Tips On What To Add To Promix? ProMix Amendment Recipe

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Jimster

Jimster

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promix bales have 2 kinds of lime added. Calcitic and dolomite. With any reasonable tap water the ph of the medium will self buffer.
I use moderate alkalinity well water with 150 ppm mineral content and 8.0 ph and never need to adjust the ph of water only or a nute mixture.
I echo your observations. I've used Promix for over 3 decades and I bought my 1st Ph meter last year, as well as a chemical Ph test. They both indicated right around 7. I use tap water exclusively, which is medium hardness. Promix has worked very well for me over the years, but perhaps the local water conditions keep things in balance. It DOES shrink away from the bucket edges towards the finish, but not enough to cause any problems other than not holding as much water, which might be decreased by the near root bound condition at the end.
 
MIMedGrower

MIMedGrower

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I echo your observations. I've used Promix for over 3 decades and I bought my 1st Ph meter last year, as well as a chemical Ph test. They both indicated right around 7. I use tap water exclusively, which is medium hardness. Promix has worked very well for me over the years, but perhaps the local water conditions keep things in balance. It DOES shrink away from the bucket edges towards the finish, but not enough to cause any problems other than not holding as much water, which might be decreased by the near root bound condition at the end.


Only reason i switched back to ocean forest and recently mother earth groundswell is its easier for me to water only through veg with plants constantly at different stages.
 
Dirtbag

Dirtbag

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I echo your observations. I've used Promix for over 3 decades and I bought my 1st Ph meter last year, as well as a chemical Ph test. They both indicated right around 7. I use tap water exclusively, which is medium hardness. Promix has worked very well for me over the years, but perhaps the local water conditions keep things in balance. It DOES shrink away from the bucket edges towards the finish, but not enough to cause any problems other than not holding as much water, which might be decreased by the near root bound condition at the end.
A big part of that shrinkage and reduced water holding capacity near the end is because it comes precharged with a surfactant which only works for a month or two tops. Promix actually recommends recharging it with surfactant when it starts doing that if I recall correctly. I usually apply a surfactant called revolution to my promix once a month or so and it never shrinks or loses its water holding capacity.
 
Jimster

Jimster

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A big part of that shrinkage and reduced water holding capacity near the end is because it comes precharged with a surfactant which only works for a month or two tops.
The shrinkage that I get is pretty small...topping the buckets up to near the top mitigates the ptoblem. There is a little pullback along the inside of the bucket at the bucket/soil boundary, but I've seen nearly every medium do that to some degree. Keeping things well watered also helps to prevent it. I used to sprinkle about a quarter teaspoon of laundry detergent in with the Promix/compost mixture, but it was mostly for hydrating the Promix and not for ongoing maint. I'll keep this in mind!
 
MIMedGrower

MIMedGrower

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The shrinkage that I get is pretty small...topping the buckets up to near the top mitigates the ptoblem. There is a little pullback along the inside of the bucket at the bucket/soil boundary, but I've seen nearly every medium do that to some degree. Keeping things well watered also helps to prevent it. I used to sprinkle about a quarter teaspoon of laundry detergent in with the Promix/compost mixture, but it was mostly for hydrating the Promix and not for ongoing maint. I'll keep this in mind!



I just scratch the surface up before each watering and the gap keeps getting filled in. Ocean forest hardens up as well as shrinks. And rejects water. This fixes all that.
 
Jimster

Jimster

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I just scratch the surface up before each watering and the gap keeps getting filled in. Ocean forest hardens up as well as shrinks. And rejects water. This fixes all that.
I use the hose to circle the inner bucket and stuff falls into the cracks, if there are any. It's sort of like finding something in a toilet bowl when you are taking a leak...you can't help but aim for it!
 
Dirtbag

Dirtbag

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You guys would probably both benefit from a little non-ionic surfactant right as they go into flower. Most grow store carry it and you can buy it online.
 
MIMedGrower

MIMedGrower

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You guys would probably both benefit from a little non-ionic surfactant right as they go into flower. Most grow store carry it and you can buy it online.


I start my final pot about 5 days before 12/12. I like a very dry cycle. I never saw it as a problem. Just scratch the dirt with a moisture probe tip. Or my fingers.

Maybe if it continued to dispell water...
 
Dirtbag

Dirtbag

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Yeah, I mean it's not necessary. i grew for over a decade with no real issues before i started treating my promix in flower. But I certainly find it helps the water penetrate the media much better, and it greatly improves drainage. It helps prevent the umbrella effect just below the crown of the root ball. Yucca works good too as an organic surfactant.
 
MIMedGrower

MIMedGrower

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Yeah, I mean it's not necessary. i grew for over a decade with no real issues before i started treating my promix in flower. But I certainly find it helps the water penetrate the media much better, and it greatly improves drainage. It helps prevent the umbrella effect just below the crown of the root ball. Yucca works good too as an organic surfactant.


Im still carefully hand watering with a cup. I pour a few evenly around the pots and wait 10 min or so. Then the rest to runoff. I dont see the problems.
 
Dirtbag

Dirtbag

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Im still carefully hand watering with a cup. I pour a few evenly around the pots and wait 10 min or so. Then the rest to runoff. I dont see the problems.

You know what they say, if it ain't broke dont fix it.

A lot of my growing has been in 10 gallon pots using promix, with 3-4 weeks veg time in those pots before flip was normal so I would get pretty obvious penetration issues midway through flower. A visible crust forming and sides pulling away from the pot etc. Surfactant helped. But like I say if it aint broke. It's just another tool in the toolbox.
 
MIMedGrower

MIMedGrower

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438
You know what they say, if it ain't broke dont fix it.

A lot of my growing has been in 10 gallon pots using promix, with 3-4 weeks veg time in those pots before flip was normal so I would get pretty obvious penetration issues midway through flower. A visible crust forming and sides pulling away from the pot etc. Surfactant helped. But like I say if it aint broke. It's just another tool in the toolbox.


Like they say. Lots of ways to skin a cat.

They shouldnt say that horrible shit.

;-)
 
C

CocoFun

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This is an old thread but I know people still see these so I do throw my 2 cents in when NECESSARY.
Everyone talking about pH problems, STOP ADDING FRICKIN LIME!!!!! Just pH your water correctly, occasionally check a little runoff. And adjust the water you're putting in. Stop this lime stuff, the more crap you add to adjust things the more you have to adjust. PH YOUR WATER, ADJUST YOUR WATER. Not your medium.
 

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