Arduino Mega PWM - 100ms Period - SSR and Heater I'm not very advanced in Arduino "core" functions, so I need your help.

I'm using a Solid State Relay in order to control a heating element, with a PID Library (PID_v1.h) to obtain the OUTPUT of the PWM.

The code itself is not a problem, so that I'll not post it here. 

Summarizing, this is the code where I send the PWM to the Relay:
    analogWrite(RELAY_OUT, outputValue);

I've found in this article that:
"The analogWrite function is used to set the duty cycle of a PWM pulse train that operates at approximately 500 Hz. Thus, with a frequency = 500 Hz, the period is = 2 ms."

My concern is that the response time of the relay (FOTEK SSR-60 DA) is 10ms (to turn on or to turn off), but I DO NOT KNOW how to configure Arduino PWM to work accordingly to this Relay, in a period greater than 10ms.

I've found in some pages some people changing the clock frequency in order to have a "fast pwm", but I need to know what values I have to use to get a "slow pwm", for a period greater then 10ms.

Can you help me with that? I've been searching a lot for this answer, but I could not find any "definitive"answer.

Thank you in advance!

Everton
I'd suggest using the TimerOne library. 

Call Timer1.initialize(10000) in setup. 
Then call Timer1.pwm(pin, duty); in your loop. Where pin is 11, 12, or 13 for the MEGA, and duty is between 0 and 1023.