Don't want to buy an expensive float valve?
Make your own!
I have been building a hydroponics garden, and I wanted to make sure my reservoir doesn't run dry and destroy my pump (or kill my plants), but a side entry float valve would have cost me $30+ at the local hardware store, and I had already spent my budget on pipes and plants.
So, calling on my childhood obsession over MacGyver, I looked for what I had lying around, and built a cheap and surprisingly effective float valve! (effectively for free!)
Step 1: Disassemble
If you look at the spray end, you should notice it looks like an inverse nut.
Push your pliers into the corners, and turn like a screw, it isn't hard to get undone.
When you have the front off, unscrew the small plastic nut from the other end, and slide out the innards.