Disillusioned with rockwool

[Boricuaman]

I have started seed in rock wool. The process seems so much slower then dirt. My plants(4 weeks) are very small right now. My first time doing this and I am still top feeding them. I put three into a 4x4 rockwool cube. I put germinated seeds in the 1.5x 1.5. and they are very slow to show their head. One showed it's head so I put it under the lights with the 4x4 plants, the leaves opened but the stem did not grow. maybe too close to the lights so I adjusted and it hasn't moved for about a week. I am a new grower and wanted to do a hydro grow(ebb & flow) because I may not be able to tend to my plants for several days so I need sort of an auto pilot thing here. But I haven't even set up the ebb& flow tray yet. Is this normal and do I lack patience? I put a kush seed in a mix of MGrow potting soil, peat moss, perlite, vermiculite, and threw castings from my worm bin too. I've been giving it fish emulsion and the thing is huge. I transferred it to a 6 gal. spackle bucket. I've tied down about 5 branches. This is an outdoor grow. I did this for the hell of it. I do however really want my indoor grow to succeed. I have spent a lot of $. Any tips of whether I am doing something wrong or if this is normal would be appreciated.

 

[Skylinedive]

I'm on my first grow so take anything I say with a grain of salt.

I'm using rockwool cubes in an enclosed propagator. The temp inside the propagator is steadily between 77F-80F (24C-26C rounded) with 50% humidity. I'm using two T5 LED cool spectrum lights running 24/0. My water purity is 62 ppmi. I do have a reverse osmosis water purifier but I just haven't messed with it yet. My PH is 5.5-6.0. I am currently on day grow day-5 of my first grow.

I soaked my rockwool in PH-set water for a couple hours before seeding. I placed them only a few cm's into the cube and pinched the opening shut. They seem to be doing great so far.

 

[Boricuaman]

Beautiful! They look healthy. What strain is it? One of mine came out of the wool, but the other one hasn't yet. It's been almost a week. Then one I planted before them opened it's leaves but stayed just above the wool and has stagnated. Keep doing what your doing. I will keep them in the propagator.

 

[Boricuaman]

Did you just drop the seed in there or did you soak them overnight? I soaked mine overnight and then put them in a wet paper towel overnight. Then I put them in the 1.5" grow blocks. I think the seed hole is too deep or could I be over thinking this? I soaked the blocks in a nutrient/water solution with a ph of 5.6 I believe.

 

[Weaselcracker]

Rockwool out of the box can have a high ph like over 8, so should be soaked for a while. The only other problem I've had with it is- it can retain too much water. If it is totally saturated-there's a good chance of a seed or seedling rotting. 50% saturated or even less would be a more comfy home for a plant.

 

[vastok]

Rockwool has a tendency to hold way too much water, tho many are encouraged to squeeze some out, its still too much, best by far is perlite, also great as an aerator in most soils

 

[Boricuaman]

I've gotten mixed signals. I had three larger seedlings in 4" blocks in another location in a propagator tray without a dome but sitting on a heating mat. I saturated them with nutrient solution and when I returned (4 days later) one was practically dry and the leaves dying. But the little ones with the heads just coming out of the soil may be too wet. I only have a total of six now. 3 about a month in and 3 a week.

 

[Weaselcracker]

Larger seedlings will be better able to deal with the water, also plenty of water will evaporate using a seedling mat for heat, and no dome. Rockwool doesn't have an overwatering issue with larger size plants - but for clone size cuttings, and sprouting seeds, it can. It's not that it won't dry out eventually, just not fast enough for the little ones, who may rot in the meantime.