Rockwool seedling-Where am i going wrong?

Ive run a few threads and tried all advice given to me but i still have lasting problems with my 1.5" rockwool cube seedlings.

Ive tried them barely moist all the way to dripping wet and bottom watering, top watering, once, twice and three times daily. Ive run every different ph even bought a new bluelab ph meter. Preconditioned cubes for various times and differing ph.

I can happily say i can germinate and get roots within a week and pretty sure i got this down to a "T" just dunking the cubes every 24hours and shaking a little excess off. Really its become so easy i feel like a pro and nothing fails untill the first true leaves appear and then slow stunted purple stem growth.

I been scratching my head for a few days, water and watering perfect, ph dead on, temps/humidity spot on, tap root/roots showing out the bottom of cube, good ventilation, no bugs! There seemed like nothing i hadnt worked at and then it dawned on me that i had been using plain old tap water no ferts or ammendments on the advice of many.

Hmm i thought then without hesitation mixed up a ph'ed batch of 250ppm ferts and dunked each cube, first the rocket leaf, then the lettuce and finally the mj seedlings. They've had two feeds and already the rocket leaf plants stems have turned browny green as oppose to purple, the lettuce started growing new leaves as lppose to just stopping after first true ones and my mj plants have losrt their slight wilt, a little purple and have put on the most growth since day 1.

Im always jumping the gun but is it just that my seedlings needed ferts? My tap water hits 70ppm on a bad day and contains very little of anything. Ive described how after the first true leaves grow a little then thats it they just up and stall and i have really worked hard at watering and ph which hopefully shows in the quick rooting and 100% germination rate.

Im lost but adding ferts as soon as first true leaves are popping out seems all i got left, this kinda flies in the face of peeps who said i can go three weeks no ferts (unless they have very noutritious tap water).

Anyway im just hoping this leap is the leap home and feeling a little Sam Beckitt right now!

This is last weeks seedling so best part of two weeks old and nothing but tap water till now. It started great then went purple stemed and stunted, only time its grown was last day after getting ferts.

Im more intrested in this weeks seedlings as if ferts was the answer they will look better than this in a week, if not i just dont know wtf!

Roots

This seedling is a few days old but over a week younger that the one above for comparison. Can see how it all starts ok but even here its stems purpling and growth is halting. Really hope these ferts change somthing for the better

roots + first set of true leaves= they need nutes from now on.

I never could get my marijhuana and rocket stems green, always purple, but my lettuce always come up green.

The rocket seed on the right come up before i added ferts a day before the one on the left that came up yesterday when i gave ferts. Not the best pic but the one that got the ferts earlier on the left has a brown green stem and the one on the right purple. Maybe this will happen with my mj plants and i have another popping up in two days in a cube with very light ferts. Ignore the lettuce seedling behind them.

Sorry to post non mj pics but these seedlings made me think possibly ferts are the difference (and sorry for all the posts, damn phones hard work)

Dude i get a root and tiny first leaves at day two from breaking the surface , im not trying to say your answer is not very specific but yer i am sorry. I sorta take that to mean give it very week ferts day 2 onwards?

Mowgli Ma-Fên said:

roots + first set of true leaves= they need nutes from now on.

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Formulex, Ionic ph 4 & 7, Ph meter storage solution, Essentials ph up/down, Vitalink plant start, Roots Excel, Liquid oxygen H2O2 and a bluelab ph meter from left to right. Running some H2O2 some not and just started yesterday with the plant start and formulex, been playing with the roots excelurator ever since i got it trying some with some without. Hoping the plant start and formulex make a difference.

I cant be more detailed than this and im playing the "try for yourself and see noob!" waiting game at the moment...

What is ur setup like? lights, temp, ph range, humidity. there could be just one little thing affecting the little ones.

They look fine plant them

Not really sure whats going on but a couple if things come to mind. You may need to get those cubes into what ever your growing in sooner. Rock-wool is pretty finicky and too much moisture is my biggest issue. As soon as I have a tap root they go into the hydroton, My sprayers are cycled for 15 min every 4-5 hours until roots are established, any more than that and they do real poor. I do add nutes right from the start but very light, in the 200 range.

Budley Doright said:

Not really sure whats going on but a couple if things come to mind. You may need to get those cubes into what ever your growing in sooner. Rock-wool is pretty finicky and too much moisture is my biggest issue. As soon as I have a tap root they go into the hydroton, My sprayers are cycled for 15 min every 4-5 hours until roots are established, any more than that and they do real poor. I do add nutes right from the start but very light, in the 200 range.

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They got purple stems and stunt after the initial few days growth, i added light ferts and started seeing positive changes although its too early to say.

My question is if a light dose of ferts is all they needed as these were just getting ph'ed water and not doing so good.

My next batch will start at 200/300ppm see if they are better than these on tap water.

Pics arent the best but the plant above at 2 weeks with few roots showing should be way bigger and not purple stemed. Already they look happier from the light ferts i gave them yesterday.

keeper1981 said:

They look fine plant them

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They will go into an x-stream V2 propogator but no reason they wont do well in those little plastic holders they are in at this early stage. Roots quite like the little air gap at the bottom as well as they explode everywhere.

I just quit the rockwool. That shit sucks. But that was easy as i do soilless. For those that do hydro im not sure what the alternative is...

smokinthegoodstuff said:

What is ur setup like? lights, temp, ph range, humidity. there could be just one little thing affecting the little ones.

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T5 lightwave unit with growlux tubes, fan keeps between 23/25°c, i water once a day when cubes are lightweight and have most ferts, amendments and meters a grower could want, humidity averages 50% with no extremes and i have previously spent a lot of time working through ph and watering which have given me a pretty solid routine and nice healthy roots. I really doubt fine tuning anything here will not make much of a difference and really just hope its a fert problem as im at a loss on this one.

Lol dude i quit soil and promix for hydro, these rockwool cubes are just till i get them in netpots and aero systems.

Gquebed said:

I just quit the rockwool. That shit sucks. But that was easy as i do soilless. For those that do hydro im not sure what the alternative is...

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"They will go into an x-stream V2 propogator but no reason they wont do well in those little plastic holders they are in at this early stage. Roots quite like the little air gap at the bottom as well as they explode everywhere"

But there is no reason they cant go directly into propagator now is there? Why do you not just put the directly in? Just curious is all, my seedlings go directly into my pots and do great, again if I dont overwater.

Budley Doright said:

"They will go into an x-stream V2 propogator but no reason they wont do well in those little plastic holders they are in at this early stage. Roots quite like the little air gap at the bottom as well as they explode everywhere"

But there is no reason they cant go directly into propagator now is there? Why do you not just put the directly in? Just curious is all, my seedlings go directly into my pots and do great, again if I dont overwater.

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I think i have a better control of watering in the plastic containers as oppose to a aero propogator although i could set it to water once every 24 hours and try to replicate what im doing now. I cant give them a little shake in the propogator and until i have a lot of roots it helps with the not overwatering part.

I also havent bought a propogator yet and challenged myself to get good rooted cubes first as part of the learning curve. There is no major difference because many options exsist like bigger cubes, aero, aqua, nft, dwc etc etc i just saw the most sucessfull grows started with a good rooted cube be that seed or clone.

Like you say its more personal choice as both ways should work equally well.

Purple stems are not unusual in my experience long stretched out stems generally a lumens issue . I quit rock wool years ago .easier to start in solid then rinse out of the dirt and into clay balls and nets.

PsicloneX said:

Purple stems are not unusual in my experience long stretched out stems generally a lumens issue . I quit rock wool years ago .easier to start in solid then rinse out of the dirt and into clay balls and nets.

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Yer the stems start out green, a dead give away they shouldnt be purple, combine this with slow growth and i reckon its the plants way of saying somthings up.

I dont believe that hype about purple genetics, thats more a temperature related factor that anyone can do with a cold room and some well flowered bud, purple strains just more prone to it.

Well good luck I hope you get it sorted. IMO you would be better letting the plant establish roots in the system your going to run them in if doing seedlings. I run low pressure sprayers and basically set the rock wool with newly germed plant on one layer of balls, then fill to the top of the cube. Set sprayer to once every 3-4 and sometimes upto 6 hours. Once roots are fully established, about a week I then fill to the top of the pot with balls and set spray for every hour and off they go. I struggled with RW till I started doing this, now nary a problem.