Rockwool Advice

So these two plants are about a month old and my rootzone looks terrible and growth is very stunted. I don’t understand why my rootzones won’t grow out or why my deficiencies persist. I’ll leave my full rundown as well as pictures. Any steps in the right direction would be so so appreciated.

Strain: Passion #1 (Dutch Passion)
Medium: Hugo Blocks
Water Source: RO Filter 0EC/0PPM

Using General Hydro Nutes
Calmag 10ml per Gal
Micro 10ml per Gal
Veg 15ml per Gal
Bloom 5ml per Gal
Rapid Start 1/2ml per Gal

The EC comes out at about 3.4 so I dilute with RO to the EC: 1.8-2.2 range and then PH adjust to 5.7-5.9
Water temp steady at about 22°C (whatever room temp is really)

There’s a constant stream of fresh air coming into my tent through ducting. I don’t have a Co2 meter.

Average Room Temp At Canopy Level During Lights On: 26.5°C-30.5°C
Average Humidity Lights On: 47%RH-62%RH
Leaf Temp: usually 2°C (+/- 0.2°C) Lower then Average Room Temp.

Humidity is my biggest fluctuation. Even with a humidifier I’m having to vent fresh air in and stale hot air out to keep the temp low enough. Regardless, within peak conditions of these parameters my VPD still falls within an acceptable range.

The first couple feedings I soaked the cube till saturation in a low EC concentration. As of the last 3-4 feedings I’ve been top feeding, waiting for a runoff of 30-50%. As of week 4 (since sprout) I’m now having to water about every 2 days before they cube feels very light or after about 3 days the plant will show signs of wilt.
I have floracaps on to even-out the water distribution.

-How do I get my roots to grow out from the middle? In soil I’d water around the edges but rockwool just soaks...

-How is my plant not getting enough when it’ll burn above 2.2EC but show these sign at anything below. Also it’s on average too warm and sometimes dry to push the EC too high. That’s where I think my salt build up is coming from. At least I think??

Any advice in just the right direction would be so helpful, I seem to be off my game. For contrast I’ve included my peppers grown in soil in the same tent and started a week later in 3gal pots.

I included my feeding calendar for May (April just has too much shit on it) ROC is RockWool fallowed by the PH first the EC for that feeding. PEP is the peppers but they’re doing pretty alright there in soil so I wouldn’t worry.

Thanks you all so much!

@thenotsoesoteric grows some amazing plants in rockwool and is a very seasoned grower.
He might be available to answer your questions.

I only use rockwool when I have to take more than 20 cuttings. I don't actually grow in it so I'll wait to see if you get some assistance from those that do.

Or you could do a search for rockwool. That would at least get you some info from growers who use that substrate successfully.

I'm not gonna lie, there is a learning curve when actually growing ingredients rock wool.

You have to balance the wetness with the level of salts in the cubes. So my first advice is cut that fertilizer down to
2.5 micro
2.5 bloom
No grow
No calmag, you're in rock wool not coco so it's not needed and is just excess salts.

Flush your cubes good and let them dry out a bit then go to a wetting ratio that keeps the plants happy but doesnt go nuts.

Jungle boys water their rock wool plants by the milliliter! So there is a method you just gotta figure out but in my opinion you ppm/ec is way too high.

thenotsoesoteric said:

I'm not gonna lie, there is a learning curve when actually growing ingredients rock wool.

You have to balance the wetness with the level of salts in the cubes. So my first advice is cut that fertilizer down to
2.5 micro
2.5 bloom
No grow
No calmag, you're in rock wool not coco so it's not needed and is just excess salts.

Flush your cubes good and let them dry out a bit then go to a wetting ratio that keeps the plants happy but doesnt go nuts.

Jungle boys water their rock wool plants by the milliliter! So there is a method you just gotta figure out but in my opinion you ppm/ec is way too high.

Click to expand...

Really eh? No Grow or Calmag even though I’m deep vegging? And you think my leaf yellowing is excess and not deficiency??

Also thanks for the jungle boy’s recommendation Im definitely going to check that out right now. If there’s an exact ml count per watering that’s amazing. Thanks for the quick reply dude!