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Hold Everything

Originally Published in MotorHome Magazine


Before you take your next RV trip, make sure the black and gray tanks are properly treated

There are so many things we love about the RVing lifestyle. Satisfying that traveling bone. Meeting new friends. And seeing the places that you used to only read about in magazines. There are few things better in life than gathering underneath the stars in the evening, and waking up to a spectacular morning in a new place, greeted by the scent of freshly cut grass or desert sage — and realizing there’s nothing on your agenda for that day.

But the one thing that can suck the joy out of every RV trip is holding-tank odor. It’s bad enough when it arrives like a malevolent ghost whenever you flush the toilet — but when it permeates the interior, you’ll begin to notice fewer and fewer accepted invitations to your social events. Maintaining a clean holding tank is not unlike taking care of your health — it’s a lot easier to maintain good practices every day than to make up for neglect later on. Most holding-tank odors are the result of improper and/or infrequent maintenance, so proper holding-tank treatment dosage along with the correct dumping practices are key to olfactory bliss.

Doing The Deed

Tanks A Lot

Dumping an RV’s holding tanks seems like a pretty simple process – and it is, if you know how to do it properly. The trouble is, many new RVers aren’t shown the basics from the beginning, and some learn the hard way that incorrect practices can result in rather unpleasant surprises. To prevent you from becoming another amusing story around the campfire, here are some helpful tips:

  • – Buy yourself disposable gloves and keep them, along with a bottle of hand sanitizer and some paper towels, in the utility bay.
  • – When using the toilet, it’s tempting to conserve water, but too little can cause buildup in the tank, making it hard to empty.
  • – When you’re camping with sewer hookups, it’s OK to leave the gray valve open, but NOT the black. Wait until this tank is around half full, then go outside and pull the handle. Leaving the valve open allows liquids to drain away, leaving solids behind.
  • – If you don’t have a black-tank flush, keep a 5-gallon bucket on hand. After dumping the black tank, open the toilet valve and dump a bucket full of water down – it’s a lot more sanitary than dragging the dump station hose through your rig or running it into a window. Repeat the process a couple of times if you have a larger holding tank. It doesn’t have to be full – just enough to rinse away leftover stuff at the bottom of the tank.
  • – When you’re finished, put about a gallon of water in the tank, and add some toilet chemical.








1. Get yourself a good hose with a 90-degree, threaded fitting like this one from Valterra. It will work with a variety of sewer ports, and even if the one you’re using isn’t threaded, having this fitting will prevent the hose from coming out when you dump and keep odor to a minimum.

2. It doesn’t really matter which end of the sewer hose you connect first. For our purposes, we started at the sewer port. Before connecting the hose, make sure the fitting on the end is properly attached, then turn it clockwise into the elbow until the pegs on the hose fitting are completely seated in the barbs on the elbow. As you can see here, the hose is not completely locked into the fitting yet.

3. Remove the sewer cap from the RV and attach the other end of the hose. You’ll note that we use a clear fitting, which may sound gross, but it allows you to see when the tank is rinsed completely clean, as it is here. If you’re hooked up at an RV park, open the black-tank valve only after making sure the gray-water valve is closed. Once empty, close the black-tank valve and either dump your bucket(s) of water down the toilet, or attach the dump station hose to the black-tank flush port, and turn it on. It’s a good idea to leave the black-tank valve open during flushing to prevent the tank from getting full and possibly rupturing. However, as long as you stay with the rig while running the water, it’s OK to close the black-tank valve, and open it after a minute or so (depending on the size of your holding tank, of course). Repeat this step twice.

4. Close the black-tank valve, then open the gray-tank valve. Since gray water is primarily soapy water from the sinks and shower, it helps to further clean the inside of the sewer hose.

5. Some dump stations may have a curb around the sewer port, which can make dumping a challenge. Keep a sewer hose support like this one in your storage compartment.

6. When you’re all done, wash your sewer hose thoroughly, and don’t put the water hose inside – it’s bad form. Hold the sewer hose up straight after rinsing to make sure it has no more liquid in it, then pull it from the port and thoroughly rinse the dump station with water so it is clean and ready for the next person.

There are dozens of holding-tank treatments on the market today, which can make choosing the right one for your needs daunting. The most important considerations are whether you prefer a natural/biodegradable product, or a chemical-based product that may contain formaldehyde, dyes and perfumes – an important consideration if you are sensitive to such additives. From there, it’s simply a matter of the delivery method: liquid, powder, or the most recent development, the drop-in (aka toss-in).

Because the choice of a holding-tank product is a very personal one, we’re presenting this guide to some of the most popular holding-tank products, in each company’s own words. Keep in mind that we can’t possibly cover every product each company makes, but a visit to any of these websites will reveal a multitude of choices.


camco-TSTTST: When you’re shopping for a holding-tank treatment, odds are that good value and long-lasting odor control are at the top of your list. Lucky for you, Camco’s original TST RV toilet treatment offers these benefits and more. Just four ounces treats a 40-gallon holding tank and controls odor for up to seven days — during any season. The product also breaks down waste and tissue, lubricates valves and cleans sensors. And, environmentally sensitive campers will appreciate that TST contains no formaldehyde and is 100 percent biodegradable. Retail cost: $6-$7 (32-ounce liquid).

camco-graywaterGrey Water Odor Control: When we think about holding-tank odor, it’s usually the black tank that comes to mind. But the truth is, the gray tank can also play an offending role. Months (or years) of food particles and grease can eventually build up, causing unpleasant smells to rise from drains throughout the motorhome. Camco’s Grey Water Odor Control is designed specifically to combat these issues by removing grease buildup in the gray-water tank, sink and shower drain lines. Just four ounces treats 40 gallons, and the end result is a fresh, lemon scent. Retail cost: $8-$10 for 64-ounce liquid.

Other products: TST Singles, TST Tabs, TST Drop-Ins, TST Probe Cleaner, TST Orange Power. Camco Manufacturing Inc., 800-334-2004, www.camco.net



Century Chemical

Travel-JonTravel Jon: Century Chemical not only makes holding-tank products for RVs, but for marine, aviation, charter bus and portable applications as well, so it’s safe to say they know a thing or two about odor control. The company’s Travel Jon product has a familiar blue color that is biodegradable and contains no formaldehyde. The highly concentrated formula (only 2 ounces per charge) helps break down waste and tissue, and the detergent component helps keep the holding tank clean. Retail cost: $14-$18 (128-ounce liquid); $5.99-$7.99 (dry). Other products: Travel Jon Waste Digester, Travel Jon Blue Max toss-in packets. Century Chemical Corp., 800-348-3505, www.centurychemical.com




dometicDometic is practically a household name, but it wasn’t until a couple of years ago that the RV giant introduced its own line of holding-tank products. One of its most popular offerings is its Premium Holding Tank Treatment, available in liquid and dry formulas. Aside from long-lasting, formaldehyde-free odor control (even in hot weather), the product’s additives break down waste and help tanks rinse cleaner during pump out. Retail cost: 32-ounce liquid, $10.94; 24-pack drop-ins, $24.99. Other products: 3 ’N 1 Bowl Cleaner and Tank Treatment, Clean ’N Green holding-tank treatment, Gray Water Tank Treatment. Dometic USA, 800-544-4881, www.dometic.com




Dry-Eco-SaveEco-Save Dry: Looking for an alternative holding-tank treatment product? Eco-Save Dry could be it. Eco-Save Dry is a bacteria/enzyme-based product that works in both black- and gray-water holding tanks, and contains no perfume or surfactants — just friendly bacteria that actually enhances the digestion of waste in septic systems. The environmentally safe, nonstaining product does not clean the holding tanks, but it does reduce solids and control odor. Plus, it is very economical — an 8-ounce jar of the product treats 30-35 tanks (not gallons) of waste. Retail cost: $25 (8-ounce jar). Other products: Eco-Save Original Formula (liquid), Eco-Save Fragrance Enhanced, Eco-Save Concentrate. Eco-Save products, 800-950-9666, www.eco-save.com




kronenKronen Premium Holding Tank Treatment: Why use chemicals that actually preserve black water, when you can break it down and eradicate it? That’s the question ProPack Packaging asks when referring to its Kronen product. Using a potent combination of naturally occurring microorganisms that are specifically engineered to break down organic materials, Kronen reduces the holding-tank contents to liquid and leaves behind a subtle, herbal scent. Kronen liquid is available in a 32-ounce size, a half-gallon jug, and a six-pack of 4-ounce single-use bottles. Retail cost: $32.99 for a 128-ounce jug. Also available in a pack of 10 Drop In’s for $13.99. Other products: Kronen Toilet Bowl Cleaner. ProPack Packaging,
888-260-1288, www.kronen1.com




monochem-T-5T-5: If you believe that experience counts, consider that the Monochem name has been synonymous with holding-tank products for the RV, commercial motor coach, aviation and marine industries for more than 55 years. Even if you haven’t used it, you’ve probably already experienced its benefits; this blue powder toilet chemical has been used to neutralize waste odors in recirculating and portable toilets since the company’s inception. The premeasured, 2.25-ounce, moisture-resistant foil packets are simple to use — just pour the contents of one packet into the toilet, and T-5 will immediately begin combating odor-causing bacteria. Retail cost: $15.95 for a box of six 2-ounce packets. Other products: T-5 NF (non-formaldehyde), Aqua-Toss toss-ins, Dyna-Bact toss-ins, L-10 liquid toilet chemical, L-10 NF RTU liquid toilet chemical, T-5 super concentrated liquid. Worldwide Monochem, 512-267-5190, www.satellite-environmental.com



TankTechsTankTechs RX: “The science of awesome” is how TankTechs describes its unique holding-tank treatment. Developed by a family-owned business that specializes in the pumping, cleaning and sanitizing of RV and boat black/gray holding tanks, TankTechs RX is a liquid tank treatment that uses probiotic organisms to remove odor and break down waste and paper to a liquid that contains healthy antioxidants. TankTechs RX also controls struvites (crystals that form when sewage breaks down). Retail cost: $39 for a 34-ounce bottle (68 tank treatments). Other products: TankTool RX. TankTechs, 800-625-7945, www.tanktechsrx.com



Thetford-aqua-kemAqua-Kem: If you looked up “holding-tank chemical” in the dictionary, you’d probably find a picture of Thetford’s Aqua-Kem product. Billed as the No. 1-selling holding-tank deodorant of all time, Aqua-Kem liquefies waste and breaks down tissue fast to prevent clogs, while powerful detergents clean tank walls and drain lines. Aqua-Kem works around the clock in all weather conditions, and although it contains formaldehyde, it is biodegradable and environmentally safe when disposed of properly. Aqua-Kem is available in a one-gallon jug, 64-ounce bottle, 32-ounce bottle, six-pack of 8-ounce bottles, and a three-pack of 8-ounce bottles. Retail cost: $10-$38. Other products: Aqua-Kem toss-ins, Aqua-Kem DRI.

Eco-Smart, Eco-Smart Free & Clear:Thetford-eco-smartThetford-eco-smart_freeandclear A kinder, gentler way to treat holding tanks. Original Eco-Smart uses a nonstaining, formaldehyde-free formula that quickly breaks down and liquefies waste and toilet tissue and provides odor control, while a detergent additive keeps tanks clean. Orange Eco-Smart is also nonstaining and uses an enzyme formula with a natural enzymatic deodorizer, while Eco-Smart Free & Clear offers the same benefits as the above but is fragrance-, dye- and formaldehyde-free and is 100 percent biodegradable. Eco-Smart products are available in liquid or toss-in form. Retail Cost: $16 for Eco-Smart Free & Clear 36-ounce liquid, $9-$12 for pack of 12 toss-ins. Other products: Drain Valve Lubricant, Tissue Digester, Level Gauge Cleaner. Thetford Corp., 800-543-1219, www.thetford.com



Valterra Products

valterra-odorlosOdorlos: Recently added to the Valterra family of products, Odorlos uses a sophisticated, natural technology originally developed in Scandinavia, Odorlos provides the naturally occurring bacteria with a continuous supply of the best alternative energy source to pure oxygen: nitrates. This eliminates the need for bacteria to target sulfate for energy, and the result is no holding-tank odor. Scent-free, formaldehyde-free and 100 percent biodegradable, all it takes is one ounce for every 10 gallons to prevent odor and break down waste and tissue. The product is available in a 168-ounce bottle, a nine-pack of 4-ounce bottles, a 40-ounce self-measuring bottle, a 68-ounce self-measuring bottle, a box of 10 4-ounce dry packets, a 6-pound tub of dry product, and a 10-pack of quick-dissolving drop-ins. Other products: Pure Power Blue, Pure Power Green, Pure Power Toilet Bowl Cleaner, Sensor Power Sensor Cleaner. Retail cost: $12.99-$38.99. Valterra Products Inc., 818-898-1671, www.valterra.com



Walex Products Company

walex-bio_bagBio-Pak, Porta-Pak: When you’re ready to leave on your next trip, just drop a single Bio-Pak into the holding tank and add water. The natural enzyme formula starts working immediately to control odor and break down solids. Packaged in a resealable slide-zipper bag containing 10 drop-ins, the formaldehyde-free formula also cleans sensors and lubricates valves. Porta-Pak, meanwhile, offers similar benefits and is now available in two fragrances: Original and Lavender Breeze. Retail Cost: $10-$13 for a pack of 10 Bio-Pak drop-ins; $9-$11 for a package of 10 Porta-Pak drop-ins. Other products: Bio-Active holding-tank treatment. Walex Products Co., 800-338-3155, www.walex.com



3X-nuGennuGen: Better living through science? Perhaps. NuGen’s 3X:Chemistry product is an advanced nanotechnology formula that creates a self-cleaning nano-shield on holding-tank walls, keeping waste in suspension while eliminating odors on contact. The fast-acting, “all-in-one system” cleans the tank and walls, breaks down waste and tissue, lubricates valves and cleans sensors. The formaldehyde-free liquid requires just 2 ounces to treat a 40-gallon tank. Retail Cost: $16-$20 for 20-ounce tip-and-pour bottle. Other products: Total Tank Bags, Total Tank Liquid, Total Tank Powder. 3X:Chemistry, 866-773-6136, www.3xchemistry.com





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