Holding tank monitor help?!?

[captainkf]

So my plan to build holding tanks is coming along. I am bit hung up on holding tank monitors. I am unsure of what brands and styles are best. Do the sensors attach to the inside or outside of the tanks? Can anyone help?

What are the thoughts on fiberglass fresh water tanks? Would this be safe? Flavour the water?

I have seen a number of "professional" conversions that use a combined black/grey water tank. Any thoughts?

-Richard

[Eric von Kleist]

I have only a gray water tank on my bus. It is constructed from a piece of 8" PVC pipe 10' long, and it holds 25 gallons. I have a 40 gallon water tank. I just keep an eye on the water tank, and I drain the gray water tank when the water tank is about half empty. My tank is vented: the top of the pipe cap at the high end of the tank has a 3/8" hole drilled in it. If I forget to check the fresh water level, sometimes I see water dripping from the vent on the gray water tank, which reminds me to dump it.

[captainkf]

So, I was able to pick up 3 tanks (used) with sensors and a monitor for $60. Each tank holds about 60 gallons. I am think these should work just fine. However the dimensions of the tanks change where I was going to place a few things. Oh well.

-Richard