(See Bottom of Page for what we use in our blackwater tank.)
I don't think anyone really enjoys dumping the holding tanks. I want to make the process as painless as possible. The factory design with the pull-out blue 3" hose on my Roadtrek is a nice idea. If the sewer opening is positioned close enough, and there are no curbs or rises between the Roadtrek and sewer, this arrangement works rather well and is fairly quick. The trouble is, the sewer hose is positioned quite low to the ground and I often find there is some sort of obstacle between my sewer hose and the sewer drain, usually a curb. Unfortunately, waste won't flow uphill, so I am often not able to dump with my factory setup.
I originally solved this problem with the Sewer Solution ( see Sewer Solution article ), which is a clever water-powered macerator that works well. The disadvantage with the Sewer Solution is that it requires a water hose to provide the power. This is an extra step and not always convenient, depending on the dump station.
In my continued quest for a better dumping solution, I purchased a FloJet portable waste pump (macerator model 18555) from Camping World. This was designed as a portable kit that included a case, macerator pump with connectors for waste hoses, and on⁄off hand switch with plug connector for 12 volt power. Please note that macerators now come standard on Roadtreks.
UPDATE 4/22/2020: Our FloJet macerator stopped working in Fall 2018, so I replaced it with a much less expensive (about $70) macerator that I found on Amazon. The one I purchased was an "Amarine Made 12V Self-Priming RV Mount Macerator Waste Water Pump 45 LPM 12 GPM Boat RV Marine". I wasn't expecting much for the price, but it was very simple to switch over my hose and hand switch to the new macerator. The new macerator works great, just as well as my $250 original one, plus it is significantly less noisy. So far it's still going strong. What a pleasant surprise.
The green 1 inch discharge hose shown in this picture did not come with the macerator. It was part of my Sewer Solution and consists of two 10 foot segments connected together. Any 1 inch diameter hose will work. For that matter, a 3⁄4 inch garden hose would also work for shorter distances (less than 25 feet). The macerator comes with a pre-attached fitting for a garden hose. The clear plastic piece attached to the 3 inch macerator inlet also did not come with it. I added this since I found it is handy to be able to see what is flowing into the macerator. This allows you to see when the tanks are flowing clear water as well as to make sure the hose is empty before disconnecting.
This is the macerator all hooked up. I pushed the blue sewer hose back into the holder so there is a continuous downhill angle into the pump. You can see the black flex tubing covering my 12 volt supply wires. I ran these to the 12 volt distribution panel inside the electrical cabinet. The supply is fused. There are several feet of wire I keep coiled inside the storage compartment. It will easily pull out so I can plug it into the macerator plug. The red button on the hand switch turns the pump on and off. Also seen on the pump is a side port to which you can connect a water hose to rinse out the sewer hose if you want. This comes with a shut off valve and anti-backflow device. I've never used the side port. I prefer to just run clean water into the blackwater and graywater tanks to clean out the blue sewer hose and green discharge hose.
The sewer cap seen here is what I use on the other end of the green hose. It plugs right in using a friction fitting (as seen here with a 1 inch diameter PVC pipe). This sewer cap came with my Sewer Solution, but you could make one up with standard plumbing parts.
I store the macerator pump in the side compartment. I permanently clamped the green discharge hose onto the pump. Once less step to worry about.
Here is a fuller view of my side storage compartment. I took some Rubbermaid storage bins and cut them down with a saber saw to a height that would fit. I also cut out part of the front to allow easy access. These work well. Sewer items are in the left bin, fresh water items in the center bin, and electrical items on the right side, including a surge protector as discussed here .
Impressions and My Dumping Technique:
Overall this macerator works very well. I particularly like this arrangement as it allows me to use the standard blue sewer hose to dump in a conventional manner if the dump station conditions allow. When I need to use the macerator due to distance or elevation of the sewer opening, it only takes a minute or two to hook it up. I first open the blackwater tank valve. This takes about one minute to pump out. I will then close the valve and run several bowls of water through the toilet. I re-open the blackwater valve and pump out the remaining flush water with the macerator. Then I close the blackwater valve and open the graywater valve. I turn the macerator back on and a minute or so later the gray water is all pumped out. I will then run some clean water down the sink to flush out the graywater tank, sewer hose, and green discharge hose. The macerator will pump almost all the residual water out of the sewer hose. When I disconnect the macerator from the blue sewer hose, I will lift it to let the green discharge hose drain completely into the dump station sewer. I then coil the green discharge hose up, disconnect the 12 volt plug, and store the macerator and its attached discharge hose in the side compartment. I also have a cap that seals off the far end of the green discharge hose. The blue sewer hose goes back to it's storage position and I'm done. I can dump this way in about 5 to 7 minutes, depending on how thoroughly I rinse out the tanks. The macerator is quite powerful and will easily pump the waste to my home sewer drain located about 40 feet away slightly uphill in my garage. I use about 20 feet of 1 inch PVC pipe connected to my green discharge hose to be able to reach my sewer opening at home. For camping, I've never needed more than the 20 feet of green discharge hose that I carry. This can reach pretty much any dumping situation I've found myself in.
Blackwater Tank Treatments
Over the years we've tried many different blackwater tank treatments. For a while, we settled on an organic treatment consisting of "good" bacteria. The idea being that you nurture a healthy crop of good aerobic bacteria inside your holding tank and these will prevent the odor-causing bad anaerobic bacteria from growing. The good bacteria will also produce enzymes which help digest the waste inside the tank. There are several of these products on the market now. We used one called Eco-Save Dry Holding Tank Product . Although this product worked well for the most part, we did have a few episodes of bad smell from the blackwater tank, particularly if it was hot outside.
Lately (since 2016), we've been using a product marketed by Camco called TST Citrus Scent Ultra Concentrated RV Toilet Treatment, which can be found at Wal-Mart as well as on Amazon. We use the 4 oz. liquid bottles. I've been very happy with the results. We rarely get any odor, and if after several days of use some odor does pop up, adding a little more of the TST will quickly get rid of it. This product contains calcium nitrate, which prevents the bacteria-generated sulfides from being converted into hydrogen sulfide gas. It is this gas that causes the bad smell, so if you prevent it from forming, you prevent the septic odor. It really works. My wife has a more sensitive nose than I do and she won't let me use anything else. This product is also available in a packet powder form.