This tank has been running for about 3 months but it was set up using all of the existing water from the old tank and the same filter
The filter got a light rinsing with tank water, straight rain water basically.
We did a big change last night, approx 200 litres. Luckily it rained so we dont yet have town supply water in our tanks.
We havent had to use town water yet. We have 2 large water tanks for the house, one is concrete and the other is plastic.
Thanks for everyones help. The parrot has some of his colour back this morning but is still hanging around at the surface. The confusing thing is that everybody else is just fine.
We're not sure what has thrown the ammonia and nitrates/nitrites sky high between the last water change as we havent done anything different.
If he is no better tonight we will put him in a bucket and treat with salt I think. There doesnt appear to be anything externally wrong with him. Hes not bloated, definitley no white spot present, hes just doing a lot of gulping at the surface