Illness/Sickness: Floating Salamander Larvae

For the past few days, I have noticed my salamander larvae (most likely Ambystoma maculatum) are floating to the surface of the water. They can force their selves to swim back down, but they just float right back up. Now they are trying to get stuck in algae when they swim back down so they can stay down. They also try to swim down and under a rock so they don't float back up. The larvae are both about an inch long. What is this illness/sickness called? How can I treat it? Can the illness/sickness result in death?

Thanks

How much do you feed them? How warm is your tank?

Sorry for not replying until now, I was at a party.

There is daphnia in the tank and I also feed them other food every day or two. The tank's temperature is variable. I generally keep it in the cool basement during the day and the upstairs sun room at night. I estimate that when the tank is in the basement, the temperature may be around 50-60 degrees Fahrenheit. When the tank is in the sun room at night, the temperature depends on how hot it was outside and if we had the curtains open the previous day. I guess the temperature might also depend on how cold it gets overnight. I estimate that the temperature could be anywhere around 50-80 degrees, rarely being 80.

However, this routine changes somewhat and I might have the tank upstairs in the sun room during the day for different amounts of time, for example, and it might be in the basement at night such as last night when I was not at my house.

The floating has seemed to stop all but a little bit, but a few days ago, the floating had to be affecting several factors of their life because the floating was constant.

The problem might be caused by the temperature fluctuation. Warm water is able to dissolve less gas, so when water warms up, gasses dissipate (possibly depositing within the tissues of the animals' bodies). Also, larvae sometimes ingest bubbles in other ways and this makes them float. Underfeeding is one possible cause, but probably not the only one. Why not keep them in the basement all the time? I think the constant 50-60F should be fine.