Pro mix vs. Potting soil.

Hey everyone, few questions that I would appreciate if some of you could give your answer/opinion on.


I have used Subcool's super soil (exact recipe) and followed his whole system pretty much to the T. It worked great, I ran it with some timewreck I got from a good, clean mother plant of a friend, that isnt being chopped to hell by a million people. First grow ever, good quality genetics and followed the whole subcool reg. - turned out great and was really pretty easy going. (I really like how the super soil made with roots organics holds water really well so you can not worry about watering every day)

Now while it turned out good, I did have some minor issue with gnats and gnat larvae and some type of crawling bugs that were very small, pretty much fit the description of a root aphid, but in the midst of all my root aphid research I came across hypoaspis miles and pretty much got lost. I still do not know if I had root aphids or if they were mites, or if they were even a beneficial mite like the hypoaspis miles.

Bottom line, this scares me as I have heard and continue to hear that Roots Organics comes with bugs... and it seems the main complaint is the gnats/root aphids, many cases sounding very similar to mine.

SO.... My question is,

What would you prefer to use as your "base soil" ?

Promix or a bag soil like Roots Organics?

Subcool says that mixing with promix is his last choice. He says it "runs out of gas" which does make sense because the promix is unfertilized, while roots organics has a lot of the amendments already in it that you will be adding more of.

So would you naturally just increase the amounts of amendments if you were to go with pro-mix?

I like the thought of the pro mix being more of a "from scratch" soil, and im pretty sure cheaper than $11/ 1.5 cf of Roots Organics + the cost of amendments.

I have been eyeing LumperDawgz soil recipe or something close to it...


Thoughts?

Promix shrinks as it dries, I did not like it one bit in fabric pots. it seemed I was always left with a gap between the side of the bags and the promix once it dried. I also find it doesn't hold water well at all. I will be making a new mix this year with half promix and half something else I haven't decided what yet though

sunshine #4 works for me.its like promix only with alot of coco instead of peatmoss so it drains better.

Thanks you guys. I like the sound of sunshine 4. I think the coco in root organics is a big reason it holds water so well.

Can anybody confirm that adding more of the same amendments that subcools recipe calls for to promix would make a soil that doesnt "run out of gas". Seems to me the only diff between pro mix and roots organics is amendments. Id prefer a water only soil

BACG said:

Can anybody confirm that adding more of the same amendments that subcools recipe calls for to promix would make a soil that doesnt "run out of gas". Seems to me the only diff between pro mix and roots organics is amendments. Id prefer a water only soil

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You could go with the same recipe and then top dress some amendments and worm castings a few weeks in to flower ..... or like you said you could just add a bit more when you make the soil. I run multiple strains so I like to make my soil a little scaled back as some of the sativas don't require as much juice, and then top I dress the ones that I know will need it at some point in flower.

Thank you for the input st0w!

If you're going to use SAM#4 as a base you'll want to add extra castings or compost to it, and possibly up the other amendments. SAM#4 is strictly soil-less as is, it has both sphagnum and coco coir, virtually no nutrients though.

Nullis said:

If you're going to use SAM#4 as a base you'll want to add extra castings or compost to it, and possibly up the other amendments. SAM#4 is strictly soil-less as is, it has both sphagnum and coco coir, virtually no nutrients though.

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Thank you, this helps me a lot. I think I have the right idea I just want to clarify with some of you folks with more experience.

I have a friend that has been in the game for 20 yrs and he didnt really like the idea of super soil indoors, but told me to try it out. He likes a light airy soil like plain or lightly amended pro mix, he likes it for the control and speed, he says he can control a toxicity or deficiency much quicker than soil, which makes sense to me.

He tried to mix some of subcools super soil and used a bale of pro mix . He said his plants showed deficiencies the whole time and his yield went down. This makes sense to me because like you said pro mix is unfertilized. I didnt seem to have any yellowing or any other def's till about week 5 or 6 using roots organics as a base, which actually seemed just about right to me.

all I gotta say is ROOTS has killed four of my very established ladies before, I transplanted them and they dropped dead within 20 hours, and had ZERO issues using roots for about two years prior to that, but I did start to notice more weeds, and that means its outside and possibly exposed to herbicides, which is my theory on what happened. Killed them deader than hell, and it was almost instantly, they drooped like they hadn't been watered in weeks and died soon thereafter. I know it was the roots because only the plants that used the mix died, I had some ocean forest leftover and those plants did ok, needless to say, I haven't used roots, since.
I can't recommend Vermifire enough, it's the best soil I've ever used and it's not terribly expensive

If you go with the sunshine #4 you will definatly need to top dress throughout your cycle.Roots Organic sells a nutrient kit called the master pack for about 50 bucks that comes with a little of each of their products(about enough for 6 pants for one grow)and it comes with a really good feed schedule that includes instructions for top dress,feed schedule,and even foliar for what product to use when.If you try it you wan to go with the 5ml master feed schedule as the bok has several different schedules in it.The only thing I stray on is I only go 3/4 strength at most usually only 1/2 strength unless plants show deficiencies.

Which pro mix product are you referring to? I've used Pro MIX HP for some time and haven't had any problems with it. It has a good amount of perlite and drains well (the HP stands for high porosity) which is great for me as I tend to be a little heavy handed with my watering.

And yes to adding amendments but it doesn't need as much because the myco helps with root uptake.

st0wandgrow said:

You could go with the same recipe and then top dress some amendments and worm castings a few weeks in to flower ..... or like you said you could just add a bit more when you make the soil. I run multiple strains so I like to make my soil a little scaled back as some of the sativas don't require as much juice, and then top I dress the ones that I know will need it at some point in flower.

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Can you expand a bit ?
My local hardware store has promix BX with mycorrhizae and I'm thinking of giving it a go.
I usually run Sub's recipe with sunshine but limited resources in my little town made me look at switching up my base soil.

I like running a pretty warm soil (Medium to heavy Indica strains, 1200 watt) - any guesses on additive increase/decrease when using the BX ?

GreatwhiteNorth said:

Can you expand a bit ?
My local hardware store has promix BX with mycorrhizae and I'm thinking of giving it a go.
I usually run Sub's recipe with sunshine but limited resources in my little town made me look at switching up my base soil.

I like running a pretty warm soil (Medium to heavy Indica strains, 1200 watt) - any guesses on additive increase/decrease when using the BX ?

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In all honesty I've never used pro mix, and I've never made super soil. I looked up the ingredients for the pro mix, and it's a pretty basic medium. Depending on the price, you may be better off just buying a bale of peat at Home Depot and inoculating the root zone yourself with mycorrhizal fungi.

Obviously you would need to add castings/compost, and some aeration bits to round out the base. I'm assuming this is pretty standard across the organic soil spectrum.

I suppose the amendments would be where the various recipes part ways. Myself, I aim for 3 cups of various meals per cubic foot, and an equal amount of rock dusts per cf. Diversity is good, but I don't think you have to have a dozen different ingredients. IMO kelp meal, neem seed cake, crab shell meal, and alfalfa meal are the mainstays. I also like to use some type of all purpose fert like Espoma Garden Tone just to round it out. Some sort of liming agent beyond that would be advisable with a peat base. I use oyster shell meal, and have used gypsum, calcium carbonate (home depot), and dolomite lime.

That gives me a soil that is pretty well received by all strains. I usually top dress most plants around week 3-4 of flower after a 6 week veg... but some sativas don't need anything beyond the original dirt. When I top dress I combine 50/50 my own castings and soil from the same batch that the plants are already in. 6 cups of that mix per plant in 7 gallon buckets. That mix will have added to it roughly a half cup per plant (strain dependent) of the same amendments that the soil was first made with, sans the rock dusts and liming agents.

Pretty much a water only deal beyond that, with the occasional compost and seed tea, and an application or two of silica and fish hydrolysate along the way.

That was pretty windy, but Im baked and get chatty and the wife is laying beside me snoring.

mudhead31 said:

sunshine #4 works for me.its like promix only with alot of coco instead of peatmoss so it drains better.

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Sunshine #4 has 0% coco. It is peat.
Just so no one gets confused. The reason it drains better is that it contains more perlite.

Sent from Northern Colorado.

thanks for that merlin I guess the guy that owns my local hydro shop misinformed me as he said it was like 60% coco I apologize for any confusion I may have caused with my misinformation.

Mr.Head said:

Promix shrinks as it dries, I did not like it one bit in fabric pots. it seemed I was always left with a gap between the side of the bags and the promix once it dried. I also find it doesn't hold water well at all. I will be making a new mix this year with half promix and half something else I haven't decided what yet though

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Same problem i had

Husseinps said:

Same problem i had

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Is that gap a problem???It does the same thing when I use it but isn't it good for the plant if the roots can breath freely? Isn't that the point of smart pots?

mudhead31 said:

Is that gap a problem???It does the same thing when I use it but isn't it good for the plant if the roots can breath freely? Isn't that the point of smart pots?

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Not really a problem but then ur seedling will need special attention/ extra effort. Just unnecessary.

air pots are meant to breathe and dry out a little faster, but with that gap I was drying out at least a day before I would be if the bag was filled properly. The roots are supposed to grow through the bag and proon themselves, when this gap was there it wasn't happening properly.

Not really a problem, but when I'm growing organically watering certain strains that frequently can lead to overfeeding.

I'm back to plastic pots anyways, I didn't see any advantage to running root pouches. They leak water out the sides while watering and are not good for indoor growers that are worried about their hard wood floors I had them in trays 2-3 inches wider the pouches and still got water everywhere, on top of that after a single use they have a white scuzz on the outside I can't get off, they are in the trash.

If I use Airpots again it will be the plastic brand, not bags. If I was going to do an outside potted garden root pouches would be my first choice, I would have much better results outside guaranteed. They are cheap and disposable IMO.