X2 on the bulging tank. My tank has a overflow hose attached about 80% up on the side wall of the tank. The hose turns up and then makes a loop downward and pokes through the compartment floor. When the water reaches the outlet fitting (80%full), water does not come out the overflow. But when the water bulges the tank and reaches the top of the overflow loop, siphoning starts and the water continues to drain until it goes below the drain fitting. I was startled once when filling my tank and not paying too much attention; I saw water coming out the overflow. So I shut the water off and then why water kept pouring out the overflow. I then investigated and saw where the top 20 gallons siphoned out - LOL!!!
Another problem is that the hose fitting to the pump is about 20% up on the sidewall. This is a very poor design. It means that you need to carry that bottom water around all the time and not be able to use it. This means that because of the design, 167 lbs. of unusable water is being carried.
A more vertical tank with a bottom outlet would be a better design, such as in my previous class-C.
Gale & Hank- 2012 Berkshire 390BH