Cleaning the holding tank sludge

[sailcapt340]

Has anyone any tips for cleaning out the sludge at the bottom of the holding tank?
A recent clog in the waste line from the toilet had me removing the line from the tank to be able to snake out the line properly. Now all is running well.
On the other hand, the tank indicator does not fall completely to the zero level, which has me believing that the same hard sludge is at the bottom of my tank, keeping the float from falling to the bottom. The macerator runs fine and will discharge any waste from the tank, but I still feel there has to be a build up at the bottom.
I do flush the tank every time I pump out, but is that enough to keep it clean?
Thanks for any tips or procedures.

 

[capejt]

Just a purely uneducated, untried thought here, but I recently saw an ad on TV for RID-X. Apparently they now make a version of their product for RVs. I got to thinking, why wouldn't this work in a marine holding tank? Of course like I said, I haven't done any research, and for all I know this stuff might eat away at a marine holding tank or something else bad. Has anyone else heard of this?

 

[py26129]

Has anyone any tips for cleaning out the sludge at the bottom of the holding tank?
A recent clog in the waste line from the toilet had me removing the line from the tank to be able to snake out the line properly. Now all is running well.
On the other hand, the tank indicator does not fall completely to the zero level, which has me believing that the same hard sludge is at the bottom of my tank, keeping the float from falling to the bottom. The macerator runs fine and will discharge any waste from the tank, but I still feel there has to be a build up at the bottom.
I do flush the tank every time I pump out, but is that enough to keep it clean?
Thanks for any tips or procedures.

Did the gauge ever fall completely to the zero level? Many gauges are not that accurate. Is there any way to you to visually inspect the tank? Mine is made from white plastic and with a light behind the tank I can usually get a pretty good idea of how completely it has been emptied. If you cannot visually inspect the tank, then you have 3 choices.

1. Fill the tank about 1/4 full and go out on a rough day and agitate, then pump out.
2. Cut an inspection port into the tank and go from there
3. Don't worry, be happy

Cheers

Matt

 

[Sailvayu]

First thought is the sending unit is stuck and will not go all the way down. I would pull that and clean it first. I like the rid-x idea as well and have been thinking of trying that myself. I did not know they had it for RVs so I will have to look into that.

 

[sailcapt340]

Pulling the sensor

I did plan on pulling the sensor out this week to just check that it was moving free. That will give me the opening to see in the tank at the same time.
I didn't know about the Ridx either. Might be something.

 

[John T1594]

Sludge

I'm not sure where I found this but it was filed away in case I ever needed it:
To remove holding tank sludge build-up: Add two cups of Calgon Water Softener to one gallon of hot water and pour into tank. Add one cup of liquid laundry detergent to one gallon of hot water and add that to the tank. Let sit for several hours, then fill the tank with water and let that sit for a few more hours. Pump out tank and rinse a second time. It probably would not hurt to slosh the tank around a bit with a trip out and back.

 

[Scott B]

Best advise from Peggie Hall

http://forums.hunter.sailboatowners.com/showthread.php?t=107140&#post618140

and her book has lots of good advise.

http://shop.sailboatowners.com/prod.php?53615

 

[Rocket1]

Not a fun task....

The PO of our boat wasn't too regular about pumping out the holding tank, so we inherited a tank with a significant "hockey puck" in it, as well as a level guage that didn't work. I pulled the sending unit and cleaned it (was serioiusly plugged up), and then tried a multitude of chemicals and snake oils in an effort to break up the "puck". None with any notable success.

I finally took the plunge (not literally) and installed a 6" inspection port in the top of my holding tank. This allowed me space to get into the tank with a hose nozzle to break up the gunk. While I sprayed and held my breath, the Admiral held the pump out nozzle on deck. While a ton of work, I can say that about 200 gallons of water later - the tank was clean.

I still have to replace all of the hoses, but that's for another day.

 

[splax]

Hello,
I think coffee grounds might be a good thing to put down the waste outlet
They seem to do a good job on the toilet bowl at home, when I am cleaning the French press. I think the acidic nature of the coffee is the thing.
I am thinking if they scrubbed around while underway that would be a good thing. I tried to contact Peggy to run it by her, but had no luck.

 

[Don Lucas]

I think adding extra solids like coffee grounds to your tank is a poor idea!!!!!!!

 

[wufibugs]

I thought some of those enzyme based additives worked on the hardened residue that comes from long deferred maintenance. Those bacteria can be voracious little devils. Maybe a little steak sauce to encourage them?

 

[thinwater]

Flush with more water volume. Folks flush until the bowl is empty, but really need another 6-10 strokes after that. The extra water really helps. This is just a matter of following the instructions.

Nitrate and enzyme based products really help. I did 3 years of side-by-side testing for PS, and the tanks with the treatments contained nothing that didn't slide right out. Those with no treatment, and worst those that had used veggy oil on the head, contained sludges.

And Peggy's advise is sound, as always. Conservative, but effective. Better than forum chatter!