I'm in Australia and have a new Class C, its only taken a little while for the gray tank sensors to foul up. The dealer did a tank clean for me and I had to pay. I've now bought some drop-in RV tank cleaning tablets and have yet see see if they work at all. However, in the meantime I've been thinking about lower cost ideas that might work as well or better. The first is perhaps to disolve dishwasher tablets and flush them into the holding tank and drive around with the tank fairly full to loosen stuff up. The other is to make up a solution of bicarbonate of soda and try that.What do forum members think about these ideas?

water and soap and drive and soak (for days) then drive then dumpORif its going to set a while unused, there is a septic tank additivethat will eat everything clean, but takes a month or so to do the jobfill with water put in the septic cleaner, drive to stirthen let it set and digest the wasteget a power rinser to use while dumping to keep the sensors clean

If you have it, Dawn dish soap followed by lots of water and some water softener like Calgon. Again US products, so they might not be available, but you sure should have something similar.

If you use your rig a lot you will get used to knowing how full they are without the sensors. Also by monitoring the sensors on your fresh water tank. They don't foul. The black and grey do frequently. My personal opinion is its not worth effort. If you equalize your black and grey tanks and they can hold all the water from the fresh tank then there is no issue to begin with. JMHO

They all do it. Don’t worry about it.

I drop a Dish-washing pod into each tank, before we leave on a trip. Add about 5 gallons of Hot water and by the time we arrive it's usually clean.

Gray Tank Cleaning | Good Sam Community

MrWizard
Moderator
Jul 13, 2018
water and soap and drive and soak (for days) then drive then dump
OR
if its going to set a while unused, there is a septic tank additive
that will eat everything clean, but takes a month or so to do the job
fill with water put in the septic cleaner, drive to stir
then let it set and digest the waste

get a power rinser to use while dumping to keep the sensors clean
donn0128
Explorer II
Jul 13, 2018
If you have it, Dawn dish soap followed by lots of water and some water softener like Calgon. Again US products, so they might not be available, but you sure should have something similar.
dave17352
Explorer
Jul 13, 2018
If you use your rig a lot you will get used to knowing how full they are without the sensors. Also by monitoring the sensors on your fresh water tank. They don't foul. The black and grey do frequently. My personal opinion is its not worth effort. If you equalize your black and grey tanks and they can hold all the water from the fresh tank then there is no issue to begin with. JMHO
Mandalay_Parr
Explorer
Jul 13, 2018
They all do it. Don’t worry about it.
3_dog_nights
Explorer
Jul 13, 2018
I drop a Dish-washing pod into each tank, before we leave on a trip. Add about 5 gallons of Hot water and by the time we arrive it's usually clean.
cfuller3
Explorer
Jul 13, 2018
Yeah, get used to that quality. You're going to see a lot of it.
SoundGuy
Explorer
Jul 14, 2018
Downunda wrote:
I'm in Australia and have a new Class C, its only taken a little while for the gray tank sensors to foul up.

Even when you're careful about what you allow to drain into the grey tank it still results in an amazing amount of sludge that will foul the tank sensors. For several years now I've been using Walex Elemonate in my grey tank and am amazed at the amount of stuff that comes out with the water. Here's an Australian source for Elemonate.
Downunda
Explorer
Jul 14, 2018
Thanks, Elomonate is what I have and will try it in the next few days, however at $18 a packet here I don't see it as a long term solution.

Thanks folks for the other suggestions as well, I wll work my way through them.
Regards
JimK-NY
Explorer II
Jul 14, 2018
I cannot imagine what is going into your gray tank that is causing issues. Our gray water is from the shower and from washing dishes. Washing dishes can add some debris to the tank. We use a stainless steel filter to trap most of the solids before they can reach the tank. I do add a little bleach every so often to help keep the tank clean and to avoid any odors.
doxiemom11
Explorer II
Jul 14, 2018
We don't do anything specific to clean our grey tank. Why? It's filled with soapy water from showers and doing dishes all the time. You will get so you know when it's getting full , same with the black. Sensors not needed.