I agree, and it's crucial to compost with that much manure.
If you can get seaweed you can probably get some crab shells, may take some time, and it's a chore to pulverize them unless you have a burly coffee grinder, You
need aeration that part is very important.
The nettles you can either make a good tea out of or you can compost that with your manure, it also works well as a topdress later in growth.
For probably less than a hundred dollars you could get a good setup of minerals, amendments and a thing of promix hp (not ideal but ok for budget grows)
if you are re-using the soil i'd add some bio-char too, it's cheap and it works as an aeration also.
Get some minerals too, again for re-using soil I think it's a good idea to get minerals and amendments that breakdown at different rates, like greensand for example.
If money wasn't an issue, i'd go with volcanic rock over perlite for aeration. Neem meal is a must, so is crab meal or at least oyster meal, good source of worm castings (homemade is best)
I recently had to make a new batch of soil i'll be using over and over (my landlord tossed a bunch of my soil
) Anyways this is what I put in my mix, and you can change SO much of this, it's just what I like
aeration I use bio-char, pumice, oyster shell and volcanic rock
Greensand, rock phosphates, basalt, azomite, and oyster meal for my minerals
Neem meal, crab meal, insect meal (haven't tried yet, see thread regarding insect frass), kelp meal.
For teas I use comfrey and dandelion (works INSANE), standard AACT.
In the past I have used (and with good results) rabbit and alpaca manures, bat guano, seabird guano, etc
One thing you don't have which is the cornerstone for a successful organic grow is a source of humus/microbes/fungi etc.
That's were either a good EWC source or a good leaf compost comes in.
