Teardrops n Tiny Travel Trailers

Greetings friends,

I am in the midst (year 2 ) of designing and building my very own teardrop trailer. I am ordering the little water tank on Monday. This is a small tank, only 11 gallons installed right above the axel and under the bed. I am looking for a solution for a decent water level gauge. I can't use a simple closed tube because the the tank location. I could a tube on the side inside the compartment (see picture) but I would have to lift the bed and open the lid to see it. I need something electrical that comes in from the side. I also want to keep the cost down. The tank is from Plastic-Mart and is a model: R-RVB319. It will have the fittings installed where I choose. I have figured out my fill, vent and drain locations and wondering if I will need others for a gauge. It's not a huge issue and not a critical item, however, if I can find an easy solution I would consider it. Thanks all!



Also, since I am posting on the subject, here is my basic plumbing schematic.