It was mentioned before to increase the temp and alkalinity of the tank, but that will create a more toxic environemtn if ammonia is around in the tank.
Water changes is all you will need for the time being. You will defiantley be looking at daily to twice daily changes though.
You will need to loose one of the sharks. Red tails become aggressive as they age and will fight anything that looks similar to them. And any fish that can grow to 10 inches should be removed now, even an eel. A 29 gallon tank just won't do. You will need a minimum of a 4 foot long tank for something that large.
Water changes is all you will need for the time being. You will defiantley be looking at daily to twice daily changes though.
You will need to loose one of the sharks. Red tails become aggressive as they age and will fight anything that looks similar to them. And any fish that can grow to 10 inches should be removed now, even an eel. A 29 gallon tank just won't do. You will need a minimum of a 4 foot long tank for something that large.