how can i do to keep my photos in the icloud when i delete all my pics of my iphone?

If you have iCloud Photo Library turned on, any photos you delete from the phone will also be deleted from iCloud and from any other devices connected to that iCloud Photo Library. The most you can do to reduce the storage space required on the phone is to turn on Settings > iCloud > Photos > Optimize iPhone Storage.

Apple does not currently offer any cloud-only storage settings. You can suggest that more options be offered via http://www.apple.com/feedback/icloud.html

There are 3rd party cloud services which have cloud-only options.

Clau29 wrote:

thank you x the info. And wich one is the reason to buy more MB in the icloud if when you delete your pictures in the phone they will be deleted automatically in the cloud. So, you will never have more space in the cloud then the space do you have in your phone or in any apple device?? 😕

No, you can use more space in iCloud than you are using in any one Apple device. As I stated in my first reply, with regard to iCloud Photo Library you can turn on Settings > iCloud > Photos > Optimize iPhone Storage. That will allow smaller optimized copies of photos to be kept on the phone if space is needed while full size originals are stored on iCloud.

There are other things that also might require more iCloud storage such as if you are backing up multiple iPhones/iPads to iCloud or if you are manually uploading items (from a computer that does not have iCloud Drive turned on) to iCloud Drive at https://www.icloud.com/

Clau29 wrote:

I BOUGHT LAST WEEK 50 MB IN ICLOUD!! 😐

If you decide that you don't need the additional storage, the following has instructions on how to downgrade: iCloud storage upgrades and downgrades - Apple Support

but you have to turn icloud photo library on to turn on optimized iphone storage. and you said that any photo deleted from the iphone will then delete from the icloud if the photo library is turned on. So how do you turn on optimize iphone storage and turn off photo library??????>?> Maybe my iphone 5s has different options. if i go to settings>icloud>photo> I must also turn on icloud photo library.......... if i dont turn on icloud photo library the optimize iphone storage will not show up. Help

dmussat wrote:

but you have to turn icloud photo library on to turn on optimized iphone storage. and you said that any photo deleted from the iphone will then delete from the icloud if the photo library is turned on. So how do you turn on optimize iphone storage and turn off photo library??????>?> Maybe my iphone 5s has different options. if i go to settings>icloud>photo> I must also turn on icloud photo library.......... if i dont turn on icloud photo library the optimize iphone storage will not show up. Help

You cannot. Optimize Storage is a method to potentially reduce the space on your phone required for the photos in iCloud Photo Library. It is only applicable when you are using iCloud Photo Library. The design of iCloud Photo Library is that all of your photos will be BOTH on iCloud and on your iPhone (and any other devices where you have iCloud Photo Library on. The Optimize Storage option only affects the size of the photos stored on the device.