Growing in 6x6x5.3” vidawool cubes, beginning of growth initial soak 5.5ph 1.2 EC calculated saturation to 67% field capacity, measuring media WC% and EC levels with Teros12. Dried back to about 50% and began irrigation injections, seemed that about half of the room was being overwatered and stunted growth dramatically so I cut irrigation and ignored media readings until I noticed plants recovering ~2 weeks. Now back to injections and my field capacity is seeming to be closer to 53% until I get heavy run off. Overnight dryback to about 38% requires 6 1 min injections spaced 15 mins apart to get up to 53% after lights on which produces 25% run off. Feel that my cubes aren’t becoming saturated correctly with injections considering my field capacity is about 10% lower than recommended and my run off is so heavy. Ended up pulling about half of the rooms cubes out and vegging plants much larger than usual to fill out canopy so that the stunted plants werent choked out by the larger ones.
Also, sub 20% WC in generative growth cycles is dangerously low and crop steering will be difficult without causing harm. Teros12 meter is placed in media toward drainage slope and at height as recommended. Any suggestions or similar experience to offer would be greatly appreciated
Quit focusing so much on the teros 12 readings and go back to growing plants based on tried and true methods. Don’t get me wrong, we have used teros 12s and zl-6s for years, they are great tools. Old school observation, measuring runoff, and knowing what to expect when are where I would start.
There are so many variables, you are going to have to experimentally establish many things including wilt point for each cultivar. As an example we steer dry generative, wet vegetative, dry generative in flower but you can’t really se the whole picture via teros 12 data only. Runoff, cube weight, and plant observations tell more of the story.
Also know that the stone wool you use makes a difference, as they all have different properties. And yes some stone wool products the field capacity changes, which is annoying as hell. We run a more expensive stone wool just for it’s repeatable water holding characteristics.
Check out caps Bean Basement, as some members there have been using teros sensors for years.
Hey this is a bit random and I’m not sure it’s even correct but I thought I remembered someone on IG who is involved with crop steering saying that if rockwool dries back too far it can “go hydrophobic” and not hold as much water as before.
I’m not really sure about this and I think I read it on a story so I can’t go find the info off hand.
I know that rockwool is naturally hydrophobic so that part fits.
I just tried to reach out to the person who I believe said this and will let you know if I hear back about it.
Does anyone else know anything about this?
If your let your rockwool dry below 30% it will be hard to get it to re saturate to what it was before.
The moisture holding capacity will naturally go down as the block fills out with roots usually about 60-65%.
How big are your plants? I can do 10’ tall tomatoes in 6" cubes with proper irrigation. How big is your root mass?
Have you thought about searching Google on the Growlink/FloraFlex/Aroya sites or here on Future for crop steering?
@Medicine.grower has an amazing crop steering thread here on Future and is a really solid dude.
I wonder if a surfactant would help? I wouldn’t add it in with plants only because I think it would choke the roots that were already grown out.
Just spitballing I guess, I don’t really see surfactants as additives anymore- might be a good reason
When I hand soak, I can achieve 67% field capacity and I get a ridiculous amount of run off, talking 50% runoff. With 2 .5gph emitter stakes per cube I cannot reach field capacity whatsoever and I still get a ridiculous amount of runoff. I’ve never had this issue before the response that cubes have gone hydrophobic makes sense.
We pay almost a dollar more per 6x6 cube to get the stone wool that we like. Other rockwool we trialed had bad problems with not rehydrating after drybacks. Others drained to quick/slow for our steering practices. We use hawthorne quick drain, your grow may need different stone wool properties…
https://www.hawthornegc.com/shop/product/grodan-pargro-quick-drain-stonewool
Edit: we tried surfactants, like yuca… My recommendation: pick the correct stone wool for your application instead of trying to band-aid with a surfactant. If you never dry back and make the substrate hydrophobic, you can run stone wools that we can’t, as drybacks are part of our plant stressor steering strategy for most cultivars.
You can try moving the sensor, I find after a while they won’t give an accurate reading anymore. Not saying this is the case here.
I keep hearing same responses, bad product. Anybody looking to transition to Rockwool steer clear of vidawool products. I’ll be spending more on the next reset for grodans cubes.
As others mentioned, if you dry back too hard you can significantly lower your field capacity. If it happens multiple times you’ll no longer be able to steer generatively. Anything below 35% is pushing it in rockwool. I’d suggest using .3gph emitters as well.
Gotta keep ‘em saturated!
Also, don’t do this. All irrigation, including any flushes should be done through your emitters. Hand watering will cause issues with channeling and also affect field capacity.
I’ve had the exact opposite experience with vidawool, we switched from grodan to vidawool and are experiencing less issues with it going hydrophobic.
I’ll second vidawool has been a great product for me. No issues with Grodan, I just get much better pricing on vida.
I’ll share my initial SOP.
Rinse blocks day before t-plant, rinse again with t-plant, allow heavy 1st dry back to root in. Should be 5-8 days probably depending on your environment. Now I push this initial dry back very low and chose to hand water fully back up, then place my drippers and do not push significant dry backs anymore, you do not need to in wool to get the EC response needed. Remember its not the dry back we are really concerned about vs the EC levels being manipulated with dry back as a tool to do it. There are other ways to manipulate EC as well, don’t rely only on dry back.
I’m curious how big of an issue you had with various brands of rockwool “going hydrophobic”.
Was it such a serious issue you almost lost a run or was it just an annoyance and inhibited you from using crop steering techniques.
I have been studying up more on crop steering and it seems like rockwool is less forgiving than coco but coco can have even bigger inconsistency issues and still requires dealing with the media where as rockwool you can just pull out and send to the recycler (or landfill).
Rockwool seems like much better ability to crop steer but much easier to lose a crop, would you agree with that?
I think if your careful you won’t have an issue with rockwool, the only thing if you mess it up is that you won’t be able to have nice long dry backs. Worst case is you’ll be steering more vegative then you’d want.
It’s seeming to be pretty stable now, but during the beginning stages from transplant through first week cubes were so waterlogged I was forced to dry back to extreme levels after killing off nearly 70% of the room to root rot. When remaining healthy plants had set root and were ready for irrigation I was getting about 50% run off in order to maintain 67% field capacity. Now on week 4 of flower cubes are easy going but what a waste. Usually run 1x1’ footprint per plant and I was forced to triple that in order to fill canopy and not throw room out and restart. Nearly a month of veg, what a waste of electricity! Lol
Hey I’m just curious if anyone has experienced the rockwool issue that’s being talked about on IG by poetryofplants?
Sounds like it might be an issue with the wetting agent and/or aluminum toxicity.
The plants being effected look like ferns.
Do you know the brand of rockwool?