A Holding Tank Question

G

gcolton

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Can holding tanks accumulate undissolved solid materials in the bottom?

Ever since I purchased my boat I have felt that the holding tank did not have the advertised 6 gallon capacity. I have just thought about this again as I had a malfunctioning water inlet valve and in trying to determine just what was wrong I filled the tank to the point where the shutoff sensor (the sensor that shuts the tank vacuum down when full) came on.

I started with an empty tank and it did not seem to me that I ran much over two gallons before shutoff occurred.

If there are built up solids in the tank is there any thing recommended to dissolve these?

George
 
yes

if you have a fairly straight acess you can use a rv tank cleaning spray wand. Carefully
 
If you do not have a straight access, consider installing a tornado. Pouring some Calgon and filling the tank 1/2 full with water and taking a ride in the boat will help dissolve and dislodge them as well.

--Edit Add--

If you have a large enough vent pipe, you may be able to attack the problem from both ends. I had a similar problem with my Regal. The vent pipe was large enough to put a garden hose in and did not have a filter. I pumped the tank while back flushing it via the garden hose. It took about 20 minutes to get the water coming out of the site glass clear. I was amazed at how much stuff had stuck to the tank walls.
 
Unless you downsized your holding tank a Pursuit 3000 Express should have an 18 gallon holding tank.
 
Is this something that would be inserted down the pump out tube or through the toilet? I do not think I could get to the tank from the toilet.

George
 
Empty your tank. Then use measured containers to see how much goes in before it gets full. A six gallon holding tank is probably good for 6-12 uses before its full.
 
inserted via the pump out deck fitting or inspection or gauge plate on top of the tank. Less desirable would be a flex hose with a small opening fitting on the end inserted into the tank and allowed to thrash about. I wouldn’t want to touch it when it came out but you do what you must.
something like there might fit the bill:
http://www.rvpartscenter.com/RV_Parts/rv_holding_tank_wand.htm
 
Thanks Bruce.

Now, is the new inlet valve would just arrive. I have to go to another marina to get a pump out.

Tried the macerated, onboard pump out the other day and nothing happened. I could tell the pump was running but no action. That is one reason I think the bottom of the tank is a solid mass.

I have no idea of how previous owners used or treated the system. In the over two years I have had the boat the head has only been used two or three times. No solids.

George
 
"I have no idea of how previous owners used or treated the system. In the over two years I have had the boat the head has only been used two or three times. No solids."

That's probably your problem right there; what WAS in the tank has dried into a solid cake. I think filling the tank 1/2 full or so and letting it soak for a week would help, then try the methods outlined above.
 
quote:
Originally posted by stmbtwle

"I have no idea of how previous owners used or treated the system. In the over two years I have had the boat the head has only been used two or three times. No solids."

That's probably your problem right there; what WAS in the tank has dried into a solid cake. I think filling the tank 1/2 full or so and letting it soak for a week would help, then try the methods outlined above.

Click to expand...


I did the soaking in the past to no avail. It has now been soaking for over a week and I will try to see if I can clean it any.

George
 
quote:
Originally posted by stmbtwle

"I have no idea of how previous owners used or treated the system. In the over two years I have had the boat the head has only been used two or three times. No solids."

That's probably your problem right there; what WAS in the tank has dried into a solid cake. I think filling the tank 1/2 full or so and letting it soak for a week would help, then try the methods outlined above.

Click to expand...


+1

If it's a solid mass, you need a chemical or force to break down the mass.

One of these might do the trick. BF sells them

LINK to Raritan
 
What about the old trick of Calgon and a bag of ice or two? Then go shake it up.
 
quote:
Originally posted by Shake n Bake

Unless you downsized your holding tank a Pursuit 3000 Express should have an 18 gallon holding tank.

Click to expand...


You are correct. I was thinking of the water heater.

This means there is more solid mass in there than I was thinking.

G
 
If you can pump it out, then the mass is on the sides. I would second the Calgon and ice cubes.
 
I guess that I have to do this Calgon and ice trick on a day when the bay has a lot of chop.

Just what does the ice do in this equation?

G
 
"what does the ice do"

Acts as a "scrub brush", then conveniently melts for easy removal.
 
Out of ignorance, I have to ask! Would a blocked vent cause the same reaction?
 
"Out of ignorance, I have to ask! Would a blocked vent cause the same reaction?"

It might, or it might result in a collapsed tank; depending on how much vacuum the pumpout system can generate.

Might be something to check...
 
quote:
Originally posted by gcolton

Can holding tanks accumulate undissolved solid materials in the bottom?

Ever since I purchased my boat I have felt that the holding tank did not have the advertised 6 gallon capacity. I have just thought about this again as I had a malfunctioning water inlet valve and in trying to determine just what was wrong I filled the tank to the point where the shutoff sensor (the sensor that shuts the tank vacuum down when full) came on.

I started with an empty tank and it did not seem to me that I ran much over two gallons before shutoff occurred.
Click to expand...
While solids could build up, I can't immagine four gallons of sludge in a six gallon tank. And as someone else posted, your tank is probably much larger than six gallons capacity.

A few thngs come to mind:

The tank sensor is faulty, the tank is not really full.

The vent is plugged.
 
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