New Grower Problems starting seedlings in papertowel-> Rockwool, low survival rates

[Animatey]

Hi all,

I can never seem to get a good rate of seedlings surviving to their first pair of leaves.

I have read ... maybe 20 guides on germination and starting seeds in rockwool and still can't figure out why I lose so many seeds.

I'm eying 2 seedlings right now that are probably dead within a couple days, one prob dead already. On one the cotyledons are curled inward (down), and the other the they stopped opening altogether.

I currently use the method of starting in a paper towel until the root breaks out, then I transfer to rockwool.

I get close to 100% germination in paper towel/paper plate method, but somewhere in the rockwool something happens to them and they die.

I pre soak the rockwool according to Grodan's website in 5.5 PH with a small amount of food (250 ppm at .5 conversion starting with RO water).

I then place the cubes into a small chamber I have created that has about 60 watts of CFL kept about 8 inches above the cubes.

Temps stay at about 80-85F, I never let the cubes dry out, I never let them get "soaked".

Humidity is only 40% or so, but I don't see how that would affect the majority of them coming out.

I use the 5.5 w/ plant food alternating with just RO water to make sure nutrients aren't building up in the rockwool.

Either the little guys don't come out at all, or they come out hating life, looking really warped and unhappy.

I intend to put these cubes straight into soiless mix (perlite/vermiculite).

I hate rockwool, but I don't know anything else that would work better that is not alive, or doesn't already have nutes in it (ie peat moss/ rapid rooters).

Does anyone have a guide of starting seeds for hempy/soiless that they swear by?

I'm tired of losing so many seeds...

Thanks!

 

[BII]

Why make this so complicated, multi-step? Why not just plant the seeds in their final pots and media? Is rockwool your final medium, or will the rockwool be transplanted into somethlng else?

Otherwise, the Rapid Rooter and similar products, the ones I've used, have no fertilizer in them. And even if what you have has some nutes in them, obviously it's a weak mixture meant to start seeds (and probably better than the initial feeding you're doing).

 

[Animatey]

The reason for the complication is that trying to germ in rockwool itself is generally not recommended. If the seed doesn't germ you can sit there waiting a week to see if it's going to pop out, when in reality it never broke the seed at all. In a paper towel you can visibly see if the seed has germed, and then transport it to a cube.

It's fairly common for hydro to germinate in a paper towel and then move to rockwool which can then go into any hydroponic setup active or passive. The method itself is not likely the problem.

Most rapid rooter type deals have composting material or other organic substances. I've thought about jiffy pellets but they are moss and can contain pests. I avoid anything "organic" in my grows as I like to keep the number of living things limited to the plant itself. Doing things this way means I have never had a single pest in my grows, so I would like to stick with it.

I may try to germ in the perlite/verm and skip the rockwool altogether, however it is recomended against in the hempy writeup on this site and so I'm looking for someone who possibly has another method compatible with my constraints.

Hempy Writeup for reference:
https://www.autoflower.org/threads/hempy-write-up.16233/

"You need to germinate and start the seed in something that you can transplant. It is not recommended to just drop a seed into the perlite."

 

[jingo]

General Hydroponics Coco plugs, they have the perfect amount of fertilizer in them for your new seedling. Nothing is easier in my opinion.

 

[Animatey]

Found a possible culprit with my normal germ process.

I was using a dry nutrient in RO water that I had measured at a stable 250ppm, but I didn't realize how long it was taking for the dry nutrient to fully dissolve. So when I checked the PPMs of the same bottle today they were over 500. This could have been frying my seeds as I was using it to keep the rockwool moist.

I've started another 8 seeds which I'm going to use a new set of nutes on and see how it goes.
I'm also going to skip rockwool and put them directly into the hempy buckets themselves and see if it goes better.
This could prevent me from over-watering if that was the case with the rockwool as perlite doesn't hold much water.

 

[Penrey]

One easy way to have your rockwool at the right moisture level is to take the cube you are working with, dip it in water up to the top of the cube, then place it on top of another cube for a few seconds. The bottom cube will pull the excess water out. I used to do it that way with cuttings I was trying to root and it should work the same way for seedlings.

 

[wiltstone]

Seeds start off with thier own nutes like a egg has a yoke. I don't give mine any extra for about a week. 40% humidity is a good number but in the first days they may like it higher I cover my seedlings with a clear plastic cup for up to a week but that shouldn't kill a seedling just slow it a little. Maybe you should call over a site helper like @Waira he seems pretty good at pinpointing a problem

Sent from my SAMSUNG-SGH-I747 using Tapatalk

 

[icky45n]

I'm guessing there is no help for you, having read ". maybe 20 guides on germination and starting seeds" You then go right ahead and ignore what all of them have said about NOT feeding for week (week or so).
That said, you say "not overing watering", but I suspect you are, because wet roots = death by drowning, over watering is also a major contributing factor of damping off.

 

[Animatey]

I'm guessing there is no help for you, having read ". maybe 20 guides on germination and starting seeds" You then go right ahead and ignore what all of them have said about NOT feeding for week (week or so).
That said, you say "not overing watering", but I suspect you are, because wet roots = death by drowning, over watering is also a major contributing factor of damping off.

I'm guessing there is maybe no hope for your ability to use a forum.

You are spreading misinformation and bringing an attitude to a thread asking for help.

You say that all guides say "don't feed for a week or so."

This is nonsense. Even the guide on Grodan's site says it's fine to use weak plant food when starting in Rockwool, specifically at 1/4 strength.

See the official Grodan video on starting here at 1:40



This isn't soil where there is already some form of nutrition for the plants right out of the gate, Rockwool is inert.

If you had actually read the previous posts in this thread you would see the issue was ultimately due to a dry nutrient being very slow to dissolve, causing higher than intended ppms.

I wasn't over watering like you were "suspecting" because when I went back to liquid nutes, my germ rates have been 100% with the same amount of watering.

Thanks though for the "help"!

 

[Animatey]

One easy way to have your rockwool at the right moisture level is to take the cube you are working with, dip it in water up to the top of the cube, then place it on top of another cube for a few seconds. The bottom cube will pull the excess water out. I used to do it that way with cuttings I was trying to root and it should work the same way for seedlings.

Thanks for the tip, much appreciated. I will give it a try next time around!

Seeds start off with thier own nutes like a egg has a yoke. I don't give mine any extra for about a week. 40% humidity is a good number but in the first days they may like it higher I cover my seedlings with a clear plastic cup for up to a week but that shouldn't kill a seedling just slow it a little. Maybe you should call over a site helper like @Waira he seems pretty good at pinpointing a problem

Sent from my SAMSUNG-SGH-I747 using Tapatalk

Thanks for the advice! I think my issue had to do with this dry nutrient I was using, it was really slow to dissolve and bringing the PH down slowly over time. It was my first time using one and I am back to using liquid nutes now with success at germinating again.

I know that some people start theirs in plain water, and that's fine. Grodan's site says you can use that or 1/4 strength nutes, which I have been doing to get the PH of the RO Water down without having to use PH down.