There's a lot of gunk on the bottom that should be removed.
The fish has a red belly in one of he pictures and this is usually caused by something in the water.
Try doing a 75% water change and sucking the gunk off the bottom each day for a week and see if it helps.
Try adding 1-2 heaped tablespoons of rock salt for every 20 litres of water. Keep salt in there for 2 weeks and see if it helps.
The fish has a red belly in one of he pictures and this is usually caused by something in the water.
Try doing a 75% water change and sucking the gunk off the bottom each day for a week and see if it helps.
Try adding 1-2 heaped tablespoons of rock salt for every 20 litres of water. Keep salt in there for 2 weeks and see if it helps.