Volume/Ratio Calculating Al's 5-1-1 Mix
After a lot of reading I decided to use the 5-1-1 mix for my container veg. I am lucky enough to have a resource for pine bark fines relatively local, so I bought several bags that are 2 cu ft each.
I decided I needed a "big batch," so I used a bag of the pine bark fines, and then measured out 5 gal each of peat and perlite using a 1 gal bucket. The lime and CRF were also measured that way - I eyeballed about 1/4 of the 1 gal bucket for the two together.
I mixed it all up, potted my plants, and then got out a 20 gal smart pot for my blueberry plant, which is in need of repotting into something larger (I would have gone with the gritty mix, but wanted to get it in something for a year while I tracked down ingredients). I figured since I didn't need a "big batch" I would just scoop using the 1 gal bucket and do 10 scoops of the pine bark, 2 scoops each of the peat and perlite, and then add my gypsum and CRF.
As I scooped the pine bark, I realized that I was going to empty the bag - which had spilled a little, but it still had about 1.75 cu feet left in it - to make this batch. I started to wonder how that was possible - if I was using nearly the same amount of pine bark, how would I only be using 2 gal each of perlite and peat rather than nearly 5 gal each?
What did I do wrong? Is there something going on with volume and ratios and such? Did I make a mistake by scooping the pine fines? The last time I took math was calculus, and that was almost a decade ago.
I have enough of each part that I can easily do several more "big batches." I hate to waste the ingredients, but if I screwed up on the plants I already potted I'd rather just eat the loss and get it right.
To summarize, without discussing the lime/CRF -
The big batch I made has:
-1 bag stating 2 cu ft pine bark fines
-5 scooped gallons peat
-5 scooped gallons perlite
The smaller batch I made has:
-10 scooped gallons pine bark fines, which seems to be roughly 1.75 cu ft pine bark fines
-2 scooped gallons peat
-2 scooped gallons perlite
Here are the provided measures so no one has to go searching. Thank you Al for such great, detailed reading!
The 5:1:1 mix:
5 parts pine bark fines (partially composted fines are best)
1 part sphagnum peat (not reed or sedge peat please)
1-2 parts perlite
garden lime (or gypsum in some cases)
controlled release fertilizer (if preferred)
2-3 cu ft pine bark fines
5 gallons peat
5 gallons perlite
2 cups dolomitic (garden) lime (or gypsum in some cases)
2 cups CRF (if preferred)
...I'm sure this can be answered in a couple of sentences, so I apologize in advance for the long-wind post!