Forum Discussion
DutchmenSport
Jul 28, 2014Explorer
Don't know what kind of camper you have, but let's assume your black and gray water Y into the same outlet. If they do, here's a trick that REALLY works.
First you need to purchase a 3rd valve, like a flush-king

Camping world sells them, as does any RV dealership.
What you are going to do is back-flush the gray water into the black tank.
Step 1. Attach flush king and open the valve.
Step 2. Open the valve of the black tank and let everything drain until it stops.
Step 3. Close the flush king.
Step 4. Open the Gray valve and let the water back-flush into the black tank for about 5 seconds then shut the gray valve again.
Step 5. Open the flush king valve and the black valve and you'll be amazed how much MORE will come out of the black.
Step 6. Repeat steps 2 thru 5 two more times! Each time will pull more and more out.
Step 7. Once done, close the black and open the gray and open the flush king, and let the gray finish draining, cleaning out your hoses.
This simple process will pull a LOT of stuff from the black tank. You'll be amazed.
The secret is to get a flush king valve, or something similar, with a clear section where you can see what's coming out.
About TP... any brand that works for you! The secret is the amount of water to flush it out of your black tank!
First you need to purchase a 3rd valve, like a flush-king

Camping world sells them, as does any RV dealership.
What you are going to do is back-flush the gray water into the black tank.
Step 1. Attach flush king and open the valve.
Step 2. Open the valve of the black tank and let everything drain until it stops.
Step 3. Close the flush king.
Step 4. Open the Gray valve and let the water back-flush into the black tank for about 5 seconds then shut the gray valve again.
Step 5. Open the flush king valve and the black valve and you'll be amazed how much MORE will come out of the black.
Step 6. Repeat steps 2 thru 5 two more times! Each time will pull more and more out.
Step 7. Once done, close the black and open the gray and open the flush king, and let the gray finish draining, cleaning out your hoses.
This simple process will pull a LOT of stuff from the black tank. You'll be amazed.
The secret is to get a flush king valve, or something similar, with a clear section where you can see what's coming out.
About TP... any brand that works for you! The secret is the amount of water to flush it out of your black tank!
About Travel Trailer Group
44,052 PostsLatest Activity: Oct 29, 2025