Two Problems with my Holding Tank

[Richard Lanas]

I am told that the holding tank on my 35.5 Hunter Legend has a 14 gall. capacity. I calculate that this should be enough to use it 24 times (28 would top it). Nonetheless, three weeks ago liquid waste--with its wonderful odor--began to come out the air vent, suggesting to me that the tank was full. We had only used it about 15 times.Question # 1: Since I pump out every time I go out, is it possible that pumps do not get rid of all waste. If so, what percentage of waste is usually pumped out with these pumps?Question # 2: I use a lot of K.O. to get rid of odors. The fact that odor comes out through the air vent, does it suggest that K.O. is not doing its work properly? Anything else I should be doing?

 

[Jim Rushing]

35.5 Holding Tanks

Richard, a 35.5 holding is big enough for two people for one weekend. If it is used only as a night time unit, it will take two weekends to fill it. Snake River makes a probe for the 35.5 metal holding tank that connects to their gauge. It will allow you to pump before it dumps out the vent.Jim Rushing

 

[Peggie Hall/Head Mistress]

How did you arrive at 24-28 flushes?

I'd say 20 tops...and that's only if you're VERY frugal with flush water. Btw...how are you keeping track...hash marks on the wall? Take a number, and when all the numbers are gone, the tank is full? A sign-in sheet for the head??? I suggest you install a tank level monitor that lets you know what the level is in the tank before it's full, so you'll have time to find a pumpout. The Snake River AcuGage is the system Hunter is now installing as OEM gauges...and IMO, the best on the planet 'cuz the contents never come in contact with the sender.Unless your tank vent is blocked--in which case, the pumpout wouldn't remove more than a gallon or so before it pulled a vacuum and couldn't remove any more--your tank is being emptied. However, because the pumpout loses prime when it reaches the top of the discharge fitting in the tank, there's always about an inch left. But that's not enough to make the difference between 15 and 24 flushes! If you get odor out the vent, your tank isn't getting enough oxygen for K.O. to work. You said you use a LOT. I've always found it interesting that so many people never seem to understand that if there isn't enough oxygen for the recommended dose to function aerobically, adding more doesn't increase the amount of oxygen, it just puts more bacteria in the tank that can't function aerobically. Try Odorlos instead.

 

[fred miller]

Had the Same Problem on My 35.5

Rich;This is really coincidental. I had the same problem on my 1992 35.5. First its a 13 gallon tank not 14 gallon; but a gallon more or less is of little consequence. When my tank got full I noticed an odor eminating from the aft cabin. I have an inspection hatch for my holding tank so I checked for tank and hose leaks while my wife pumed the head . .none to be found.Yeah![by the way, its the original aluminum tank]. On flushing I noticed "stuff" coming out of the vent each time the toilet was pumped though.It was indeed full, the marina forgot that week to pump me out although they claimed they did.Pumping it forced "stuff" out of the vent. very unattractive on the side of the hull. So I had the tank pumped and flushed it out with a gallon ot two of fresh water. But still some smell persisted. A friend told me this trick . .Get a turkey baster or battery water filler bulb type gizmo. Fill it with KO and force it down the vent from the outside of the boat. This squirts KO down the vent tube into the holding tank killing any residual odor along the way. It worked great. Now I follow that procedure in addition to adding KO through the toilet after each week end. Fred Miller S/V M Squared.

 

[Richard Lanas]

About My Holding Tank

Peggy, Jim, Fred: thank you for your observations. Quite interesting and wise.Peggy, one more thing. Assuming my tank vent is not blocked, is there any thing one can do to increase the amount of oxygen in the tank?thanks again.