Outdoor Hydro? How much water?

I have a question for the more experienced. Consider an outdoor grow with a 20 gal tub inside of a 35 gal trash can. The tub can contain hydroton and the bottom of the trash can can hold 15 gal of nutes. Solar pump set up with possibly a wick back up system.

My main question is this as I live in So Cal and it is hot, -- how fast will the nutes be consumed/evaporated. I can cover the top of the tub with shading or even cut a hole in the top of a trash can lid to help minimize evaporation. I can even rig a remote resevoir. However, I need to know how fast the nutes will be consumed to replace them. I am trying to design a system that will require minimal visits/maintainance.

Thank in advance.

the res needs to stay at aorund 70 or so. If you want a low maintenance grow go for soil

Thanks for the reply.

The containers could be buried to the rim in soil. That should help keep them cool.

Soil might work instead of hydroton. Wicks could be installed as a back up with an external resevoir solar pumping water on a timer.

However, I still need to know how much water will be lost and how fast it will need to be replaced. Temperatures here are often over 100. I am thinking about a steep hillside grow. Getting water there is an issue.

Stop. Think. Do soil.

Well, lets say I use soil. Maybe even soil with water crystals. What is my anticipated water consumption during the 100 plus degree summer months?

Actually, one of the reasons I was considering hydro is that the water would be in a self contained system. Less water to haul . . .

you will have to change the res out weekly so you would actually have to use more water and have to check on the hydro system daily to make sure your pH doesn't drift too much.

I though 15 gals in the resevoir would delay changes for more than one week.

OK. Lets say its a soil grow with a wicked container. Will the water in the resevoir need to be changed? Aren't there toxins in the soil from the plant that need to be flushed?

buddy, just grow in the ground, no wick system or anything like that...

Thanks for the input on this one.

Digging a hole in the dirt is an option. If a container is used, the hole just has to be a little deeper. However, the site I am thinking of is steep. Digging holes is a pain. Hauling water is a pain. I use ropes and crampons to climb the hill. Security has its price.

I just thought that water in a container with wicks is a great way to make the water stretch.