How many minutes refilling the buckets in ebb and flow?

Hello fellas!
I want to try my first time ever Hydroponic in outdoor. A DIY ebb and flow.

I am trying with the water pump, and need 10 min to refill the 5 buckets. Its a 4W water pump.

The system needs around 7 minuts to drain. So this is around 17 minutes. It´s a lot ? The system will be placed in outdoors, under the sun. Very hot, all days over 91F /31ºC
Tomorrow over 104F / 40ºC

I have another question. How many times at day, must refill the buckets?

Thank you all in advance and sorry about my english!
Have a good day!

If you can place the reservoir in the ground it might help keep the temp down. You might need to insulate the ground around the outside of the reservoir to keep the ground from heating up.. If it's buried in ground covered with grass, watering the grass would help keep the ground temps down.. Other than a chilled and insulated reservoir there's not much else you can do.. Even blowing air on an above ground reservoir wont remove enough heat to cool it..

How ever many it takes to grow weed. Your system is different than what anybody has done as far as I know. Seems like you gotta do your own trial and error. I do a flood drain. I dont "fill" the buckets. My buckets are filled with clay pebbles. I just turn the pump on and and let them get wet. I vary how much and how long during the grow cycle. Less at the start more later. You want the roots to get wet, but not stay soaking all day. They need to dry out a lil.

Why not just top feed the plants using 1/8 inch tubing that goes inside a grommet that gets attached to a 1/2" PVC. If you can grow massive tomato plants that way marijuana would be a piece of cake. Watering this way in 90 degree temps full sun would be water pump on for 40 seconds off for 20-30 minutes. When in shade or during sun down on for 40 seconds off 50 minutes - 1 hour.