Cheers.
I underdosed on the salt and the bichir still freaked out a bit after 20-30min of dosing. It was swimming erratically so I did a 20% WC and he is now resting.
Tank isn't fully cycled at the moment because the seller want the bichir gone so I had to put him in the tank after only 4 weeks and 2 days. There are 9 congo tetras, a butterfly fish and a peter's elephantnose that I was using to cycle (I added them progressively over the 4 weeks).
Ammonia is ~0.05-0.13ppm. I've been testing twice a day (morning and night) and doing WC where necessary (roughly 30% every 2-3 days), as well as triple dosing seachem prime and a bit of seachem stability.