When is the holding tank full?

[Dave]

Hi,I just purchased a 1988 Hunter 28.5It is my first boat with a head.I've had a couple pumpouts without really knowing I needed them.How do you know when your tank is full and needs to be pumped out?

 

[Dennis Ferriello]

Acugage

Check out the HOW store for holding tank gauges so you will know when they are full. Also when you fresh water is low.Dennis

 

[Stephen Ostrander]

tank full

Unfortunately, with this particular model of Hunter, the holding tank is molded in under the aft berth, making it impossible to visual check and very difficult to install a gage. You have to figure out capacity, how many flushes, and approx. how much water per flush is used and do the math. (Peggie may have a better idea, but she may be having trouble with her server) You absolutely want to avoid overfilling and clogging your vent tube.

 

[Bryan C.]

Test it

Yes, don't use the overflow vent as the gage for determining if the tank is full, or else you'll get a spanking by Peggy, our head mistress. (On second thought, that doesn't sound half bad!)One way you can estimate capacity is the next time you pump out, see how many flush pump it takes to fill the holding tank (with just water) before it overflows, and then pumpout again. Then by using a systematic number of pumps when you flush, you'll be able to estimbate how many flushes for which you have capacity.

 

[Eric Lorgus]

Remember it's only the head that counts

Dave: Remember that it's only the head that drains to the holding tank, not the sinks, so fresh water usage and holding tank level are not directly related.I use a guesstimate based on the number of people who've been using the head. If I have four people on board for two days, I would definitely pump out upon returning. Most times it's just one or two people, and I often go weeks between pumpouts.Lastly, maybe you can try the test that Bryan suggested, and confirm the capacity of the holding tank. When I bought my boat, the surveyor wrote "25 gals" as the capacity, but here at HOW I've read many posts that assert it's only 12 gals.