OK...So there's no such thing as a dumb question. Right?

My idiot lights on the black tank were not working correctly. So without knowing the actual level, I went ahead and flushed the black tank. Then, I connected the rinse hose and flushed multiple times for about thirty minutes (filling and flushing). Things are back into working order.

Now the question...

In the event the idiot lights were NOT working, will there be a way to "gauge" the level of the tank without having the unthinkable happen? Its been a looonnnggg time since "the good ole days". How did we do this before the invention of idiot lights? :huh:

You'll know when it's getting near full because it will start to burp when flushed, because the vent pipe is under water.

I wouldn't stress too much about the level sensors, I'm on my 4th 5er & have NEVER had any of the sensors for black/gray that worked past 30 days, Ive tried all cleaners & cleaning methods & it's just not worth the expense, time, aggravation for the sensors to read once. As stated you'll learn the sound of the black getting full, I typically drain the black once a week unless I notice the sound change. I leave the bath gray open when hooked up to sewer til a couple days before draining black as the shower & wash machine drain into it, the galley black is only kitchen sink & dishwasher so it usually lasts til draining black.

We haven't been able to get our tank readings normal for some time now.

Mostly, we keep the galley and bathroom tanks open when we are parked. For the black tank, we empty it mostly once a week (for two people, and that is subjective also on how "full of it" each of us is, LOL!!) :blink: . If there's any doubt, you will hear and see a bubble come up when you flush. Then you know it's time to dump the black tank.

Same for us, I don't even bother to look at the sensor lights any more.

You know when the black tank is almost full by the noise when flushing. I dump about every 7 days. The gray tanks sometimes fill in less than a week, so I dump a little water out and empty them when dumping the black tank.

I will also listen for the BURP when flushing.. My sensors are working ,but still listen.

My lights have not worked since new. Because I move so often, I leave the grey closed and always dump the black before moving, flushing with the grey. The only exception is an overnight stay, I don't dump but will dump the next day. I try to travel with grey and black nearly empty and about 1/3 on fresh water.

My lights have not worked since new. Because I move so often, I leave the grey closed and always dump the black before moving, flushing with the grey. The only exception is an overnight stay, I don't dump but will dump the next day. I try to travel with grey and black nearly empty and about 1/3 on fresh water.

Thanks Titan Guy. That's the perfect plan for travels. Right now we are stationary prepping to hunker down for the winter. This will be interesting...

I too never was able to get a clear indication of tank levels.

I finally got frustrated enough to install the Tech-Edge iSeries tank monitor system. It works with conductive copper tape on the outside of the tank so even if the inside starts to get dirty they still work.

The one kicker is they are temperature sensitive so I calibrated one grey tank at about 60F degrees and one at 80F degrees and depending on the current ambient temperature I can lean more towards one reading vs. the other. Generally they are around a 5-10% swing between grey tanks.

I calibrated the black and fresh at 70F and that has worked well so far.