Water pump on solar and grid

I have a Talapia fish pond that currently runs on the power grid, I want to run it off of solar during the day and grid power at night or when there isn't enough sun. But it has to be automatically switching since the pump can never be shut off. How would a system like that be wired? I was thinking a amp switch between panel and charge controller. Amps from panel drops below a certian point it switchs off the panel and allows grid power to pass to the pump. Has anyone rigged up such a system? Thanks
Comments
You DONT switch it.
You simply install a grid tie solar system and reduce your household bill. And buy a backup generator if the fish need air. If grid fails, it's often from a storm, which may prevent PV from working, and you need a generator anyway.
|| Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
|| VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A
solar: http://tinyurl.com/LMR-Solar
gen: http://tinyurl.com/LMR-Lister ,
The Kisae Transfer switch was made for this purpose. Mostly used by boat people that have both dock and solar power. I've used it and it's a good product.