Holding tank sensor

General
1

We have tried a couple of non-contact holding tank sensors. Last week there was a little chocolate fountain when opening the pump out deck fitting, the gauge said not full. It was.

What about float type sensors, those made for holding tanks? I heard that they can jam. Does anyone have experience with float type transducers?

2

Hi Alan,

We lived aboard a Tartan 40 (SS Design) for seven years.

 It cane with a float sensor  
     (failed first year and was god awful to clean up)
 Switched to a non contact float 
     ( Ditto)
 Switched to a radar distance sensor 
     ( failed first week)
 THAN
 Installed an air pressure system (Tank Tender)
 No electricity
 Totally mechanical and self contained
 Wonderfully easy to install
 The tank only requires a #10-32 tap in top over the deepest section
      This accepts a slender ridged tube 
      you cut to be a bitt short of the bottom
      You put the small remote control panel where ever you like
      You connect one tube from the panel to the slender tube
Unit is available to check any number of tanks
      Water
      Fuel
      Waste  (Waste is totally isolated from the others)
               BUT
             (Shares the same control panel)
Company owner answers phone and will help in all things

      Accuracy was unbelievable

When the slender tube does get plugged 
     (You just knew that would happen)
It is obvious at the panel that the tube is plugged
Just disconnect tube 
     (quick fitting)
Unscrew 10-32 fitting
Disconnect slender tube
     pipe cleaner it out
A 5 minute job at longest
     The hole is so small almost no smell escapes
Reassemble 
   (I kept a spare tube and change was done in less than a minute)

https://tanktender.com/

https://citimarinestore.com/en/boat-cleaning-supplies/5806-tank-tender-precision-tank-measuring-system.html

Fran Cichowski     904 772 4712     captfran1@gmail.com
     Southpaw  N30U
     Noank, CT
3

Alan, it’s more helpful if you tell us what boat you have, plus your location, INA being an international organization.

I’m in Canada with a 1987 NS30U. I installed a Tech Edge (www.tankedge.com) tank monitor on holding tank and two water tanks. The tank sensors use a foil tape attached to it the exterior of the tank. Fairly easy to install, and no need to drill a hole in tanks, especially the holding tank. Can monitor 3 tanks, you can calibrate it for the wedge shaped tanks. If you are in USA, order directly from manufacturer located in Oregon. In Canada, I bought mine from Marine Outfitters in Ontario.

Cheers, Don

4

I installed a Garnet SeeLevel system. It is made in Calgary Alberta but it was cheaper to buy it from a retailer in Texas. The manufacturer has a deal with venders that it won’t sell below a certain price which explains the anomaly. Like Don’s system it uses two foil strips to m a sure the level of the tank contents and it can monitor 3 tanks. Unlike Don’s it can’t be calibrated to account for tapered tanks. I suspect the two foil system is what you refer to as no contact systems. My monitor works great on the water tank and worked fine on the holding tank when the tank was new. Over time the holding tank developed scale on the inside walls from the interaction between urine and salt water used for flushing. The tank now permanently reads full even after a pump out. At least I don’t have a Willy Wanka Chocolate fountain.

Practical Sailor did a number of tests on tank monitors a number of years ago. You should be able to find the results on line. The Tank Tender was ranked first if I remember correctly. It uses air pressure to measure the height of the fluid in the tank. Also many years ago Practical Boat Owner had an article covering the conversion of a heart rate monitor to a holding tank monitor. It relied upon the same principle as the Tank Tender.

Mark Powers

La Reina 26C, Vancouver B.C.

5

Thanks for the info, I will check out both suggestions. Today I coerced the gauge into working but I don’t hold much hope long term. What confused matters is that the meter on the potable water was sticking, have to flick it to move. The water and holding tank systems are wired together and both acted up simultaneously for different reasons, other than just being a boat.

Sorry about the anonymity, forgot.

Alan & Tracy, NS30C “Corvus” #216, BPYC Toronto

6

I built a “Tank Tender” style system to monitor levels for 3 of the tanks on my boat. It has worked well for the past two years. No moving parts in tank and no power consumption. I added the ability to clear the dip tube if plugged without removal. Quite happy with the install and would recommend a “Tank Tender” style system.

Blake & Helen “Procyon” N33 Vancouver BC