Back in early 2012 we began using Rid-X septic system treatment in our black water tank. Prior to that we always used Thetford Aqua-Kem. Both have their place, advantages and disadvantages. I'll recall my experiences here for others to consider. I hope you find the information helpful.
The reading room showing tank treatments and mascot.
Aqua-Kem is made by Thetford Corporation
and is a formaldehyde based product. It provides the best odor control and is reasonably good at breaking down sewage. Aqua-Kem, however, doesn't seem to break down the sludge that clings to the tank behind the level sensor. This interferes with the sensor's ability to read the tank. You'll get false high level readings which is slightly annoying.
Thetford also makes a level gauge cleaner which is added to a half full tank before travelling. The sloshing around action created by a moving vehicle provides mixing and cleaning action. We've found this to work only sometimes. And the bottle of level gauge cleaner is expensive.
When you push the button it's anyone's guess what reading comes back.
The other device that we've used is a cleaning stick. This works pretty well and I think it's a good idea to do this periodically. The end of this stick sprays a ball pattern so everything inside the tank gets washed down. If you heat the hose with a hair dry, it easily bends and goes around corners. It's perfectly smooth so there is no chance for a snag either on the way in or out. Hook a garden hose to it for the water supply. This flushes out a lot of stuff that the Santi-Flush seems to miss.
We call it the douche rod. And it works great!
Even after all this flushing, cleaning and treatments we still have sludge and false readings coming back from the tank level sensor. This led us to explore an enzyme based product. Someone recommended trying Rid-X
which we did. At the time of this writing, we've used this product for about 6 months. It worked very well for eating up the sludge on the inside of the tank. After the second Rid-X treatment the level gauge began to work normally again. The recommended mix ratio is 8 oz of the product for up to 1500 gallons of tank capacity. Keep in mind this isn't an RV specific product but a domestic septic system treatment designed to avoid backups. I used a 4 oz charge for two cleaning cycles then backed off a little bit. You could probably use just a cap full or two in a RV sewage holding tank owing to its small size compared to a septic system.
What I didn't like about this product (Rid-X) is the sewage smell that begins to develop when sewage levels reach about 75% or more. This was more pronounced over the summer in warm weather. But it was always present to a greater or lesser extent.
Capacitive tank level sensor. It can't read through sludge.
And most noticeable in the bedroom. This isn't a smell that would knock your head off, but a definite sewage background odor. Not good when the company shows up.
Aqua-Kem has been a great product in that we've never had any sewage odors at any time. We charge 8 oz to the tank. Of course Aqua-Kem contains formaldehyde which might upset some. I would direct them HERE
to learn the facts about this chemical, its usage and impacts. It isn't the environmental monster you think. Aqua-Kem doesn't seem to keep tank side wall sludge under control which is a bit of an inconvenience.
So what we do is use both of these products and do a spray cleaning periodically. That is up and beyond the Santi-Flush which is done every cleaning cycle. For us, odor control is more important than having the gauge read properly. So we use the Aqua-Kem as our primary tank treatment. And when the gauge begins acting up, we'll do a Rid-X dosing. Usually one Rid-X session cleans off the sludge.
The sewage soil stack. This location stinks.
As for Rid-X odors, we haven't explored any odor control supplements that might eliminate this problem. I would be interested in what others are doing to curb odors. We have no odors with Aqua-Kem.
Thetford's 1 gallon Aqua-Kem @ Camping World - $32.00
Rid-X 48 ounce septic treatment @ Amazon - $20.00
Complete slide show HERE
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