Promix hp users, I'd appreciate your input and advice.

Hello all. This is gonna be long, but I need to pick your wonderful brains so stick with me.

Going to be doing an indoor winter run in my 2x2 (partially to help heat my room. True story.) and I want to hear from folks who currently or previously had success with promix.

I've only used it twice. Once years ago I ran it as a base medium for a half assed 'organic' run. The second was recently when I transplanted to it to save a crashing plant in bad soil. Fed that some floranova and calmag i had laying around and that plant recovered beautifully. So yeah, limited experience with the medium.

On to my questions.. I will not be amending the promix. Maybe a future grow.
My options for this grow are
1.) sterile, chelated nutrients (think GH trio or equivalent dry nutrient)

2.) 'organic' bottled nutrients intended to work better with active biology in the root zone.

Again, not going to be amending the promix this run, I want fairly precise control over my inputs for this poject. So I'm torn between those options and I'd like to know what has worked better for you all.

Second question.. I have been a firm advocate of the addition Si to nearly all hydroponic feed programs and I'm just wondering about your experience on its use in this medium in terms of need, efficacy, feed strength and frequency etc etc.

Lastly I'd add that I'm open to any tips and recommendations on getting the most out the medium. Watering frequency, feed strengths at various growth stages, optimal pH.... its all welcome. I've done a lot of reading but experience is invaluable.

For anyone who is made it this far i have 1 more question to pose..
as stated this is a 2x2 space (used to be a mother plant tent) with anywhere from 135 to 260 watts of HLG QBs as needed, and I'm trying to decide between doing 2 plants in 3 gallon pots or 1 plant in a 5 to 7 gallon pot? I've got to get this project rolling and my brain is too tired for more decisions.

This is what fucking happens when I post at 5am..
Thanks in advance for any input and sorry it took me 15 pages to get to the end.

1 plant in a 7 gallon properly trained would yield as much if not more than 3 smaller plants the only drawback is if it gets sick and dies you have no backup the promix on its own is fine may i suggest adding a bit of bone meal' earthworm castings and or bat guano maybe a couple cups of perlite anyways thats how i did my promix then only water and once a week a little molasses until flower then just bloom nutes as directed also let the medium dry out between waterings in a 7 gallon pot start with a full gallon then wait 2 days then about a half gallon a day thats what i did and i got 18 ounces with a 400 watt hps i since upgraded to 600

osowhom said:

1 plant in a 7 gallon properly trained would yield as much if not more than 3 smaller plants the only drawback is if it gets sick and dies you have no backup the promix on its own is fine may i suggest adding a bit of bone meal' earthworm castings and or bat guano maybe a couple cups of perlite anyways thats how i did my promix then only water and once a week a little molasses until flower then just bloom nutes as directed also let the medium dry out between waterings in a 7 gallon pot start with a full gallon then wait 2 days then about a half gallon a day thats what i did and i got 18 ounces with a 400 watt hps i since upgraded to 600

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Thanks for the input! The watering tips in particular are helpful as my last run in promix was with blumats so I didn't learn much about hand watering them.

The only problem I find with PM/HP is that it initially is on the low side of the pH range, my last 3 bricks / bags averaged out to pH 6.1, and for a peat based mix that is way to low, so I always add dolomite lime to get my final mix up to pH 6.4 - 6.6. For a 2.8 cf bag, I add 3 cups of dolomite lime, or for a 3 gallon pot, 1/4 a cup, or for a 5 gallon pot, 1/3 of a cup, or for a 7 gallon pot, 1/2 cup, or for a 10 gallon pot, 2/3 of a cup!

My last run I learned a fair bit with promix HP ......I had to hammer down on the cal mag and it likes the higher end of the ph scale not sure if that's from it becoming acidic or what but I fed too low ,for long time before I figured shit out and dialed it in.actually In flower it was loving absolutely loving 6.7 ph ffs .I don't have soil ph meter so I can't say 100 % what's the reason but that's my experience take it with a grain of salt as I have done way to many hard drugs for way to long lmao now I'm like only a little smarter then most people .....it sucks

piratebug said:

The only problem I find with PM/HP is that it initially is on the low side of the pH range, my last 3 bricks / bags averaged out to pH 6.1, and for a peat based mix that is way to low, so I always add dolomite lime to get my final mix up to pH 6.4 - 6.6. For a 2.8 cf bag, I add 3 cups of dolomite lime, or for a 3 gallon pot, 1/4 a cup, or for a 5 gallon pot, 1/3 of a cup, or for a 7 gallon pot, 1/2 cup, or for a 10 gallon pot, 2/3 of a cup!

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My first post posted just after this one .....that explains a lot lol

Ive used several times in both my veg garden and indoor,My tap water is about 7 ph and that works fine,Ive grown tomato trees in 5 g pots that needed water twice a day,I fed at approx 1EC every 3rd or so watering.I do the same with indoor.
Seams every bale can be different pH so having a meter will really help you know how to start.
Some here including me treat it the same as coco,feed low to runoff every two days deal.
Im now trying the 1 cup Gaia 444 per 5 g and water only,
I think there's many different ways it can be used successfully.

Thanks everybody.

myke said:

Ive used several times in both my veg garden and indoor,My tap water is about 7 ph and that works fine,Ive grown tomato trees in 5 g pots that needed water twice a day,I fed at approx 1EC every 3rd or so watering.I do the same with indoor.
Seams every bale can be different pH so having a meter will really help you know how to start.
Some here including me treat it the same as coco,feed low to runoff every two days deal.
Im now trying the 1 cup Gaia 444 per 5 g and water only,
I think there's many different ways it can be used successfully.

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Thanks for the input! I am considering giving the Gaia 4-4-4 amendment method a try a couple runs down the line as I've heard great things, but I'll definitely be going with a bottled or powder nutrients given during watering for this batch.
Just trying to get a sense from people whether they had better luck with a chelated hydroponic nutrient like GH Trio, or an 'organic' style nutrient meant more for a medium with active biology. I won't be using compost or anything, but HP has mycorrhizal fungi to support root development so I was thinking perhaps an input feeds the microbes as well as the plant might be beneficial. What did you feed with?

NanoGadget said:

Thanks everybody.

Thanks for the input! I am considering giving the Gaia 4-4-4 amendment method a try a couple runs down the line as I've heard great things, but I'll definitely be going with a bottled or powder nutrients given during watering for this batch.
Just trying to get a sense from people whether they had better luck with a chelated hydroponic nutrient like GH Trio, or an 'organic' style nutrient meant more for a medium with active biology. I won't be using compost or anything, but HP has mycorrhizal fungi to support root development so I was thinking perhaps an input feeds the microbes as well as the plant might be beneficial. What did you feed with?

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I fed with powdered hydro nutes. I’ve always stayed away from any dark thick shit it makes a mess. Lol.

I started off using PM. It's OK but I had pH issues. Eventually I amended with lots of perlite, a little vermiculite, 1/3 black dirt and nothing else, so I could control feeding with watering.

smokinrav said:

I started off using PM. It's OK but I had pH issues. Eventually I amended with lots of perlite, a little vermiculite, 1/3 black dirt and nothing else, so I could control feeding with watering.

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PM? My mind won't let that mean anything but powdery mildew... haha. I assume I'm just blanking on an obvious abbreviation.

NanoGadget said:

PM? My mind won't let that mean anything but powdery mildew... haha. I assume I'm just blanking on an obvious abbreviation.

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Pro Mix

smokinrav said:

I started off using PM. It's OK but I had pH issues. Eventually I amended with lots of perlite, a little vermiculite, 1/3 black dirt and nothing else, so I could control feeding with watering.

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What were the ph issues?

I’ve ran both styles, organic ( Roots organic dry amendments ) and liquid nutes ( FF Trio ) and both times, even up to now the plants did and are doing well. I only used calmag if I decided to feed with distilled water. Other than that, my organic runs needed kelp and guano because roots organic NPK Ratios are a little on the low side for flowering, always ph’d between 6.5-7. I also use flower fuel once a week to boost my ratios a bit more, and also molasses like mentioned above. On my liquid feeds I just used what the directions advised, but went a little below the feeding schedule as FF trio is a little potent. I didn’t use molasses with the liquid feed runs, didn’t feel it was necessary. As much as I like the control aspect of liquid feeding, the mixing is what I didn’t favor, which is why I primarily run organic. Most dry amendments say to use a specific amount every 3-4 weeks. I didn’t like that because it takes time for the food to break down and become available to the plant. So I top dress once a week in flower and this gives me a better idea as to how the plant is eating. I didn’t like the idea of dumping all that food in there at once, but that’s just my preference. However, before I transplant into my final pot during veg, I don’t have a choice but to dump all the amendments in the soil and mix together well, and then top dress weekly until flower arrives. So far, promix has served me well. Didn’t need to add any lime or extra perlite for drainage, right out of the bag it seemed ok. Good luck to you brotha, hope everything turns out ok.

If you're going to use pro mix.... why not use jacks 321? It's cheaper, better, and you said you wanted more control over your feedings. It doesn't get any more controllable unless you get the minerals and mix up your own base.

I make my own soil now and got use to the smell of it. When I open the bag of pro mix it sure stinks.

myke said:

I make my own soil now and got use to the smell of it. When I open the bag of pro mix it sure stinks.

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Nothing like the smell of nature!

Hollatchaboy said:

Pro Mix

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I knew I was missing the obvious!

NanoGadget said:

I knew I was missing the obvious!

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Don't worry... it took me a minute. My mind always goes to powdery mildew also.

Hollatchaboy said:

If you're going to use pro mix.... why not use jacks 321? It's cheaper, better, and you said you wanted more control over your feedings. It doesn't get any more controllable unless you get the minerals and mix up your own base.

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I went to the hydro store this afternoon. Picked up some some jacks. I am familiar and comfortable with salt based hydro so I went that direction. Also going to be using Si and calmag obviously.
What sort of ppm/ec did you run in PM HP for the different stages of growth? I typically did half recommended strength with gh trio in dwc as a starting point, but not familiar enough with this medium to feel confident. Thanks again!