RV Holding Tank Care | Motor Sportsland Blog

What you need

RV Holding Tank Care isn't complicated, but it does reward having the right gear on the shelf before you leave the driveway. Most tank problems we see at the parts counter trace back to one of three things: the wrong paper, a tired hose, or tanks that got dumped too early and too often. Here's what we keep stocked for it, and what each piece actually does.

Toilet tissue that breaks down. Regular household paper holds together on purpose, which is the opposite of what you want sitting in a black tank. Camco's TST 2 Ply Toilet Tissue comes four rolls to a pack at 500 sheets per roll, and it's made for RV and marine holding tanks. It's fast-dissolving and clog-resistant, biodegradable, septic tank safe, and there are no dyes or perfumes in it. Camco also offers the same tissue in a one-ply at 280 sheets per roll if you'd rather use less paper per flush.

A second tissue option. Valterra's Softness Toilet Tissue is also a 2-ply, four to a pack, safe for septic systems and tested for rapid breakdown. Some folks like one brand's feel over the other, and both do the job of keeping the tank clear. If you've been buying grocery store paper and hoping for the best, switching is the cheapest fix available for a sluggish black tank.

A sewer hose kit. The Camco RhinoFLEX 15' Sewer Hose Kit comes with the fittings already attached, so there's nothing to assemble in a dump station lane. At the RV end there's a heavy bayonet fitting with four prongs for a more secure connection. At the dump end you get a detachable 4-in-1 adapter that fits 3" slip or 3", 3-1/2" and 4" threaded pipe, plus an elbow and caps. It's ready to use out of the box.

A tougher hose for rough ground. The Camco RhinoEXTREME 15' Sewer Hose Kit is built for harder use. It has superior abrasion resistance and crush protection, it won't dent or rust, and it won't crush if somebody steps on it. Pinholes and leaks are the usual way a hose dies, and this one is made to resist both. It's tested to withstand temperatures as low as -40F, which matters if you're boondocking in the Uintas in October. The kit includes a swivel elbow and a four-in-one adapter with swivel bayonet fittings.

A waste valve cap. The Valterra Waste Valve Cap in 3" black has reinforced ears for durability, and that's the part that usually fails first on a cheap cap. The cap is your last line of defense against drips on the road and the thing that keeps dust and critters out of the outlet. Caps crack, get left at dump stations, and go missing. Keeping a spare in the bay is a smart habit.

Grey tank treatment. Camco TST Grey Water Odor Control comes in a 32 oz bottle and goes after grease build-up in the grey tank and in the sink and shower drain lines. That grease is what makes a grey tank smell worse than a black tank sometimes. It eliminates foul odors and leaves a lemon scent. You only need 4 oz for a 40 gallon tank, so one bottle covers a lot of trips.

If you're not sure which fitting or cap size matches your coach, bring a photo or the old part into our Millcreek or Spanish Fork counter and we'll match it up. Guessing on sewer fittings is how people end up making a second trip.

Camco — TST 2 Ply Toilet Tissue 4 Rolls, 500 Sheets — Tst 2 ply toilet tissue 4 rolls, 500 sheets

Valterra — Softness Toilet Tissue, 2 Ply, 4/pk — Softness toilet tissue, 2 ply, 4/pk

Camco — Rhinoflex 15' Sewer Hose Kit W/ 4n1, Elbow, Caps — Rhinoflex 15' sewer hose kit w/ 4n1, elbow, caps

Camco — Rhinoextreme 15' Sewer Hose Kit W/ Swivel Fit, 4n1, Elbow, C — Rhinoextreme 15' sewer hose kit w/ swivel fit, 4n1, elbow, c

Valterra — Waste Valve Cap, 3, Black, — Waste valve cap, 3, black,

Camco — TST Grey Water Odor Control, 32 Oz — Tst grey water odor control, 32 oz

Doing the job

Start with the black tank, then the grey. The grey water rinses the hose out on its way through, which saves you some unpleasant cleanup. Connect at the RV end first, make sure the bayonet is seated and turned, then put the dump end into the inlet and weight it down or use a support so it can't jump out.

Pull the black valve and let it run until it stops. Close it, then pull the grey. When you're done, close both valves, disconnect at the dump end, lift the hose end over end to drain it, and cap the outlet.

Don't leave the black valve open while you're parked on full hookups. The liquid drains away and the solids stay behind, and that's how you build the dreaded pyramid. Keep the valve shut and dump when the tank reads about two thirds full so there's enough water to carry everything out.

After dumping, add water back to the black tank before you use it again. A few gallons at the bottom is the whole trick. Add your treatment, use RV-safe tissue, and the tank mostly takes care of itself.

How often RV Holding Tank Care matters in Utah conditions

Dry air and hot sun work against you here. Our summers bake the tank and the dump valves, and low humidity means any moisture in the tank evaporates fast, which concentrates waste and makes odor worse. Dump at two thirds full on every trip, and refill the black tank with water afterward. Don't stretch it to three or four weekends because the tank "isn't full yet."

Treat the grey tank on the same schedule you treat the black. Utah water is hard, and between that and cooking grease, the drain lines in a grey tank film up quickly.

Freezing nights are the other half of it. In the fall and spring, overnight lows in the valley drop well below what daytime temperatures suggest. Never store a loaded tank through a cold snap. Dump it, and if the rig is sitting for the season, come see us about winterizing or let our service department handle the full job.

Check your hose every few trips. Hold it up and look for pinholes, check the gaskets at the bayonet, and replace it before it fails at a dump station. The same goes for the valve cap. A cracked ear means a new cap.

Frequently asked questions

Can I use regular toilet paper in my RV?

We don't recommend it. Household paper is designed to hold together, and in a holding tank that turns into clogs and sensor problems. Both the Camco TST and Valterra Softness tissues are tested to break down quickly in RV tanks.

Why does my grey tank smell worse than my black tank?

Grease and soap residue coat the inside of the grey tank and the drain lines, and that film goes rancid. Camco TST Grey Water Odor Control is made to remove that grease build-up in the tank and in the sink and shower lines.

Should I leave my black valve open at a full hookup site?

No. The water drains out and the solids pack down into a pile that's hard to clear. Keep the valve closed and dump when the tank is about two thirds full.

How do I know which sewer fittings fit my RV?

Bring the old part or a clear photo of your outlet to our parts counter in Millcreek or Spanish Fork and we'll match it. We'd rather spend two minutes checking than have you drive back.

What should I do with my tanks before a hard freeze?

Dump both tanks so there's nothing sitting in them, and don't store the rig loaded through cold weather. If you're putting the coach away for the season, talk to us about winterizing or have our service department do it.

Parts in this post:

Order now: call our parts counter at 801-262-2922, or stop in at either store, Millcreek in Salt Lake City or Spanish Fork. Browse all our RV parts and accessories.