Clair de Lune Pedalling

[fryderyk_franciszek_chopin]

Hi, I'm currently learning Clair de lune by Debussy right now, at the beginning of the piece it says con sordino, should I use the una corda or the one in the middle? I'm using an upright piano btw so the middle is a muffler pedal instead of sostenuto

Thanks

[lelle]

Con sordino refers to una corda here as far as I know.

the middle pedal which holds notes for you on grand pianos is called the sostenuto pedal.

The middle pedal which muffles the sound for evening practice is as far as I know never indicated in the classical repertoire

[fryderyk_franciszek_chopin]

Con sordino refers to una corda here as far as I know.

the middle pedal which holds notes for you on grand pianos is called the sostenuto pedal.

The middle pedal which muffles the sound for evening practice is as far as I know never indicated in the classical repertoire

Alright, thanks!

[fryderyk_franciszek_chopin]

Btw one more question, should I hold the Una corda for the entire piece, or is there any specific parts that doesn't need it?

[yqxpiano]

This is more of a subjective thing. Up to interpretation. But I do have some advice.
First, don’t use una corda JUST because a part is soft in a piece.
Second, don’t be so confident in your dynamic abilities that it becomes a virtue to not use it. 
Use it when it feels right. Heck, you don’t need to use it at all. Or you could use it a whole lot. Experiment and see if you like it.
Your left foot should be on the una corda the whole time, even if you never use in a piece. Many people use their left foot for support by putting it on the floor, but if sitting correctly you will have all the support you need. Moving your foot off the una corda pedal for support on strong chords should be an exception, not a rule. 
Una corda does not just make things sound quieter. It creates a whole different color in the sound. This is partly due to the fact that where the felt hammers strike the strings will be more compact, and the una corda area less.
Finally, the una corda, damper, and sostenuto pedals are NOT a on/off switch. They are a dimmer switch with infinite possibilities. Too many people forget this last part. 

[lelle]

Good point! It's reasonable to interpret the con sordino as "you should use the soft pedal in this piece" and not "the soft pedal must be heldag down at all times"