Hello everyone,
I’ve been gifted an entire unopened bail of promix HP by a friend. I’ve never used this stuff before, but from what ive been able to gather, its a completely inert media with little to no nutritional value for plants. I guess it almost could be considered a hydroponic medium. My next grow im wanting to do in hempy style pots and was just curious if this stuff would work for that style of grow or if id be better of using straight perlite. Pro’s, Con’s?? Thanks for the help.
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You’re treading in some murky water here. I see people running octopots and have wondered if it was somewhat doable with a system like that…bottomfeed with a tall soil mass and maybe add some airstone? The soil/soilless may compact too much and might run into anaerobic battles in the lower mix. @Papalag @ifish …hmmm others I wanted to tag arent around anymore…I’m gonna make sure my bookmarks are still available…too much info to lose.
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Thanks, ive already decided against it.
It works just fine as a hempy mix, just make sure the bottom layer over the hole is something like perlite or clay pebbles or lava rock.
It’s just peat-perlite instead of coco-perlite, only difference is they add some extra lime to adjust the low-pH of the pro-mix. Good enough for nurseries, good enough to grow weed.
Pure perlite will hold a bit less water, but functionally your experience will be very similar. You can add extra perlite to the pro-mix HP, meet somewhere in the middle.
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Hi @Tappy I do use pro mix bx although friends us the pro mix HP the bx retains water more they say but sofar I see no difference ,they both have perlite in it and mycorrhizae and yes totally inert
I normally add 20 % more perlite but 2 friends use it straight up no extra perlite so I figured I’d give it a try
It works well in my Octopots and I do use it with my moms
I was mixing 50/50 pro mix and happy frog but I like the totally inert mix better
Hope this helped
Good luck @douggyfresh420
Paps
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Well, what the hell, i now have a gigantic bail of this stuff sitting in my garage. Might as well make use of it lol
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Didnt even think of using hydroton or something as a drainage tool!!!
Many thanks @vernal
I have used soil…this may help flushing soil again for future use!!!
I think this is my 7th round with this soil.
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ProMix HP has more perlite than the BX. Otherwise they are the same. I add more perlite to the BX than the HP, but I do add more perlite to both blends. BTW, HP stands for High Porosity.
ProMix is my preferred soil-less medium, I have been using it for a long time, I use the BX straight for all of my veggies, flowers and herbs.
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I use Promix HP for my mix. I use this for about half my mix. I add more perlite just like @Calyxander. Promix is great because it has inert media (SPM “peat”) and aeration (perlite), but it also has lime for PH balance.
Peat also blows most other medias out of the water as far as CEC (Cation Exchange Capacity). This is the amount of nutrients the soil is able to hold. The pantry of the plant.
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Do any of you guys mix coco with your ProMix? Reasons why? And why not?
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For coco, I’m using the hydro range of 5.7 thru 6.2ish.
When using the Promix, what is the PH range?
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I use sunshine #4…maxibloom (lucas formula) with silica in constantly reused soil and the new Harvest Miracle by Micro Labs from @AquaTerra !
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Can I use straight leca balls (I think it’s just hydrotron) in a hempy solo? I cant find a bag of perlite anywhere in town and dont feel like burning 40 bucks in fuel (plus long weekend traffic/cops) for an 8$ bag of perlite lol
And can I start the seedlings in a solo shot cup with soil. Obviously using minimal soil
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I don’t know the construction of your houses chimney stacks where you live , but here we fill our space between brick chimney and our flues in perlite , our builders merchants stock it , @Grease_Monkey
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Theres typically perlite around, canadian tire lists 1 left.but it doesnt exist lol. And my typical bad timing my seeds are popped and ready. I may take a sifter to my gfs garden lol lots of perlite in there
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Hey bud, I wouldn’t try to do pure hydroton in a hempy. Unless maybe you were doing some sort of recirculating system. It really holds next to no water and doesn’t wick well, I think you’d need to water it like every few hours. Perlite actually holds quite a bit of water and seems to wick ok.
This is just my .02, but I did try a pure hydroton hempy as one of my first grows ever and it went poorly lol… It was like my second or third grow though so take with a grain of salt. I did do quite a few pure perlite hempies and they went ok.
Good luck 
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That’s enough of a reason for me. I’ll just sprout in a tiny cup and find perlite asap
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There are different grades on perlite the stuff I sell says horticultural grade. Not sure if there is a difference between that and stuff used in construction.
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I shoot for 6.5 but anywhere near there should do fine.
As I understand it the promix is very acidic. When I let my pots dry out too much they get burnt.
All the best
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I think perlite is just perlite : )
Think horticultural grade has just been sieved nto different grades/ sizes and construction perlite is just standard size , both still need rinsed befor use in gardening , just pay more for horticultural grade as you can get it in larger chunks if wanted and gardeners are willing to pay more than builders : )
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