tank sensors, Can the new electonic sensors be installed on older models

I see that the new Winnies have electronic senors on outside of the tanks.  It is so hard to clean the interior sensors. Since I got my coach they read 1/3 full and they are empty.  Plan to add a cleaning solution from camping world and back flushing to see if I can loosen some of the debre.  Does any one have anyother suggestions and can these electronic senors be added????     

Can't help with the external sensors but cleaning the interior is half a tank of water (fairly hot if possible) Dawn and Clorox and drive around corners left and right for an hour or so.

When we need to do a good cleaning of our holding tanks we use Calgon Water Softener (found in the laundry detergent aisle at the grocery store).  We use the liquid form and pour about a capful into the holding tank that is filled with water.  Let it sit for a little while and then drain.  We then rinse with clear water when we are done.  Some folks add just a few drops of detergent as well when doing the cleaning with this method but we have never used the detergent.  We have been using this for 10 years and it works great.  It is much cheaper then buying the RV products and it is safe.  No harsh chemicals or bleach.
Found this method on many RV forums years ago and it works wonders. 

Sue

Like Sue, I also read about the Calgon and deturgent method.  What I have been doing all these years is to add a capfull of Calgon liquid to the black and grey tanks after dumping.  The deturgent is added a few drops each time we fill the toilet bowl.  This helps keep stuff from sticking in the bowl as well as having a similar accumulative effect in the black tank.  The grey tank gets its share of soap from dish washing.

At the end of each Summer tour I use a pressure wand down the toilet.  There always is some residue inspite of careful backflushing at each dump. 

It has made no difference to me  between the current interior tank sensors or the exterior capacitive sensors that my ''06 Winnebago had.  There will be times when the indicators in the coach do not read correctly due to stuff on the walls of the tank.  In that case a couple bags of ice cubes sloshing in the tank will sometimes knock it free.  If not, the pressure wand. A commercial cleaner I tried early on gave underwhelming results that is why I looked for other possibilities.

Our new PC came with built in tank sprayers for both tanks. We haven't checked them out yet but it looks like you hook a hose up to the inlet located near the macerator controls then turn them on and they spray inside the tanks. Is this a new addition or is it on the older PC's? If it is on the older ones, does it help and how often do you use them to hose down the inside of your tanks?

The macerator instructions also tell us to dump the black then close the valve; Open the grey, let the water flow into the black and equalize the tanks; close the grey and dump the black again. Open the grey, let the water equalize; close the grey and dump the black yet again; finally, you dump the grey and it rinses your hose. It says this gets the soapy water from the grey into the black to coat the tank. It takes a while this way but John and I thought it was so cool the first time we dumped. Sure beats the stinky slinky that wouldn't hook up right on the rental rig.   

John and Holly,

    We had the sprayer on both the 2008 model and now on the 2012 model.  My DH loves this feature.  He uses it everytime he dumbs the black tank and just about once a week on the gray tank.  He defintely uses it prior to coming home from a trip.  If we have a full hookup he leaves the gray tank open and the black closed.  Once the black fills up or we are ready to leave he dumps it and then uses the sprayer to clean it out. 

Sue 

Let me clarify a bit.  I use the backflush provided by the macerator setup everytime possible. It is not high pressure. I even have a 10 ft. section of collapsable hose to use when a dump station does not have a water hook-up. Never-the-less, I still use the high pressure wand at the end of trips or if needed.

As for the dump sequence you describe, ok if you cannot use the backflush capability.  Otherwise just dump/flush via macerator until the effluent is clear.