ProMix HP

Hey all, I know most of you won’t recognize me as I’ve been out of the game for about 13 years now. But I am back and trying to get growing again.
My problem is ProMix. I am having nothing but PH issues using this medium. I have never used it and seen people give good reviews, but I can’t stop my soil PH dropping to 5 and below which has killed my prized original Blue Cheese clones, and is now killing my sativa mystery. Is this stuff really garbage, or have I been gone so long I’m making rookie mistakes? I’ve never used this medium, and I feel part of the issue was following Promix’s advice and PH’ing around 5.8. That was a mistake! But even PH’ing to 6.5 after getting the soil back to semi normal, it’s going straight back down to 5 and this lockout has occurred yet again. I’m at my wits end and ready to throw the rest of the bale in the trash! Any advice on this?

If that's the drainage waste you're measuring, you can expect the waste to be slightly acidic compared to your input, being a peat based mix.

How often is it getting watered?
Pot size?
How much water at a time?
How much waste?
How well is it draining?

Might it be staying a bit soggy or damp?
Sulphur + consistently soggy or wet media = increased acidity.

That left over bale should still be usable. I'd add more perlite to it, so it has more drainage.
Or, if it really is too acidic you could add lime. Truthfully, I think adding more drainage would work just as well.

Also what's your input EC?
A picture or two would help.

I run promix and I use well water at 8.0
No ph issues
The peat lowers the ph on its own

BongerChonger said:

If that's the drainage waste you're measuring, you can expect the waste to be slightly acidic compared to your input, being a peat based mix.

How often is it getting watered?
Pot size?
How much water at a time?
How much waste?
How well is it draining?

Might it be staying a bit soggy or damp?
Sulphur + consistently soggy or wet media = increased acidity.

That left over bale should still be usable. I'd add more perlite to it, so it has more drainage.
Or, if it really is too acidic you could add lime. Truthfully, I think adding more drainage would work just as well.

Also what's your input EC?
A picture or two would help.

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I’m actually using a soil tester to get my results. Everything is good on my end, I’ve had well over 100 grows in the past, so it’s not like I don’t know what I’m doing. I used a special compost mix in the past, but sadly that farmer is no longer around and his kids sold off the property. So I looked up what I can use and this kept coming up. I water every two days in a 15G pot. She’s huge and drinks a lot and we have hot dry summers where I live. Always add extra pearlite so I know drainage isn’t an issue, and I always let my plants tell me they needs a drink. I really don’t think pictures will help when it’s my soil PH that keeps dropping. I guess I’ll just PH a little higher, maybe 7, add some dolomite, and see how things go from there. Oh, and I am outdoor, but I don’t think that has a role in this

homegrownboy said:

I’m actually using a soil tester to get my results. Everything is good on my end, I’ve had well over 100 grows in the past, so it’s not like I don’t know what I’m doing. I used a special compost mix in the past, but sadly that farmer is no longer around and his kids sold off the property. So I looked up what I can use and this kept coming up. I water every two days in a 15G pot. She’s huge and drinks a lot and we have hot dry summers where I live. Always add extra pearlite so I know drainage isn’t an issue, and I always let my plants tell me they needs a drink. I really don’t think pictures will help when it’s my soil PH that keeps dropping. I guess I’ll just PH a little higher, maybe 7, add some dolomite, and see how things go from there.

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Lots of folk here go by their waste for pH. Was giving you benefit of doubt. Just had to ask the question.

Have you checked the pH using your soil tester before you water, not after?

If it really is acidic, then add dolomite as you say, see how things go.

GL.

homegrownboy said:

Hey all, I know most of you won’t recognize me as I’ve been out of the game for about 13 years now. But I am back and trying to get growing again.
My problem is ProMix. I am having nothing but PH issues using this medium. I have never used it and seen people give good reviews, but I can’t stop my soil PH dropping to 5 and below which has killed my prized original Blue Cheese clones, and is now killing my sativa mystery. Is this stuff really garbage, or have I been gone so long I’m making rookie mistakes? I’ve never used this medium, and I feel part of the issue was following Promix’s advice and PH’ing around 5.8. That was a mistake! But even PH’ing to 6.5 after getting the soil back to semi normal, it’s going straight back down to 5 and this lockout has occurred yet again. I’m at my wits end and ready to throw the rest of the bale in the trash! Any advice on this?

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For starters Pro mix is not soil It is a soilless medium Have been using it many yrs It likes dry-wet with good runoff not sure what you use for ferts but mixing any kind of organic stuff trying to treat it like soil does not work. I consider it more like hydro I control what goes in each watering.

BongerChonger said:

Lots of folk here go by their waste for pH. Was giving you benefit of doubt. Just had to ask the question.

Have you checked the pH using your soil tester before you water, not after?

If it really is acidic, then add dolomite as you say, see how things go.

GL.

Click to expand...

To be honest no. I just bought a BlueLabs soil tester a few weeks back, and JUST got the soil back up to 6.3 last week. Now I’m back down to 5 and slamming my head against a wall. I feel like such a rookie when I have tons of grows under my belt and never run into these kinds of problems before until I started using this medium.

thumper60 said:

For starters Pro mix is not soil It is a soilless medium Have been using it many yrs It likes dry-wet with good runoff not sure what you use for ferts but mixing any kind of organic stuff trying to treat it like soil does not work. I consider it more like hydro I control what goes in each watering.

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I was and still am for the sativa mystery, using AN Jungle Juice. For the autos in the tent, I’m using GG AP and PB, and I am having zero issues watering with dechlorinated UN-PH’d tap water. I always water till runoff when using salt ferts, and my PPM and EC have been generally good. I’m almost wondering if it’s the nutes, but my sativa hasn’t shown any signs until now going into week 2 of flower, whereas the clones just showed signs and died off in a week, weeks ago. I’m at a stand still and done everything people have suggested, treated it like hydro, treated it like soil, tried the in between side of it, and still, dropping rapidly and locking out immediately.

thumper60 said:

For starters Pro mix is not soil It is a soilless medium Have been using it many yrs It likes dry-wet with good runoff not sure what you use for ferts but mixing any kind of organic stuff trying to treat it like soil does not work. I consider it more like hydro I control what goes in each watering.

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Promix hp user. You are 100% correct. It's closer to coco than many people realize, just a bit slower. I use GH ferts with great results in promix hp. I wouldn't recommend organic amendments. I differ with you only on dry/ wet, promix needs even moisture, if it starts to dry out, you get imbalances and it becomes difficult to easily remoisten. I water to runoff every other day with full strength nutes.

shnkrmn said:

Promix hp user. You are 100% correct. It's closer to coco than many people realize, just a bit slower. I use GH ferts with great results in promix hp. I wouldn't recommend organic amendments. I differ with you only on dry/ wet, promix needs even moisture, if it starts to dry out, you get imbalances and it becomes difficult to easily remoisten. I water to runoff every other day with full strength nutes.

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Care to share your regime? I’m using the Lucas Method with the JJ. I’ve tried already to treat it like hydro, but that’s what started the whole lockout and low medium PH and killed my clones. I followed Promix’s guide, and that ended up costing me hundreds of dollars in clones! So to me, treating like hydro is where this got me. Now I’m having issues with my sativa and low PH because I transplanted into new medium from the bale and now I’m having the exact issues as before, and I was PH’ing to 6.5 with no issues until I added the new bale when transplanting. All I know is I don’t like it, and it has so far costed me a lot of time and money all for nothing!
As for organic, I’m having no issues with the autos in this medium, so I am just totally baffled especially when some of you are saying not to use amendments, I’m having great luck!

homegrownboy said:

As for organic, I’m having no issues with the autos in this medium, so I am just totally baffled especially when some of you are saying not to use amendments, I’m having great luck!

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Well, what's different about it? What amendments have you used? Have you checked the pH for those ones?

I think lime is the last thing you should consider. Really should be the last course of action.
Should already be buffered adequately.
Though, I'll give you benefit of doubt.
I assumed overwatering at first.

Maybe you just got a crap bale?
Shit happens sometimes.

BongerChonger said:

Well, what's different about it? What amendments have you used? Have you checked the pH for those ones?

I think lime is the last thing you should consider. Really should be the last course of action.
Should already be buffered adequately.
Though, I'll give you benefit of doubt.
I assumed overwatering at first.

Maybe you just got a crap bale?
Shit happens sometimes.

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I’m using Gaia AP and PB at the recommended rate of 3tbps per gallon for amending at a 70/30 ratio. Next feed will be a top dress of 50/50. I think it could possibly be the nutes now that I think about it. If my medium is at 6.4 in the organic and I’m having zero issues, it just may be the food. Either way I’m flushing the mystery seed until I get a read out of 6.3-6.5 and starting over again. My last 2 feedings also may have been a bit high at 1800PPM, compared to the 1600 is was giving before. Thought she could use a little higher going into flowering. Maybe I was wrong. Hopefully I can get this figured out soon cause I’m very curious to see what she produces, got a LOT of main colas from topping and LST, I think I counted 12 or 13 last time. I also thought maybe I was overwatering, but I generally let my plants tell me they are thirsty so I don’t oversaturate the main rootball. Oh well, I thought maybe people would have some tips as to what the issue is, but it seems everyone is just as stumped as me lol.

homegrownboy said:

I think it could possibly be the nutes now that I think about it. it just may be the food. My last 2 feedings also may have been a bit high at 1800PPM, compared to the 1600 is was giving before. Thought she could use a little higher going into flowering. Maybe I was wrong.

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That says a lot to be completely honest. You're up over 3.0 EC, that's way high.

BongerChonger said:

That says a lot to be completely honest. You're up over 3.0 EC, that's way high.

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She really liked 1600 that’s for sure. Shouldn’t have jumped.

homegrownboy said:

She really liked 1600 that’s for sure. Shouldn’t have jumped.

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Even 1600.
What ppm scale are you using?
1600ppm @700 scale, is still 2.4 EC, I think.
That's nothing to scoff at.

Back off a bit.
Make it more like 1.8 - 2.0 EC @ desired pH.
Get good runoff. See how it goes.

BongerChonger said:

Even 1600.
What ppm scale are you using?
1600ppm @700 scale, is still 2.4 EC, I think.
That's nothing to scoff at.

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I’ve had plants take 2000 and thrive. Just depends on the strain and genetics really. She was a little slow at growing until I upped her dosage from 1100-1600 and then she took off!

You're pumping a shitload of organic material into a sterile mix, that may or may not have the microbial activity to use it.
My shot in dark guess is all that stuff is breaking down into high amounts of ammonium and that is why your pH is in the gutter.

All Purpose | Gaia Green Organics

7CardBud said:

You're pumping a shitload of organic material into a sterile mix, that may or may not have the microbial activity to use it.
My shot in dark guess is all that stuff is breaking down into high amounts of ammonium and that is why your pH is in the gutter.

All Purpose | Gaia Green Organics

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Ahh, nope. My organic side is fine. It’s my salt nutes side that’s having issues when using new Promix.
My autos are in PM and GG amended in.
My clones and mystery seed are being fed AN Jungle Juice. That’s where my problems arise. Nothing to do with the organic side.

homegrownboy said:

Ahh, nope. My organic side is fine. It’s my salt nutes side that’s having issues when using new Promix.
My autos are in PM and GG amended in.
My clones and mystery seed are being fed AN Jungle Juice. That’s where my problems arise. Nothing to do with the organic side.

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Hmm.....I'll add one more vote for a shit batch of Promix then.

I've run most of the big name peat mixes, Promix, Berger, Lambert, Sunshine and usually just dump about 1.2EC through them start to finish without any real issues.