Went a couple more days and the 2 remaining angels and 2 dwarf gouramis are doing well, i'll wait till the weekend and if still ok i'll add some more fish.
I would dose at night and test in the morning, give or take about 12 hours, lost another angel this morning. ammonia test is clear as is nitrite, with nitrate around 40ppm.
Unfortunately i've lost one of my angelfish, all tests ive done are fine so i'm at a bit of a loss as to what caused its death. it seemed a very shy fish so i don't know if it was being bullied.
Ammonia dropped to zero and i've topped up again, nitrites showing a more purple shade of pink now and when i tested for nitrates they showed at 80ppm. All seems to be going well.
Im using the API master test kit which shows purple at 5ppm for nitrites, tested again today and the pink isn't so shocking now lol. ammonia test is between 2 and 3 ppm.