Extended capacity of Gray/Black holding tanks

[Us3Here]

Since we are nearly "full" with our gray and black holding tanks, I did a test to see how much more I can put in them, once the tank reads 100%,

Our next two stops will be at state parks with electricity and water only, so this information is important to us, and maybe for others here.

Our coach is level, ensured with a 4 foot level, and added water via the manual toilet until 100% read on the SeeLevel II. I added a gallon at a time and checked the Tecma electric toilet light color too. After 2 additional gallons, the yellow light turned to red, to prevent us to use the electric toilet, unless I do a manual override.

I was able to add an additional 7 gallons of water to the manual toilet until I started seeing water with a flashlight, and consider it then to be unusable, or maxed out.

The same with the gray water, I added a total of 14.5 gallons to the shower until it stopped draining.

So, when I read 100% full, my toilet can take 9 additional gallons of fluid and the shower/gray water 14.5 gallons

[Mr_D]

On our DSDP the monitor panel is adjustable using a jewelers screwdriver. None of them are really accurate, even ours, which uses the external sensor pads.

[lp5151]

Us3Here: "Our coach is level, ensured with a 4 foot level, and added water via the manual toilet until 100% read on the SeeLevel II. I added a gallon at a time and checked the Tecma electric toilet light color too. After 2 additional gallons, the yellow light turned to red, to prevent us to use the electric toilet, unless I do a manual override."

how do you do the manual override? Isn't there a danger of overfilling or overusing the electric toilet when it's showing red light?