Hello BYAP,
I'm still in the process of finishing building my larger system, but in the meantime, I've assembled a mini grow bed to test things in. It started yesterday so it is still in its initial stage, I guess.
This is what it looks like:


It has a cabbage, a tomato and garlic in it.
I had to adjust the LECA level this morning, moved the garlic, and after 8 hours of being in there, the little bugger is already growing roots.

aaanyway... sorry for rambling, I've borrowed some Ferropol
(pic here:
http://i.minus.com/i5c4vXo9RBigK.jpg)
from a cousin, which he uses for his aquarium plants and I'm certain it won't harm the future fish I'll bring into the system. I've added 15ml on the first day for initial nutrients.
I'm trying to find some seaweed extract but so far no luck. I've posted on a few social networks that I was looking for natural liquid fertilizers, specially seaweed extract. Someone just gave me a bottle of something called "Substral - Plant Food".
Is this stuff safe? Will it harm fishes?
The composition on the label reads:
Fertilizer NPK: 6-3-6
N: 6% (nitrogen)
P2O5: 3% (Phosphorus oxide?)
K2O: 6% (Potassium)
Fe: 0,03% (Tony Stark)
Oligoelements: Copper, Manganese(?), Molybdenum and Zinc.
This all translated from Portuguese, so pardon any incoherence.
Any ideas?
Cheers.