How long will this last?

I want to turn on and off an aquarium pump running on 120v AC from a relay controlled by Arduino. They only use about 6w maximum. However, I'm not sure how long an SSR will last me if I turn it on and off say, every 10 seconds 24/7. How long will it last me? What is a good relay to use.

I have very little (= almost none) experience with aquaria, but I thought the pump stayed on all the time? It's the heater that goes off and on....

For SSR it doesn't matter if you switching it's 1 time per year or 100 times per second, as long as start current in the normal operational range. I can't say the same about pump... Mechanic is more sensitive for such things

Magician: For SSR it doesn't matter if you switching it's 1 time per year or 100 times per second, as long as start current in the normal operational range. I can't say the same about pump... Mechanic is more sensitive for such things

Your point is correct, The SCRs/Triac device(s) are/is actually switching at it's maximum switching speed when the input is at a continuous on-state as the device(s) turn on and back off every zero crossing. SSRs/Triacs can only fire as fast as the line frequency, so 50/60 Hz is the theoretical maximum switching speed.

Lefty