LCD has strange characters when not lcd.clear() is sent

Does anybody know what i can do about this?

Without seeing your code we would only be guessing.

I have send the software code for photoduino to the Arduino one v3, and there it is the same, but i cannot put everywhere in the code this lcd.clear() command.

I think you may be using Google translate or something similar. Try rephrasing this and run it through the translator again.

Don