Hi, our common goldy (Mr Gold - you gotta love 6yo orignality!) has suddenly developed a big squarish lump on the left side of his stomach. Most of the time he's his usual self, and he definitely enthusiastic about food (and begging for more) but sometimes he seems to be drifting. He's also starting to hold his tail round in a bit of an angle as though his tummy is pushing it to the side. To start with I thought it was constipation or overeating as I noticed the lump the day after I gave them frozen bloodworms (they normally have tetra bloodworms in jelly) and they had been pretty enthusiastic about them. I've given them extra veggies and they've been eating them with relish, even the peas which they normally don't care for, but it's still unchanged. I've noticed some poop which has the rope like consistency I associate with stoppered up goldies, but this morning he was trailing white mucus, which I didn't like the look of one little bit. Water params are ammonia 0 (max 0.5 after filter crash 3 weeks ago....lots of water changes and prime) nitrite 0 and nitrate 15-40 (daily outpt of about 30ppm) a bit high I know, but I've ordered lots of plants for their tank which should be here this week. Diet is based on tetra gold japan mini pellets (extra roughage to prevent constipation in fancy goldfish) and supplemented with a variety of veggies (peas but not hugely keen, broccoli - they LOVE it, sweetcorn very popular, garlic) bloodworms, daphnia. I'm very very careful about not overfeeding too. certainly when I gravel vac thoroughly each week there is very little food that comes up. So, does anyone have any ideas what's up with Mr Gold and what I can do with it?