Decrease the frequency of the loop() loop

Why not use millis() for timing?

unsgined long delayOneK=1000;
unsigned long timePast = millis();

voided setup()
{
if ( (millis() - timePast) >= delayOneK )
{
this will execute one a second
timePast=millis();
}

}

Look at File|Examples|02.Digital|BlinkWithoutDelay to use millis() for timing instead of delay().