Choosing wiring schematic for arduino powered outlet.

I'm trying to build an areoponics garden and I couldn't find a commercial timer that I could program to run on an interval of 15mins on, 5min pause, 24/7. So I bought an arduino uno, a 5v 8 channel relay srd-05vdc-sl-c, two 15amp outlets, a 3-pronged power cord, and 14gauge straided wire. I am using all this to power a 16w/120v submersible water pump.

I wanted to know whether if its possible to provide enough power through the uno board and relay, or if I need to wire the powercord to the outlet and create a circuit between the cord, relay, and outlet.

16watt at 120 vac should be manageable with the relay board.

But are you using this where proper certification for insurance is required?

When it comes to water you should have a GFI in the circuit.

There are power switch tails available.
One example:

Show us a good schematic of your circuit.

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For safety you could also consider a 12V DC pump. Makes switching with the Arduino easier as well. This way you can keep all line voltages away from the water.

@larryd - Thats cool! That must be a new one, I'm only familiar with the single outlet version, which has been discontinued. Unfortunately this model is on back order.

@op - this is the way to go, along with a GFCI breaker.

I know that I should have bought a GFI, but I already went over my budget building my greenhouse that I tried to cut any corner that I could. I tried to attach the photos in my original post, but it keeps sending me to a page with the "413 request entry is too large". and I don't know how to lower the file size or resolution.

"Safety" is a bad corner to cut. There are several options that are much cheaper than a casket.

$10 will buy you this: http://www.homedepot.com/p/Tower-Manufacturing-Corporation-3-Wire-GFCI-Outlet-Adapter-30439005/202510242?cm_mmc=Shopping|THD|G|0|G-VF-PLA-D27E-Electrical|&gclid=EAIaIQobChMIt-eRl5CO1QIVVTuBCh1YcQLwEAQYAyABEgJRPPD_BwE&gclsrc=aw.ds

Whenever I’ve built anything controlling 230v AC mains power I’ve included opto-isolators. Many solid state relays contain built-in opto-isolation including the appropriate pull-up/pull-down resistors so they can be driven directly from an Arduino pin. If using solid state relays ensure you include a conventional circuit breaker so the gadget may be completely isolated from the hot stuff.