two things im planting in root soil(low nute soil) in 7x7x8 cm pots for the first week because i heard that if u place the seeds in compost the roots due to their sensitivity cant handle any nutes and can slow down growth quite alot!! i was told this by a canadian lowryder breeder.
Your caution is well placed but i think lil over cautious bro.
I guess that all depends on which compost he's using..some are HOT as hell and will fry a plant real easy..
I used to use seedling compost, but after trialling Autos with different brands, now just use regular MP compost.. Wests Multi-purpose with added john innes is pretty decent and not too hot and a good choice for the non-organic folks..
Oganic compost that is available in bags will work fine too, just check its contents NPK, if its ericaceous or non-ericaceous and ph etc... the bags info should give you all you need..
If in doubt plant in layers.. Ie plant in good/ample sized pot (Autos like to dive deep) fill the bottom 3/4s of the pot with the organic compost of choice, and fill the upper 1/4 with low nute seedling compost. that way as it grows it'll slowly grow into the hotter soil.
How do i do it? Firstly i sow seeds straight into 2 or 3L pots, using either purchased organic soil, or my own compost if its plentiful...
I dont layer the compost or add seedling type soil , as i've never experienced seedlings getting fried with the compost i use, BUT that doesnt mean that it doesnt happen...So keep a watchful eye.
Feed only water until showing preflowers, then slowly introduce Bio Bloom + molasses til Flush/harvest..
They VERY rarely out grow the pots, which is good as i grow my Autos in a smallish cab powered by 1 x 150w + 70w HPS
Run on 18/6 from start to finish...
As much as hot soil will stunt growth which is BAAAD in these strains, you may also find that transplanting at such an immature age will also shock and stunt the growth unless youre super careful.
With this in mind, that is why i remove the need to pot-up by sowing into the pots theyll finish in.
If youre using large wattage lighting you should prolly go for a min of 1 gal pots, as they will def out grow the pots.
then i was thinking of transplanting into compost!! secondly how do i make guano tea?? .
wouldnt it be easier if i just used liquid guano in the water when watering?? im not using any chemicals i want everything 100% organic!!