Thank you so much for that comprehensive advice. I'm concerned about the salt with the cories because I've read that that can affect them. There are also live plants in the tank. I only did two doses of the formaldehyde because that's what the dosage said, but I think I'll do a big water change...
Here's a picture of them in the dark with the phone flash. It's so hard to see if they've got a gold sheen on their bodies. If they do it's not obvious and it's only around their gills, and that might just be their own colouring, I just don't know.
I'll keep trying to get a video of their...
Hi there,
I've got a 55L tank Ammonia 0ppm, Nitrite 0ppm, nitrate 5ppm with 6 male guppies (now 5) and 6 pygmy cories.
I added one guppy and the 6 cories around 3 weeks ago. The guppy was thin when I got it but I just thought it was a different body shape.
After a while I saw he was...