Welcome to RVing and the various opinions that we get when asking questions. I am not sure why your dealer told you that you need a macerator to dump your waste tanks, but he did and you bought one from Amazon (and he apparently was not trying to sell you one) and now you have it so you might as well use it. My RV came with a macerator as the only way to dump. I do not have the standard gravity feed connections that most have. Your portable macerator has one advantage over my built in macerator and that is the hose connection that you are asking about. You use that connection to attach a non-fresh drinking water hose (in other words a standard garden hose) to a water spigot - not on your RV but at the campground or home - to clean out the hose you are dumping from and also flush out the black tank which will help you prevent things that get caught up in there staying in there. When you flush anything that did not come through the dump should get flushed out - which is a good thing and such a flush is sold for gravity hoses too for the same purpose. You can dump your tanks with the macerator without having to do the flush. Just leave the hose connection closed. I wish I had the ability to back flush my black tank through my macerator but my RV is not designed to allow that.
As to a backflow - this prevents dirty water from going back into a clean water source - the spigot in this case. If your Flojet does not have one built in - and likely does - you can buy one that attaches to a garden hose at Lowes in the plumbing department. Just explain to them that it is connecting to a garden hose.
Your macerator will pump the waste out of your waste tanks. This is something that usually gravity takes care of but if the dump hole is uphill or for some reason higher than your hose outlet, the macerator makes it possible to dump. As I said, this is all that we have. We find it fast and easy to use. You can also dump by connecting a standard waste hose directly to your trailer dump connection and then that hose to the dump hole without using the macerator. This is up to you. Many like the macerator. Be aware that with a macerator you want to avoid getting things like hair in it. So if you are using the shower in your trailer and a lot of hair goes down the drain, you may jam the macerator's impeller.
Two years ago I, too, was new to RVing. By experience and asking questions on forums like this, I learned a lot. Sometimes you actually do get helpful and full answers to questions here.
Ok, since I have a flo-jet portable when I use when conditions require somethig more than the 3" hoses I carry,
There are two hose fittings, the male fitting gets 1" (3/4 can be used) BLACK rubber hose to the sewer inlet in my case that can be 40-50 feet distant and even slightly higher than the outlet on the tank You do not need hook up any other hose. HOWEVER......
Once the tank is empty THEN you can hook up a fresh hose Make sure there is a vacuum breaker device.. I use a GREEN or Clear hose for this. and shoot some fresh water into the pump housing to rinse it, KEEP THE PUMP RUNNING when you do this. Send in enough that you pump fresh water out the other end.
I have had to go over 50 feet a few times to reach ye old hole in ground.. I can do this. But thankfully, not often.
Why a BLACK rubber hose? Well the rubber hoses are more flexible in cold weather and Black hose.. Black water.
(I have a gray hose too rig has 2 Gray tanks one is remote)
WHITE is drinking (Potable) water hose. It is NEVER hooked to either the tank flush or the macerator without the rinse hose (Green or clear) between them, And the clear hose (The one I use) has both a spring check and a vacuum breaker on it. (Yes, I know, belt and suspenders, Times 2 when flushing the tank itself since the motor home has both a spring check and a vacuum breaker as well).)
Home is where I park it.
Kenwood TS-2000 housed in a 2005 Damon Intruder 377
No but the hose I use to rinse the portable macerator does have a back flow prevent-er!
The Flo-Jet does have a female hose fitting inlet for back flushing/rinsing, I sometimes connect a hose from pedestal to that to rinse pump and hose after pumping poo to tank in back of truck.
and most pedestal water spigots do NOT have a back flow protector.
Just another reason I don't think these should be used in CG's.
1* 2008 Brookside by Sunnybrook 32'
1* 2002 F250 Super Duty 7.3L PSD
Husky 16K hitch, Tekonsha P3,
Firestone Ride Rite Air Springs, Trailair Equa-Flex, Champion C46540
"A bad day camping is better than a good day at work!"
I have seen a couple of times at the camp sites where the dude has a empty BLUE tote sitting in the back of his pickup truck. He then connected the FLO-JET to the waste connection of the trailer and pumped the waste water up into the blue tote. When it got full then he disconnected the 3/4-inch hose from the trailer end and tied it off high on the truck and headed for the dump site. AT the dump site he let gravity flow empty the blue tote using the 3/4-inch hose...
Sure was an easy NO-MESS way to carry off the waste water at the camp site.
Would concur with most of the posters here. In most situations gravity will do a fine job at a GC with hookup. But I own a flojet and find it really helpful for dumping at home or places I can't reach a hookup with a standard stinky slinky. I have 2 dedicated hoses for the pump. I have an oversized "brown" hose for the outlet, and a standard yellow water hose for the flush inlet. I also have a dedicate clear 45 elbow to connect the black tank to the flojet. This lets me get a visual to know when to shut the pump off, and is really helpful with the back flush to know when it's clean. I keep the pump, and dedicated hoses in a dedicated spot in my barn and they are never are used for anything else. I have also seen built in macerator's on some units where the bath is on the camp side to push everything to the hookup. The ACE 29.2 is a good example.