water soapy after soaking rockwool?

CaliWorthington

CaliWorthington

Well-Known Member
I thought I'd try growing in 6" rockwool blocks with FloraFlex caps on my drip tables. I've always used soil, soilless peat mix, coco or hydroton before. I followed the instructions and soaked a couple blocks in pH 5.5 water for 30 minutes. Afterwards, the water was really soapy looking, sudsy on top. Is this normal? Is that the dissolved lime? These are not grodan brand blocks, they're green diamond.

I thought this would be less work than usual, but I can only soak a few blocks at a time. It looks like I'll have to make a fresh batch of pH 5.5 water for every couple blocks that I soak. Also it takes like 10 minutes for each block to drain. That's a long time to stand there holding them. I might scrap the rockwool idea and go back to something else for this grow.
 
Airwalker16

Airwalker16

Well-Known Member
CaliWorthington said:
I thought I'd try growing in 6" rockwool blocks with FloraFlex caps on my drip tables. I've always used soil, soilless peat mix, coco or hydroton before. I followed the instructions and soaked a couple blocks in pH 5.5 water for 30 minutes. Afterwards, the water was really soapy looking, sudsy on top. Is this normal? Is that the dissolved lime? These are not grodan brand blocks, they're green diamond.

I thought this would be less work than usual, but I can only soak a few blocks at a time. It looks like I'll have to make a fresh batch of pH 5.5 water for every couple blocks that I soak. Also it takes like 10 minutes for each block to drain. That's a long time to stand there holding them. I might scrap the rockwool idea and go back to something else for this grow.
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Rockwool stays too wet. It'd be a decent medium for strongly vegging plants with vigorously growing root systems that can use up the water they hold. But for anything small, it's a bad idea.
 
CaliWorthington

CaliWorthington

Well-Known Member
Airwalker16 said:
Rockwool stays too wet. It'd be a decent medium for strongly vegging plants with vigorously growing root systems that can use up the water they hold. But for anything small, it's a bad idea.
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Interesting. I have noticed that some people over water their rockwool. Supposedly it has excellent aeration, if you let it dry out enough between watering.

But it is more work that I had thought. I could get the floraflex pots and put coco in them, which is how they're supposed to be used. That way I can still use these floraflex caps. I've already modified my pvc watering spines to floraflex bubblers too.

I think I've been getting some lockout issues from using RO water and adding cal mag every time in coco, though. I'll try going back to coco specific nutes (H&G Cocos AB instead of Bloom Yellow Bottles Euro AB), and cut the cal mag some after they get established. I have to use RO water, there's too much minerals in the water here otherwise.
 
Airwalker16

Airwalker16

Well-Known Member
CaliWorthington said:
Interesting. I have noticed that some people over water their rockwool. Supposedly it has excellent aeration, if you let it dry out enough between watering.

But it is more work that I had thought. I could get the floraflex pots and put coco in them, which is how they're supposed to be used. That way I can still use these floraflex caps. I've already modified my pvc watering spines to floraflex bubblers too.

I think I've been getting some lockout issues from using RO water and adding cal mag every time in coco, though. I'll try going back to coco specific nutes (H&G Cocos AB instead of Bloom Yellow Bottles Euro AB), and cut the cal mag some after they get established. I have to use RO water, there's too much minerals in the water here otherwise.
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You mixing calmag into the RO very first?
 
JohnDee

JohnDee

Well-Known Member
CaliWorthington said:
I thought I'd try growing in 6" rockwool blocks with FloraFlex caps on my drip tables. I've always used soil, soilless peat mix, coco or hydroton before. I followed the instructions and soaked a couple blocks in pH 5.5 water for 30 minutes. Afterwards, the water was really soapy looking, sudsy on top. Is this normal? Is that the dissolved lime? These are not grodan brand blocks, they're green diamond.

I thought this would be less work than usual, but I can only soak a few blocks at a time. It looks like I'll have to make a fresh batch of pH 5.5 water for every couple blocks that I soak. Also it takes like 10 minutes for each block to drain. That's a long time to stand there holding them. I might scrap the rockwool idea and go back to something else for this grow.
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Can't find anyplace to set it down to drain? lmoa Maybe skip the rockwool. Don't know what the suds are about...I use Grodan
 
CaliWorthington

CaliWorthington

Well-Known Member
JohnDee said:
Can't find anyplace to set it down to drain? lmoa Maybe skip the rockwool. Don't know what the suds are about...I use Grodan
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Well it was the first two blocks I'd ever soaked, and wasn't right next to the drip tables, so no. When you tilt them so they drain from one corner, it's quite a bit of water. If I was to soak any more blocks, I'd build a contraption with an angled grate they can sit on while they drain...forever.

So no suds huh? Maybe this is bogus rockwool. It smells a bit like dirty water after soaking too. I don't recall the little grodan clone blocks I've used ever having any smell at all.
 
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JohnDee

JohnDee

Well-Known Member
CaliWorthington said:
So no suds huh? Maybe this is bogus rockwool. It smells a bit like dirty water after soaking too. I don't recall the little grodan clone blocks I've used ever having any smell at all.
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Well just do like I do when I reuse coco. I just keep rinsing it till the water comes out clean and low ppm. Whatever's in the cube...your plant probably won't like it.
JD
 
CaliWorthington

CaliWorthington

Well-Known Member
JohnDee said:
Well just do like I do when I reuse coco. I just keep rinsing it till the water comes out clean and low ppm. Whatever's in the cube...your plant probably won't like it.
JD
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Yeah maybe I'll rinse those blocks a second time and see if more suds come out. The smell was probably just inherited from the brute reservoir having some funky old chiller water in it recently.

I'll get a proper brand name rockwool block to compare to these, while I'm buying those floraflex pots at the hydro warehouse. I can run both coco and rockwool on the same drip system, until the watering schedules diverge, that is.
 
JohnDee

JohnDee

Well-Known Member
CaliWorthington said:
Yeah maybe I'll rinse those blocks a second time and see if more suds come out. The smell was probably just inherited from the brute reservoir having some funky old chiller water in it recently.

I'll get a proper brand name rockwool block to compare to these, while I'm buying those floraflex pots at the hydro warehouse. I can run both coco and rockwool on the same drip system, until the watering schedules diverge, that is.
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I bid on a lot of rockwool at an auction. Won it. I have 4 cases of various Grodan block sizes. I'm toying with the idea of putting a big momma 8" block into a Waterfarm rig. Fits perfectly...but would have to hand water. Never a shortage of rockwool around here.
JD
 
CaliWorthington

CaliWorthington

Well-Known Member
JohnDee said:
I bid on a lot of rockwool at an auction. Won it. I have 4 cases of various Grodan block sizes. I'm toying with the idea of putting a big momma 8" block into a Waterfarm rig. Fits perfectly...but would have to hand water. Never a shortage of rockwool around here.
JD
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Nice rockwool stash. Those 8" blocks must be massive. If I was running the deeper ebb n' flow tables, I would put these blocks on there and flood it to soak them like everyone else. I've got the low tide botanicare drip tables in my room though, so I have to soak them in something else. Come to think of it, I've got an ebb n' flow tray I'm not using. I should dig it out and use that for soaking next time.
 
JohnDee

JohnDee

Well-Known Member
CaliWorthington said:
I should dig it out and use that for soaking next time.
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Bingo...there ya go. Over in the EU and especially in Amsterdam with that low salty land...the do lots of commercial greenhouse grows for veggies, But almost always top drip. I am too leary of toxic salts accumulating to use it flood and drain.
JD
 
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