I have a 10 gal. tank that now contains 3 neon tetras, 1 placostamis, 2 fan-tailed gold fish and a floating nusrery with 6 guppy fry. I had the water tested three days ago and it showed a slightly high nitrate reading so I purchased 2 live plants to help correct this. Now my goldfish have taken to staying on the bottom of the tank and I'm not sure if they are sick or if something else is wrong. Any help would be appreciated. Thanks!