Waste tank needs cleaning

[The Dread Pirate Robert]

The waste holding tank on my Jefferson 42 should hold 40 gallons. Lately we have noticed it fills fast and needs to be emptied frequently. Today we went out past the discharge limit and emptied the tank. We also flushed it with sea water from the deck wash down hose then emptied again. I should mention that I have a clear tube from the exit point at the bottom of the tank to the masarator so I can visually inspect the fluid level.
We then poured 5 gallons of water down the deck waste plate and the water came to the top of my site tube. We discharged that to empty then poured in 2.5 gallons and it came half way up the site tube. Conclusion we have 35 gallons of solid what ever filling the tank.
What is the best product for dissolving those calcified solids so I can regain my full capacity?
Thanks.

 

[Comodave]

Ted, OC Diver had a good thread on this not too long ago. Try the search function and see if you can find it. If not you cam send him a PM and I am sure he cab point you in the right direction.

 

[Bacchus]

Here you go... good info
https://www.trawlerforum.com/forums/showthread.php?t=46357

 

[Giggitoni]

I don’t quite understand your “sight” tube setup. Do you have a “dip tube” that reaches the bottom of the tank? And do you pull from the top of the tank (ie dip tube) when pumping out? It’s possible that your dip tube, especially if it’s metal, has rotted off at some point near the top and you’re only pumping down to that point. Happened to me.

 

[The Dread Pirate Robert]

I installed a clear plastic tube from the bottom Suction fitting of the waste tank to the Suction end of the mas pump.

 

[O C Diver]

The only thing I would add to my thread on tank cleaning in your situation is to let the solution sit for a week or two and then let the boat roll in some beam seas before pumping out.

Ted

 

[HeadMistress]

I'd bet $1 that you don't even have 2" of "solid whatever" in the bottom of your tank...that the real problem is one of two things:

1. Your discharge fitting is on the top of the tank with a metal diptube that used to go to the bottom of the tank, but has been eaten through by urine and has either broken off at at about 35 gal level or has holes in it at about that level.

2. You have a seriously blocked tank vent--not the vent line...it's more likely to be a clogged vent thru-hull and/or the other end of the vent line--the vent fitting on the tank and/or that end of the vent line.

--Peggie

 

[The Dread Pirate Robert]

I will pm you with my address so you can send that $1.
My discharge is at the bottom of the tank with a 1.5” clear plastic tube connected to it going up to the maserator pump.
I removed the vent line from the tank fitting and am able to blow air out through the vent as well as into the tank.
Perhaps I should have mentioned earlier that this boat sat for a year with no activity and most likely a full partially tank Before I bought it. Upon possession I had it pump out at our first nights stop.
As said in my original post we emptied the tank twice to the point where no water was visible at the bottom of my clear site tube and were only able to pour 5 gallons of water into it before reaching the top of the site tube at the maserator.
We will be trying Teds cleaning procedure today with follow up posting.
Only kidding about the $1.

 

[rgano]

Good Luck! Hope you will fill us in (pun intended) on the eventual solution.