DIY Sump check valve to stop sump pump

I setup a DIY sump for my tank. I want to make sure I don't flood the house. The setup of the drain ensures that it will only drain what the sump tank can handle. My question is if the drain for some reason fails and the pump continues to pump the sump until its dry the main tank will overflow. I want to put a float check that turns off the power to my pump if the level reaches to high. How can I do this? The float checks just have wiring and Im confused on how to get my idea to work. Thanks for the help!

Really if you setup a herbie style overflow and call it a day, thats failsafe enough, its a proven design. If you want to go the electronic route..need to find somebody smarter than me :P

Ryan has it. You should have the water level in the sump low enough that in the event of power failure you don't flood the sump by backflushing and the drains from the tank sufficiently large that it can accommodate the initial high flow upon power on.

That's the easiest way to develop a DIY sump, I can't help with the float checks etc.

That was my initial thought too. I setup the intake of the drain to be fairly high so that the water level isn't noticeable when viewing the tank. But this leaves the sump fairly low on water. I mean I guess that doesn't matter as long as the pump doesn't go dry I suppose?

I think I can help on both counts. First, do you only have one drain going to the sump? Best situation is at least two, a main and a safety in case the main becomes clogged. If your tank is drilled with an overflow “reef ready” style you can use the return hole for your safety and just run your return over the top. This is how my display is plumbed. Also to minimize the amount of drain back a small hole should be drilled about an 1/8” below water level on your return fitting which will break the siphon.
As far as setting up the failsafe for the return pump it can be done a couple ways, one would be to use a controller like an Apex which would use a level sensor to shut down the pump, but they are pricey. The other would require som DIY wiring of a level sensor and a relay to shut off the pump.
But honestly having two drains, one at normal running level and the other set 1/2” below the top trim would make for a very reliable system. If you have questions please feel free to message me. Here are the drains in my overflow. The main has a valve below the tank to control the water level in the overflow. The smaller safety is a direct pipe to the sump.Attachment 122941