holding tank

[workingonadream]

Good morning all. my indicator light was coming on shortly after being pumped out this season, so after a search on this site, I figured it was a rotted out pick up tube in the tank that I was going to tackle next month However, some weird things were happening, such as I would leave the boat for a weak after being pumped out and come back to the light being on. this weekend, the light came on and when I came back several hours later, it was off. Has anyone ever had a similar issue. i'm thinking that it might be an issue with the sending unit AKA Fart Sniffer. Thank You

 

[Pascal]

What kind of gauge do you have ?

 

[workingonadream]

Pascal, im not sure. there is a small metal tube coming from my tank with a small diameter hose attached that goes to some sort of diaphragm in my lower cabinet. what I do know is that the light is only supposed to come on if the tank is 3/4 full.

 

[Nonchalant1]

Likely a rotted pumpout tube. The indicator, as you mentioned, is a pressure sensor on an air filled tube extending to the bottom of the tank. As the tank fills, black water starts to fill the tube from the bottom, increasing the captive air at the diaphragm until the pressure reaches the set amount to turn the light on. The rotted area of the pump out tube is always at the top, so air gets in and the tank is only pumped out an inch or two and fills back in very quickly. Changes in temperature can affect the pressure and the light switch.

On many boats, the top of the pumpout tube is a bronze right angle connector with a screw plug at the top, which you can take off to see into the big tube. If your's is like that, right after a pumpout look down into the tube to see how full the tank is.

 

[workingonadream]

thank you Nonchalant1, that is the same set up I have. I will remove the plug this weekend and inspect

 

[SEVEN]

My pick up tubes are all PVC and yet I have the same issue. The red light comes on, I pump out and the light stays on or comes on within days even though the tank is empty. It goes off sometimes days later. I’m going to replace the pressure switch/tube. I think it may have gotten clogged up.

 

[workingonadream]

Seven, I will see if I have the same issue as you, when I unscrew it. I would much rather it be the pressure switch

 

[Pascal]

Black water tank gauges are always unreliable. One way to tell is how long do you get stuff coming out.... i know it s hard to know the flow from a pump out but if you start sucking air within 30 seconds then you know it’s the pick up. On the other hand of it takes 5 or 10 minutes to pump out then you know it’s the gauge

Of course that’s assuming the tank is really full... if you don’t have a charcoal filter, fill it til it overflows

 

[workingonadream]

pascal, that is exactly my problem, I do not know what amount is in the tank. I was pumped out at the end of the season last year and the light came on rather soon into this season which perplexed me because I only use my bathrooms at night, I use the marinas during the day. once I remove the pressure tube, I will know better.

 

[edward]

Can you just stick the tank ?

 

[SKYCHENEY]

The original 3/4 full light had a 1/4" copper tube that extended down into the tank. That tube would rot off and the light would never come on or it would come on when the tank was full or nearly full.

The best solution is to scrap that old system and put in a Hart Tank Tender. It just uses a 1/8" plastic tube into the tank and it will give you readings accurate within just a few gallons.

 

[rwaldrop13]

The original 3/4 full light had a 1/4" copper tube that extended down into the tank. That tube would rot off and the light would never come on or it would come on when the tank was full or nearly full.

The best solution is to scrap that old system and put in a Hart Tank Tender. It just uses a 1/8" plastic tube into the tank and it will give you readings accurate within just a few gallons.

Alternatively, check the folks here. I haven't purchased a tank monitor yet, but they offer a pretty cost-effective setup. One of my marina neighbors just replaced his Hart with their system.

https://kus-usa.com/

 

[SKYCHENEY]

Alternatively, check the folks here. I haven't purchased a tank monitor yet, but they offer a pretty cost-effective setup. One of my marina neighbors just replaced his Hart with their system.

https://kus-usa.com/

I wouldn't do that. The Hart is simple and fool proof and won't ever corrode. Even stainless in an effluent tank is gonna corrode.

And the Hart is accurate to within a few gallons. No other system can do that.

 

[ian w]

On a 53 what does the breathe tube on the forward holding tank look like
I have difficulty pumping out and think the breather tube may be blocked
Can’t get to the breather on the hull

 

[drburke]

And the Hart is accurate to within a few gallons. No other system can do that.

Thanks for input, Sky. I wondered how accurate such a system would be, and it does sound preferable.

DAN

 

[CMeacham]

I'm looking at a Gobius Pro for this. One of the restrictions of this system is on fiberglass the wall thickness can't exceed 8mm (.315 inches)

Does anyone know the thickness of Hatteras holding tanks?

 

[cww]

I'm looking at a Gobius Pro for this. One of the restrictions of this system is on fiberglass the wall thickness can't exceed 8mm (.315 inches)Does anyone know the thickness of Hatteras holding tanks?

That’s basically a quarter inch you may be cutting it close with that tolerance.

 

[dar636]

I installed a Gobius system on my forward tank and it never worked.. I was hopeful and have tried moving the sensors around to different levels and locations but no joy. I still have the 3/4 indicator light which works but will probably switch to the Hart system and tie in the rest of the tanks.