Review on 💧 Valterra T21301VP Horst Miracle Probe - Black Water Tanks, Pack of 4: Optimal Cleaning Solution for Waste Management by Mark Vazquez

We bought our camper used and the Black Water gauge kept showing 2/3 or FULL even right after draining. I tried the Camco Flex unit with hose and pipe, but the black water tank is about 70 inches wide and only about 12 inches high, so not very efficient. I finally found Horst sensors, watched videos, read reviews and simply installed them. Before installing, I drove to our nearby scrap yard, put 4 inch 2x6 boards on the opposite side of the RV to give it a "slope" for better drainage, and watched it drain completely. Back home I started installing the probes, noting the 'notch' on the side of the terminal to indicate which side the top cap was on. Removing the old probes was fairly easy after I loosened the 3/8" nuts and gently pulled them out with needle nose pliers. Upon closer inspection, it turned out that the old probes were quite sad and short. One at a time, I put the new Horst gauge in place, put a loop of wire on the copper rod and holding the slot with a pair of thin vises, slowly tighten the 3/8" nut on the tank, until it's tight. Be careful not to overtighten. See the picture to determine how deep they need to be tightened. Best I guess from 1/4" to 3/8". Once that was done I tightened the wire nut holding the slot in place. With a push of the Black water button, finally the message "Empty" appeared. I smeared waterproof silicone sealant onto the ends of the connectors and nuts to keep water out (see image). Total time for all was less than 1 hour.