Holding tank

[Steve A]

My wife and I are on a two week cruise in ME. My holding tank fills in less than 24 hours. Big problem! It had been making it for two days (or three with just two of us) with no problem. I emptied it yesterday and inserted a dip stick to see if there was anything left in it. Appeared to be empty. Full again now. I am befuddled. Seeking the wisdom of this admirable group.

Steve
Jester
Hull 160

[KenKrawford]

Steve the only way anything gets into that tank is when the flush button is pressed. I've you've verified that it's truly empty when pumped (I assume you're pumping or this wouldn't likely be much of a problem), then someone must be leaning on the flush button a bit longer.

[Lulu]

Sometimes there starts to be buildup of waste in the bottom of the tank that pumps cannot suck up. That overtime will displace liquid waste and cause this problem.

I would pump out and then put a water hose down in from the deck and just make sure you are stiring up anything that may be building up in there.

If that does not solve the problem I would evaluate the use of the head chances are someone is over flushing / rinsing then using the head.

My personal experience is guest will tend to fill the bowl with water to do #1 waste of water and tank space then they over flush

Happy flushing

You don't need to fill

[wcconway]

There is a silver small vent outside the holding tank on the hull. Ours got clogged by salt and gunk. Simply use a flathead screwdriver or something else to scrape the gunk off. When the holding tank starts venting again, all is well.

[Fat Cat]

The holding tank on our boat has, as far as I can calculate, has never worked as designed. It seems to get worse with time. There is no way two people are filling this 22 gal. tank in 24 hours. I have noticed lately that I can "burp" the tank by opening the drain valve momentarily and that will make for a little more room in the tank. By "burping", I mean you can hear a rush of air before the tank actually starts emptying. Now I'm thinking the air vent may be all or part of the problem. Attacking this air vent from the inside is hopeless, as there is no room to do anything without removing the bowl and then the cover behind the bowl as the holding tank might be removed. The exterior of the air vent has a fine bug screen covering the opening. Any ideas? Can I permanently destroy the screen in order to fish a wire (or similar) down the vent tube to see if it's blocked? Or is it worth the effort to remove the holding tank in order to access the vent pipe inside the holding tank cavity?

[JohnNorton]

Fat cat: I had a similar issue, I expect started when I had a full to overflow holding tank. Solution was to place a hose over the vent on the outside of the hull and force water back through the vent tube. A short blast or two apparently open the vent tube.

[sargentef]

Ditto to placing garden hose over haul vent and back flushing vent hose!
"Seawing" hull# 309

[Fat Cat]

I tried flushing the air vent with a hose some time ago with no improvement. Our marina has lots of water, but not great pressure. Maybe I should try it again and try to maintain a better seal, hopefully to get the full effect. What do you think of that bug screen? Is it truly necessary? If it was gone, I could probably snake a wire (or similar) into the vent and to the tank. What self-respecting bug would want to make a home in there??

[zman18]

We had issues with sediment in the bottom of the tank that effected capacity. We got a box of septic tank cleaner from Walmart and after pumping out the tank, we added a few gallons of water and a small amount of the cleaner. After leaving it in the tank for a couple of weeks pumped it out and have not had any problems since.

[sargentef]

We have mud wasps in our area, they seem to find small tight areas to build their nests and can cause a mess/ problems. I would not destroy the bug screen for this reason alone.

"Seawing" haul# 309

[Fat Cat]

This is a follow-up post to my previous one that was about a quickly filling holding tank... thanks to several members who suggested some fixes. First off, I've always flushed with sea water thinking that closing the head seacock would harm the pump/macerator. It not only doesn't seem to hurt it, the toilet has never worked better. Also, I assumed by calibrating the tank when empty, it would brilliantly know it was full. It doesn't. It was suggested to me that I should meter in 20 gallons by flushing it into the head. I didn't have a measured bucket at hand, so I went for broke and flushed MANY full toilet bowls of water. I was shocked at what this holding tank could take! As I was flushing, I went outside to view/listen to the air vent. After a zillion flushes, air and water sputtered out the vent. This proved to me the vent wasn't plugged. I then calibrated the tank monitor to "full".

Results: I now know the tank can handle what it was designed to do. My air vent is not plugged. The macerator has never been quieter, not sure why, but it likes fresh water, I guess. And I suppose that's the down side - is the use of fresh water. The way we boat this is not an issue for us.

[nybor]

Boy, I never thought a toilet could cause so much trouble. On our trip to Cuba, I opened the tank drain and ASSUMED it was draining. HA! After awhile, the toilet wouldn't flush. When we got to the Marina, i carefully unscrewed the holding tank deck access...... (note to all, the tank is plastic and hence is flexible.......) Has anyone ever seen a S_ _ _ volcano? Yikes. Anyway, after cleaning the deck and me, we made it back to Key West and pumped it out. However, then we noticed that it was not drawing in raw water into the toilet bowl. So we gave up.

I think the vent is clogged and I will check that first. I also think that maybe the drain is clogged and will try that septic cleaner idea. But has anyone had the problem of the water not filling the bowl? It worked for 8 days and then stopped.

_%_$%_$%*_+$*%_ ok, i feel better now.

thanks

dave / NYBOR

[Triumph]

I have had to swim under the boat and stick a flex rod up the drain to unclog the tank exit. Be prepared to swim like hell and obviously do this out in open water not in the marina.

Bill on Triumph

[zman18]

Been there with our tank. Go to Home Depot and get a plumbers snake. If you have a dingy you can move to the side of the boat by the drain hole. The snake can be inserted without getting in the water. Pull the snake out of the holder and use the thin end, it will fit in the hole and a couple of pushes with usually get things flowing. To eventually solve this issue we got some septic tank cleaner (Walmart) and used just a little in a drained tank and some water. Let it sit or a couple of weeks then drained it out. Have not had a problem since.