots......i have seedlings in cups of water over-germed that have more leaf than that bro, you must have not looked too hard at the pics, look again

how many days ago did you put them to cubes?

next watering id add a nice splash of h2o2 to a quart of water then feed them from the bottom.

NEVER mist your seedlings or clones DIRECTLY, rather, mist the walls of the greenhouse, and the dome, but never the seeds...

leave the cover off for a few minutes with the fan on 3 times a day to prevent damp-off disease..

if you NEVER USED A COVER, and just germed and stuck em in rw in 30% RH room, theyre going to grow super slow, a few may crisp up/curl/discolor and some may even die...

if theyre too bifg now for a dome, or to cover with saran wrap, id definitely get a cheap humidifier from the pharmacy and get that going in the nursery there...

if you cant afford to buy anything,

grab any old oscillating fan, add a wet sheet over the grille, and turn on oscillate and you have yourself an instant humidifier...

also , if broke, you may try perlite (wet) as a 'substrate' below the seedlings but BEWARE: use some sort of raisers to keep the bottoms of the cubes off the perlite...this is a must if doing perlite humidification. keeping this covered with a dome achieves 100% humidity, just remember to add water to the perlite when it starts to dry up, and REMOVE THE DOME,
AND FAN FAN FAN 3 TIMES A DAY OR YOU RISK DAMPING-OFF
hope this helped a bit more and have a good 1...
and good luck!

 

[Guest]

On one of them the leaves curled up badly and it was drooping so I carefully removed rockwool from that one and put into a bubbler with 1/4 strength nutes and after two days it seems to be doing better as the leaves have uncurled somewhat and theres new fan leaves coming in.

The plants doing better because it was fed, CJ. I have always started feeding seedlings @ this stage for years with no troubles, to say thats a good way to kill them is completely wrong. I start most seeds in a soak that contains 1/4 strengh nutes.
GL

 

[Guest]

you didbnt say 1/4 strength nutes (first of all)

you said , and i quote,

I would begin feeding with your veg formula ASAP.

point is, greenleaf, that a plant this young, does NOT require nutes yet...

if it's nitrogen the cotyldons, most of the time, will begin to yellow from the inside out and then go necro.

those cots are green still, its not an N defieciency....

feeding sick seedlings like this, anything but a very very weak, very diluted fert., is asking for trouble

revive them first, then fix anything that is wrong...but i dont even see yellow leaves nor yella cots it looks and sounds like they got wet, too low an rH and theyre not ready for the brave new world, or an air quality thing...

they look unhealthy, and altho it may not hurt to do the weak strength thing, adding N at this point isnt going to magically revive them.

 

[MynameStitch]

the problem is this for one the rockwool is to soakedand soggy stuff causes ntirogen problems

the rockwool needs dried out a bit and when the roots start to grow out of the rockwool then you can start to feed them a very weak amount of nutes

and you are supossed to ph balance them by soaking them in ph balanced water 24 hours before use

every strain is different and is different to certin ph levels

 

[radium-]

CaptainJack: if it's nitrogen the cotyldons, most of the time, will begin to yellow from the inside out and then go necro.

those cots are green still, its not an N defieciency....

Hey just wanted to say the coteyldons are yellow on two of them




I put the dome back on and humid temps inside dome went to 60-70 range.