Could it be that the seeds may have been weak to begin with? Ru switching vendors and trying someone new?
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No. Actually the seeds were stored good (at 5 degree celcius in the fridge) and were from different vendors. Also different strains.
Actually I still got some auto seeds which I dont need. So I will do some tests now with the cubes and the water and see if I get different results in the starting phase when starting from new and changing a bit the different variables, like watering, light,fertilizer or ph.
I guess I will do a test run with some presoaked and some not presoaked cubes. Maybe variate the amount of water and see if my osmotic water is good.
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with rockwool remember,
Don’t mistreat the cubes by excessive squeezing. I try not to squeeze at all. Do rinse and ph down the cubes first. There are two temperature zones, one above the cubes and one below. don’t be to warm under the cubes or at the rootzone. don’t let them sit in standing water.
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It depends on the strain. Some plants turn on switches in times of stress, or in flower that never get turned off and can permanently affect your mother plant. Others can switch them back off.
I would say still select mother plants, keep them in 24hr light once they are mature, and see if they are permanently affected.
Then keep on sprouting new seeds, if you get something better than things you already have then swap out your worst for the new plant. Keep doing that and you will limit the long term effects of stress on your current crop of seedlings.
My suggestion would be to always sprout seeds in soil then use that plant as a mother and take a cutting from it to replace her which can then go in any type of system. It gives them the best start and reduces stress, stress which can make a good plant bad. You will never make a good plant from a bad seed but you can make a bad plant from a good seed.
The short answer is nobody could tell you if you have affected the quality of your plants until you grow them so that is my advice to do. Grow them and cull the bad ones, keep the good ones, germinate some more seeds, cull the bad ones keep the good ones. If you have too many mothers cull the bad ones.
rinse, repeat.
(rinsing soil off the roots to put it into another system is also an option)
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grodan doesn’t use lime as a binding agent any longer, soaking hasn’t been necessary for a few years at least, they should be PH 5.5
@SamandMax i think you can take out the heat pad… 26C seems too hot imo… 400w at 120cm should be fine … use light fertilizer … maybe start with a smaller batch until you get your environment and system dialed in…
edit: ya 26C is like 79F i think that was your problem… cooking the root zone
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I think ya should run maybe a couple peat pucks, soil , and some compost in small cups and see what the results might lead to !
Acutally I was reading in Cervantes new book ‘The Cannabis Ecyclopedia’ that seeds germinate and grow best at 26 Degree Celcius (page 53 and 55). Maybe he was refering only to the earliest stage of growing. But also later when the seed is a seedling he says that a bit additional soil heat is good and helps the plants (page 58).
Also he says that if not growing in rich organic soil or pre-fertilized mix, start feeding 2 to 4 weeks after seeds have sprouted. And that some gardeners wait until leaves yellow to begin feeding and to use a mild quartered-strength solution. (page 58). I did all that too.
Most problematic I find it to water all those cubes. It seems that some dry out too quickly and I can’t shake each single cubes off of excess water. I am really curious if I can use something like jiffy tablets (they are easier to handle, yes?) and then transplant them later into 10 cm x 10 cm rockwool cubes.
@legalcanada Do you use rockwool? Where did you read or hear it that there is no lime in the cubes?
I am wondering what ph the plant creates through its own processes? I think on the grodan site I did read that it is normal that the plant creates a higher ph in the medium. Anybody got any info about that?
maybe he means the ambient room temperature 26C? i wouldn’t water my plants with 80 degree water anyways… i germinate (and grow) in coco/perlite, but it’s also an inert media like rockwool, i generally feed around 350-500ppm right from germination and only time i use plain water is maybe the last couple waterings b4 harvest.
honestly i’ve only finished 2 crops so my method atm is K.I.S.S. i’m not too concerned with trying to maximize veg growth/speed by worrying about VPD, temperature, etc so i dont use heating pads, humidity domes, humidifiers etc
perhaps you could try watering from the botton, if there’s holes in the tray you could put it inside another tray filled with water and let em soak it up for 15-20 mins. actually after looking at your picture again maybe the light is also too strong now. i’m not sure if these are leaning over because theyre just too stretchy/weak or if they’re shying away from the light/heat.
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haha yeah, that is the video that I also saw.
Anyways I was using Cultilene instead of Grodan and there I did read that they were earlier at this stage.
The plants were not shying away. The stretched to the T5. Especially in the periphery. Now since long time there happens almost nothing. Some actually seem still to grow very minimally.
Day before yesterday, after not watering them three days (had the dehuey off, so the cubes dont dry out as quickly), I noticed that they were looking better. The leaves more upwards. Then I gave them 5.5 ph water with fertlizer. Next day plants were looking in a way so that I was thinking they look bad again. Leaves seemed to droop more.
I still not know what it is. Is it something in the cubes? In the water? Or the amount of water in the cubes?
Heating pad is off already since longer time.
Any idea?
i think they’ll prob all recover fine… stretch isnt 2 big of deal cause you can usually bury it when you transplant… ive never used rockwool though so idk if that works the same
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Once the 1" rockwool cubes are separated, they are a nightmare to keep evenly watered/not soaked. Especially when they are in the cell packs. If you are doing a bunch at once, I recommend filling seedling trays with a soilless mix. Sure it’s dirty, but it’s easier to see the dry ones and give them a sip without soaking the ones that don’t need it.
Otherwise the individual rockwool cubes need individual attention.
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If I got some time I will investigate what I could use.
How about the rockwool starter cubes for clones? Are they much better suited for that scenario? I plan to do clones after I got past the first seed and mother plant selection stage.
Yes, rockwool is my favorite media for clones.
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what temperature the roots like?
I got confirmation now from the manufacturer that there is no presoak or flushing of the cubes necessary and the influence of the stone wool on the ph is very small. If there is an increase in the ph, then it is by other factors, like the fertilizers in the water, the roots uptake and micro biological activity which have much more influence on the pH in stone wool substrates.
what soilless mix can you recommend?
i think i am trying it now with jiffy pellets and then transplant them to the rockwool cubes.
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I like Sunshine #4
Or, Pro-Mix HP with mycorrhizae, in a pinch.
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If I use jiffy pellets, what ph should water with?
If I put the jiffy pellets into the rockwool, what ph I would water then?
Any Idea?
Peat or coco?
Ok new try. Now with eazy plugs. They seem to buffer the ph better and also hold the water better. I did place them on top of the old plastic cubes of the rockwool plugs which I used before. So now the eazy plugs stand not in the water but the excess water can run off.
Also I changed the lights. I found somewhere an old 7 bulb lamp. Changed the bulbs. Distance to plants 8 inch. Ok? Anybody know what these additional reflectors are for? (See picture)
Also I am doing my own calmag now with calcium nitrate and magnesium sulfate. Ph 5.8
Seedling 2 days old. Root temperature at 26 degrees. Changed it now to 22. Humidity 60%
Somehow the CO2 device did go up to the maximum value. Because I worked in the rooms? Idk the real value, it maxes at 1994…
You soak the rockwool in 5.5pH but the waterings should be 5.8pH. That is too low.
Are they drying up or burning? I do not see any moisture! Looks to me like the rockwool was left unatended.
If i do it this way, i wash the rock wool in new pH’d water again before using, it is very alkaline, very much so, it will spoil the water and its pH if you let them sit in the water for too long. I do like 10 minutes in 5.5pH water and VOILA!
That would explain the overly dry rock, 1 inch plugs dry up fast.
I agree, please don’t be shy @SamandMax. I do not hope for a next time tho. Hopefully you can get it dialed in.
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They are growing very good now. Couple of days ago I lowered the lights until 0.4 to 1 inches to the leaves of the seedlings. Now no stretching, only leaf growth. Can you imagine that i would have to hang the lights so low? :-DDDD I did read to hang it 8 to 12 inches 
Not only one seedling did not sprout or grow. With the eazy plugs I water them every day.
When can I start feeding them? And how much percentage of full strength dosage?
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