A quick post on my soil mix ratios. So Ive been working on this mix for 7 grows now and making slight ratio changes. The one im using now is number 7 and is 10% more castings than my last mix. I did this because I wanted to reduce my pot size from 40 ltr to 25 and wanted to stick to a every other day watering regime. Im happy with this one now it allows me to water every second day without the first of the water running straight through the pot but the pots are nice and light. If I leave them 3 days the first bit of water i give them runs out and that means my soil has become slightly hydrophobic. If the the soil is let become hydrophobic continually the problem can compound causing dry spots through the mix.
Im going to call this my my second cycle soil, even though technically its kinda been through more cycles. Your soil fertility should improve over each cycle. 4th-5th cycle is when it really should come into its own and be producing best results. I dunno about that but makes a lot of sense to me.
Note: I would use 10% extra coco for seedlings in future. 10% less vermicast.
So the ratios are:
50% coco
10% perlite
20% compost
20% vermicast
If you have to buy compost id recommend mushroom compost, the vermi cast could be replaced with manure if you need to.
I also add iron sulphate @ 100gr/100ltr
Dolomite @ 2 cups/100ltr
epsom salt @ 2 cups/100ltr
Gypsum @ 2 cups/100ltr
ground crusher dust @ 2 cups/100ltr (note that volcanic rock dust or any other fancy name is the exact same thing as crusher dust without the fancy name or price tag, this costs nothing really)
Blood and bone @ 2 cups/100ltr, the one i use is cheap and nothing fancy it contains, composted manure, blood & bone, fish meal, seaweed.
The other things i add i dont measure and can be used if you have them on hand or even for top dressing your soil. If you have ash or ground seashell throw some in as well. I throw a few handfuls of sand for each 25ltr as well for its silicon and slow release calcium content. There is no real science to how much of anything to add really but steady steady feed those microbes. Top dressing your soil is key in organics. When i make my microbe teas I top dress with the waste. I leave any leaf trim in the pots, i top dress with sulphur,iron, dolomite at least once through the grow. It takes microbes and enzymes time to break things down into a plant usable form of nutrients so just be adding steady steady. the main thing really is research what you add so you get diversity. I see people tripling and quadrupling of some elements and totally missing others.
The best way to mix your soil if your doing 100ltr is on a concrete slab with a shovel. I did have pics of the process but i lost them. I did however steal em back from one of my threads in another place, but thye tiny and cant be up sized. But here is a link to my gallery if ya wanna check em out. app.php/gallery/album/54
I add bits of Styrofoam in the bottom couple of inches of my pot, just break up any old Styrofoam you can get into about 1 inch or less pieces. This does two things, firstly it acts as aeration at the bottom of the pot where the mix tends to hold water. Secondly it acts as an air root pruner, same principal as an air pot. Roots hit the air , are pruned and there fore multiply in other places, just like pruning the top of a plant.
Once the soil is in the pots, I add a sprinkle of Great White Shark microbes, and water in with molasses @ 1 tbsp/ 4 ltr. and aloe if you have it.
Now let it cook in a nice warm dark place, the longer the better. If longer than a month give it another dose of molasses or a microbe tea.
Im sure i left something out but hope this helps.
Here is a pic of a Dutch Delight week 5 of flower in the same mix.