It's also tiresome trying to figure out what you mean. For example,
you don't say whether the output of the electrolytic is supposed to
supply the operating current for the LED or whether you're only using
it for timing. Then you say that the LED stays on with 1V on the cap,
but that it starts to dim when the voltage on the cap is between 1 and
1.5V, which doesn't seem to make much sense. Since you're the one
asking questions it seems to me that you're the one who should be
putting forth the effort to at least make yourself understood for the
convenience of those whom you are asking for help.