What does a 10 gallon holding tank translate to?

[Capslock118]

Hi,

So we are getting closer to trading our motor boat for a 25' bayfield.

She comes with a 10 gallon holding tank for waste.

Let's say for argument you go out once each week from 9am to 5pm, eating and drinking throughout each trip.

What, exactly, would a 10 gallon tank amount to? A pump out after every other trip? every week? month?

we are a fairly green family I would say, but measuring stool is not something we've ever done

[zz4gta]

Just think to yourself, how much you crap. Assume everyone will poop once everytime you go out (that's a lot) and add it up. Most people won't crap on boat, I know I try not to, mostly b/c we're underway, I don't do a lot of anchoring. So the above formula will be worst case scenario. I would think that even with pretty substantial crapping, that you could go a couple months w/o a pump out. That's 8 trips, which will include urine, poo, and waste water.

Put it this way, when it doubt, pump it out. I've seen first hand the consequences.

[N0NJY]

/chuckles

What does a 10 gallon holding tank translate to?

I'd say roughly, 10 gallons.

[jimq26]

You would be wise to consider a 6 gal MSD Thetford unit which will hold about 63 flushes.

[olson34]

Joel,
It is not just the waste, but the total amount of water that goes into the tank with each "flush."
My advice would be to pump that tank completely empty at your local pump-out station. Then open the cleanout port or at least station someone to put their ear or a stethoscope against the tank so that they can hear the splash of water into it. Then, flush the head and count strokes until the splash is heard inside that tank. Count strokes, and remember that you have to move all waste thru the hose run to the tank so that no waste is left inside that hose. Just removing waste from visibility is not sufficient. If unsure just how much liquid is moved per stroke, close the intake valve and flush with measured amounts of water from a quart or gallon jug.
You might find that as much as two gallons of total waste and follow-up water is needed to clear out the plumbing system each time the head is used....

"YMMV"


L

[sawingknots]

i wouldn't avocate using a bucket anywhere except offshore but i do know that during malfuctions many large cities dump raw sewage [lots more than 10 gallons]

[bljones]

We have a 10 gallon holding tank on Whiskeyjack. With two adults aboard during the week and occasional weekend guests, with careful water conservation, we can go 2 weeks between pumpouts. If you are weekending, a 10 gallon holding tank will mean a pumpout every month or so.

[rmeador]

My holding tank is between 5 and 10 gallons, I think. I don't know a good way to measure it since it's mostly out of sight and inaccessible, but the maximum space it could be is less than 10 gallons by eye, and I doubt it uses all the space. The head gets used probably two times a day on average. I'd estimate a single use is somewhere around half a gallon including flushing (this mostly agrees with my estimate of tank size). I need to have it pumped once a week. I've made it two weeks, but towards the end when it's getting very full I become very cautious about going to the marina bathroom whenever possible.

[chef2sail]

Ration food and water....

Your requirement will be directly proportional to the amount of food and water you and your crew consume.

Our 24 gallon tank is usaually good for 4 weekends ( Fr-Sun ) for my wife and I. When docked we very rarely utilize our holding tank and use the marinia/ club. Our club has a pumpout also which comes to you boat for a minimal charge so it is easy to maintain.

To prevent clogging your vent hose and overfilling I will get a monitoring system so you know when the tank is filled. There are a few which can attach to the outside of the tank as long as it is PVC.

We have a SCAD monitor

Dave

[klem]

I worked on a boat with 25-30 people on it and we would generate about 100 gallons of black water per day or about 4 gallons/person/day. This was with pressurized water so people may have flushed a bit more and we were always out for long periods of time.