Hello Sue,

. Thank you for that! The fish haven’t poop’d as much as they would do normally but I held off feeding them since Sunday and only fed them a small amount yesterday. I haven’t caught them doing anything yet! I noticed on Monday, one of the blue platy girls had a very fine, almost hair thickness, thread of poo, with a couple of bubbles along the line and could have been possibly more translucent than white? Prior to this recent upset, all of the fish would have more or less beige or pinkish colour, and definitely thicker, trailing anything from .5cm, to occasionally a long 2cm piece, before breaking off. When I first got the blue platys, I couldn’t help noticing how white (normal thickness) their poo was for the first few days. Again, I just put this down to their food at the fish store, and it soon became beige or pinkish once they were eating algae and Tetramin coloured flakes here.
I decided to do another smaller WC yesterday, after all, as some of the other fish were still flashing (no white spots yet and will have to test for the golden shimmer – that’s tricky with the calico sunsets). Most of the fish do seem to be a little better on the flashing today but still doing some. The boy balloons are the friskiest I’ve ever seen in these last few days – coincidence? I think it explains when I saw a couple of them displaying a lowered top fin (I panicked thinking they were going the same way as the sick calico), but maybe this is a stress from each other? The two girl blue platys seem to be a bit tetchy with each other too - in competition perhaps? My sick platy seems to have benefitted from the WCs – she’s still doing her vacant floating thing, from time to time, or settling on the bottom quite still, but she gets up even if I come into the room (never mind near to the tank), so definitely more energetic, but it's still worrying watching her go from active to catatonic and back again. Do you think there is something parasitic going on?
If a salt treatment won't harm them, what sort of reaction should I expect if I put some in the next WC? Will they get more stressed? Should I follow a specific regime, i.e. temperature, how much, how often, WCs in between, etc.? I've read a few things but not entirely clear about it as some people disagree with each other over this. Is it also worth trying peas on the next feed, before a salt treatment, to help clear things out a bit, generally? How much pea per fish is the right amount? As always, thanks so much for sharing your knowledge