How much does your grow media cost per square foot of grow space?

Growroom Design
#1

For example I’ve been using rockwool and I have:

  • 8 square feet of grow space
  • My grow media costs me 25$ per grow

25/8 = $3.12 per square foot

Curious what the average cost is?

EDIT
So I haven’t had to buy my media in a while, but I just checked again and with shipping costs how they are now my cost actually works out in the range of $3.75 - $5 / ft² depending on which type of rockwool I’m using. I think I can do it with rockwool granules for about $2.50 / ft² but I have to purchase enough for 3 crops at once.

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#2

After buying my initial bags of soil and compost a couple of years ago, no costs anymore.

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#3

An interesting metric… :thinking:

My current grow works out to $4.87 CDN per square foot as it was all fresh.
As that’s organic soil, nutriments are included.

Cheers
G

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#4

An interesting metric to think about for sure @Gpaw
I have used my soil for multiple runs and lightly Amend each time, the longer I use it the cheaper my cost gets.

If your using rockwool or hydroton I think you should add in your fertilizer cost as well

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#5

Hmm… well I spend $100 each cycle to test my beds. I add maybe another $10 in ammendments, but they are long paid for. That’s for 24 square feet of grow space.

$110/24 ft² = $4.58 / ft²

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#6

It’s going to be hard to beat the cost of Hydroton (or similar). The initial cost is reasonable, but the residual costs can bring it down to nearly a zero cost over the life of it…

I can buy (2) 50L bags for $50US and fill a 120 sq ft. grow room with up to 50 net pot lids filled with it, and still have some left over. I can then wash and reuse that Hydroton forever without ever spending another penny on my media. No amendments - no nothing. Just wash and go.

I stopped growing for a bit in 2015 and got rid of all my Hydroton, but I had been using it for almost 10 years at that time and it was still going strong. Needless to say, when I started growing again, I bought a bunch of Hydroton!

$50/120 ft² = $.42 / ft² the first time you use it, and it’s free after that.

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#7

A bale of Promix is $40 bucks. I get two runs out of in in 8 sq ft so…$2.50?

2 and a half runs really. But sometimes I run different pot sizes so these numbers are highly variable.

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#8

Yes, why are we not talking cubic feet, out of curiosity?

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#9

How you use promix you have to mix it with something or straight out of the bag

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#10

Not really… Zero cost that is… You gotta compare apples to apples…

You’re using ferts / nutes in that hydroton, that would be in a soil mix by default. Its really not a straight comparison unless you average it out a little.

I would compare the cost of say 3-5 grows with the same media, avg the cost of media plus nutrients.

You’ll use more nutes in 5 grows in hydroton or rockwool, than I would in soil. And I recycle the hell outta my soil, so I use other nutes to recharge it before reusing it. Its not really a linear comparison, because hydroton is inert otherwise and even crappy soil would provide some kind of nutrition for a little while.

So, the higher initial cost of soil is not factoring in the initial nutes that are in it.

Soil can be reused forever as well, if you care for it. No Till obviously is one way, but you can use soil like hydroton as well, only difference is I am recharging while re-composting for the next usage while you just add the nutes to the reservoir after cleaning the hydroton off.

That being said, I’ve bought bagged soil, bulk perlite, bulk compost / mushroom soil and generally make my own mix in the end. It would be a hell of a job figuring out my cost per sq ft / cu ft with the varying volumes (a yard of compost, 4cu ft of perlite, etc). Then broken down into what I use for my mix. Not up for that math this early. LOL

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#11

Straight out of the bag. I used to add some perlite but it’s unnecessary.

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#12

No idea because the therapeutic benefits I get from both the process and results are: priceless.

:hugs:

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#14

You’re missing my point…

I buy a bag of topsoil. You buy a bag of hydroton. We buy NOTHING else. no ferts at all, just straight water. Your plants don’t have a chance.

Its not a competition, its pointing out that more goes into figuring out that average than just the purchase of the medium. There are costs to using inert mediums other than the medium itself. Soil can be seed to finish possibly with no other costs (might not be the best, but plant could go thru an entire life cycle in a bag of soil)

And if I was being totally neutral, I need to average in the cost of my compost, even though it may be kitchen scraps, there’s some inherent cost in it. Ultimately I’d like to be 100% compost and not needing any purchased nutes…

So. not saying one is better than the other, just pointing out you need to figure in all factors when comparing. To each his own, I’ve seen phenominal buds grown every way imaginable, certainly more than one way to skin this cat :smiley:

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#16

If we’re going to use a different metric I use ~$15 worth of nutes per grow. So $17.50 for a 2x4

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#17

So just to clarify a little:

This is just one metric, and it’s only a small part of the overall story of what an entire cycle will cost, but the reason I asked this question specifically is I honestly wasn’t sure if my cost per square foot was extreme.

I haven’t seen anyone using coco post yet, but I’d definitely be interested in seeing cost of similar mediums (in this case rockwool vs coco). I imagine brick coco will be cheaper, but bag coco will probably
have a similar cost to rockwool (per sq ft) or even be a little more expensive.

For hydro/rockwool/coco fert cost is definitely a major factor in overall expenses.

BUT Ferts can be hard to calculate, at least for me, because I buy them so rarely now I honestly have no idea the rate at which I’ll need to buy more, and different grows I have used different amounts of ferts, but the amount of grow media can be the same each time.

Thanks everyone so far for posting, I definitely am less worried about my media cost as it seems to be within a fairly normal range.

Still would like to see some coco users chime in if they see this :grimacing:

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#18

$30-$40/1.5cuft bag of roots original(Amazon) so too much lol ends up being like $15/5gal pot

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#19

I think shipping is probably a large part of why that is so expensive.

I can’t find anything like that locally either so I also end up ordering my stuff online.

I checked https://growershouse.com/ because I find their prices are usually a lot better than amazon and that’s where I get most my grow stuff here in the states.

Sadly after shipping costs the roots organic is about the same price as amazon.

#20

EDIT:

So I haven’t had to buy my media in a while, but I just checked again and with shipping costs how they are now my cost actually works out in the range of $3.75 - $5 depending on which type of rockwool I’m using.

I think next time I will try these, as I THINK I can get away with $2.50 per sq foot, but it will take 3 grows to use them all:

image

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#21

About $1.75/sq. ft. I generally start seeds and clones in rockwool cubes and plant into finer perlite. Finer grades of perlite are cheaper and hold more water than coarse. I’m always looking for opened bags on discount at the hydro store. I like a little vermiculite or coco if using coarser perlite. I need to start buying from feed stores. Supposed to be way cheaper. Under $1/sq ft would be terrific lol.

Less if you factor in the recovery of about 1/3rd of the media post-harvest. Whatever easily shakes off the rootball. Probably closer to $1.25 sq. ft then.

But I also waste media on culled seedplants and males so I’ll call it at $1.75/sq ft.

If rockwool mini cubes were cheap, I’d use those. My favorite media.

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#22

lol for me to run my 4x8 flood table i use about 3 bags of canna coco 35 each bag and a huge bag of perlite for about 25 bucks. and use it for 2 runs so about 75 bucks a run.

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