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-   -   Holding tank monitoring options? (https://www.cruisersforum.com/forums/f115/holding-tank-monitoring-options-181279.html)

Kim Gregory 29-03-2017 15:16

Re: Holding tank monitoring options?
 
Most holding tanks have the 1.5 inch pump out hose reaching to the bottom of the tank.
As the tank fills, each inch of this hose holds 1.76 cubic inches of water.
1 cubic foot of water weighs 62 lbs, so this 1 inch of water weighs 0.063 lbs.
To push that 1 inch of water down the hose, you need 0.036 lb / sq inch air pressure. ( 0.063 lbs / 1.76 square inches, the surface area if the hose ).
To push the water down a foot, you need 0.43 lb / sq inch (0.036 x 12 ) of air pressure.

( picture putting a styrofoam plug in the hose, and weighing it down with 3/4 lb of ball bearings )

Adapt a spare screw cap for your deck fitting, and add a low pressure gauge, and a tire valve. Pump air into the tightly sealed cap ( bicycle pump), and the air will push the water down the hose. When the air pressure is high enough, all the water is pushed out of the hose.

Read the air pressure gauge. If your tank is 24 inches deep, and the gauge says 0.8 lbs, then your tank is full.
https://sites.google.com/site/dougla...eckFitting.jpg
Can anyone verify my math on this?
- Kim

Dave22q 29-03-2017 15:46

Re: Holding tank monitoring options?
 
I do wish the monitor was sealed but it is what it is. If I was really bothered i would seal it with one of many commercial products. Early on I had some issues and Dennis solved them. True, sometimes you need to reset the full and empty readouts but it's easy. Over 18 months in place and I'm still a satisfied customer.
Anybody can cry 'enough' if a customer keeps whining and that may be what happened here.

Bill O 29-03-2017 16:47

Re: Holding tank monitoring options?
 
We have an aluminum holding tank (yes, it's not ideal) and we purchased the Solo System from Dennis (SCAD type w/PVC tube insert made for metal tanks). We are on the third probe and for whatever reason they just stop working. Dennis has been nice enough to test and replace them for free, but unfortunately the product doesn't work for us. Dennis is a nice guy and I hate to keep sending them back, and since he can't figure out what's going on, we'll try something else.

Several years ago we replaced our fuel and water senders with WEMA senders/gauges and have had no problems/been very happy with them. So whenever they have a sale, we'll be switching out.

Bill O.

peghall 29-03-2017 19:17

Re: Holding tank monitoring options?
 
There are discussions about several tank monitoring systems in this thread...I think you've dropped information about the Tank Tender into the middle of some discussion about the Profile/SCAD system.

Dockhead 30-03-2017 06:27

Re: Holding tank monitoring options?
 
Quote:

Originally Posted by Bill O (Post 2359388)
We have an aluminum holding tank (yes, it's not ideal) and we purchased the Solo System from Dennis (SCAD type w/PVC tube insert made for metal tanks). We are on the third probe and for whatever reason they just stop working. Dennis has been nice enough to test and replace them for free, but unfortunately the product doesn't work for us. Dennis is a nice guy and I hate to keep sending them back, and since he can't figure out what's going on, we'll try something else.

Several years ago we replaced our fuel and water senders with WEMA senders/gauges and have had no problems/been very happy with them. So whenever they have a sale, we'll be switching out.

Bill O.

My boat was delivered new in 2001 with WEMA sensors and gauges. Fuel still working fine. Water replaced one sensor six years ago. Black water second sensor failed a couple of years ago, when I switched to Maretron ultrasonic.

I would rate WEMA as "OK, but not great." The premium solution is Tank Tender, IMHO. Maretron - can't say yet how good it is, but so far no problems.

Bill O 30-03-2017 06:45

Re: Holding tank monitoring options?
 
Dockhead,
The Maretron Ultrasonic is interesting. How long has it been in? Since I haven't switched to the WEMA yet it may be an option. Anyone have a track record on one for the holding tank?

Which WEMA sensor did you have? They've changed them a bit and it appears they may have changed the SHS sensor since 2001. Did yours have an external float?

Bill O.

Dockhead 31-03-2017 01:30

Re: Holding tank monitoring options?
 
Quote:

Originally Posted by Bill O (Post 2359798)
Dockhead,
The Maretron Ultrasonic is interesting. How long has it been in? Since I haven't switched to the WEMA yet it may be an option. Anyone have a track record on one for the holding tank?

Which WEMA sensor did you have? They've changed them a bit and it appears they may have changed the SHS sensor since 2001. Did yours have an external float?

Bill O.

Maretron one year. So far so good. Big advantage over WEMA is it shows exactly the level. WEMA just shows low, high, and fuel (IIRC).

SaltyMetals 04-04-2017 13:14

Re: Holding tank monitoring options?
 
I need a gauge but absolutely do not like the idea of drilling holes in my holding tank when there is another solution. I just ordered a Gobius kit (Swedish) which apparently is well-loved by the Scandinavians. It is based on three sensors attached on the OUTSIDE of the holding tank. I will report back on this thread once i have it installed and working.

Yes i know it only shows 1/4, then 1/2, then 3/4, but who needs to know very precisely whether it is 7/8ths or 15/16ths full?
Andrew

a64pilot 04-04-2017 14:26

Holding tank monitoring options?
 
I have a SCAD, yet to install. It is indeed an open circuit board.
Maybe I'll conformal coat the board first, real easy to do.
Many sources, this is just one, either spray it on or brush it on, let it dry, your done
https://www.amazon.com/MG-Chemicals-...formal+coating

Kelkara 12-05-2017 12:59

Re: Holding tank monitoring options?
 
2 Attachment(s)
I thought I'd follow up on this thread.

As a temporary measure I've decided to go with the suggestion of a home-built pneumatic monitor made from a blood-pressure gauge fed down the deck pump-out fitting.

I calibrated it by counting pumps from the manual head going into an empty tank. The test run with clean sea-water worked really well.

I'll just have to see how well it performs in the wild ... or whether I will be convinced to splash out on the tank-tender.

captstu 12-05-2017 14:07

Re: Holding tank monitoring options?
 
Good plan.

I've installed three SCAD/SOLO and two Tank-Edge Smart Mini holding tank monitors.

None worked.

There is no chance they could ever work in my boat's environment.

the SCAD/SOLO has a mild brass momentary contact switch that turned green and failed within two weeks. They refused to honor the warranty saying, it turns out reasonably, that the environment caused the failure, not their design. They did, however, sell me a second and eventually a third (Remember, insanity is doing the same thing over and over and expecting a different outcome.)

I went to the web and found Tank-Edge. I am now on my second tank edge - it reads empty when empty and 1/2 full when full - and won't calibrate. The first one worked sort of for a day and failed. They charged me about $110 for the first one and $160 for the second - but did say they will refund part of the second fee when I return the parts.

Turns out, this time the foil I placed on the tank dissolved into foil dust - that may have been the only problem.

These things are junk. They work in a clean, dry, stable, no-vibration environment - but have no chance in the real world.

Still looking for a brand that works. These two aren't it.

Or, I could get an air head or a porta-potti

Kenomac 12-05-2017 15:08

Re: Holding tank monitoring options?
 
1 Attachment(s)
Figure out how much water per flush, put a notepad next to the head, then write down a hashmark each time you go.

wsmurdoch 12-05-2017 15:33

Re: Holding tank monitoring options?
 
Quote:

Originally Posted by Kenomac (Post 2391773)
Figure out how much water per flush, put a notepad next to the head, then write down a hashmark each time you go.

Then automate it.
https://images-na.ssl-images-amazon....L._SL1001_.jpg

https://smile.amazon.com/GOGO-Resett...ulling+counter

ottow 15-05-2017 05:38

Re: Holding tank monitoring options?
 
To solve a identical issue I installed a Gardena Hose Fittings Water Smart Flow Meter on the inlet.
It gives me a decent idea how full the tank is, with a 40L tank I know that when reads ~30L it is time for a pump-out.

Cheers,

Otto

SaltyMetals 25-05-2017 12:11

Re: Holding tank monitoring options?
 
Just installed my Gobius. No holes to drill in the tank (which might then leak/smell and no pressure tube sensor that might be susceptible to clogging. I find Gobius to be a very elegant solution. The only thing you then see is a control/ display unit the size and thickness of a credit card. If I am not having to use the holding tank I can switch it off at the control/display. Wonderful solution.

yvest 03-05-2019 00:39

Re: Holding tank monitoring options?
 
Quote:

Originally Posted by SaltyMetals (Post 2400318)
Just installed my Gobius. No holes to drill in the tank (which might then leak/smell and no pressure tube sensor that might be susceptible to clogging. I find Gobius to be a very elegant solution. The only thing you then see is a control/ display unit the size and thickness of a credit card. If I am not having to use the holding tank I can switch it off at the control/display. Wonderful solution.

Thanks a lot for the info, is it still working fine ?

SaltyMetals 03-05-2019 16:34

Re: Holding tank monitoring options?
 
Yvest,
Yes my Gobius is all working fine. I had a problem after about 3 mths and Gobius sent me a new part (no charge). But it is truly a very elegant solution to knowing the level in the holding tank. Seems to be v popular in Scandinavia (Gobius is Swedish). i wonder what people do if their boat has no indicator. Just wait until it overflows?
Yuck !
Andrew
"Genial Bee"

olewsaa 11-05-2019 11:46

Re: Holding tank monitoring options?
 
My yacht is an Ovni with aluminum holding tank and the walls are relatively thick. The Gobius state the the limit is 5 mm Al. This is about the how thick the walls are. Not so easy to measure.

Do someone have experience with Gobius onboard Ovnis ?

I started of with simpler sensors, they work fine for thinner walls of plastic and some more advanced also metal, tested with bucket etc. But they all fail at the tick Al walls in the Ovni holding tank.

Ole

SaltyMetals 14-05-2019 03:42

Re: Holding tank monitoring options?
 
Ole, I suggest you call the Tech Services of Gobius directly since a distributor is unlikely to have accurate advice on this. I found their Tech services very good and pro-active.
andrew
"Genial Bee"

two-rocks 16-05-2019 11:24

Re: Holding tank monitoring options?
 
Put a gobius in this year - have yet to tell if it's full as we haven't filled it yet ;-)

It uses 'sound' - but not ultrasound. You can hear it when it checks the tank level - but can set how often you want it to check. I set it to never, and just manually 'ping' to check. It sounds like faint white noise for about 1/2 a second. Prefer not to hear that while sleeping.

Prior to this we had nothing to indicate tank level, a real $hit show as the holding tank vent is on deck ;-)

Did NOT want the stick on kind discussed in this thread. Have owned many RV's with them and I'll pass.

SaltyMetals 27-05-2019 07:17

Re: Holding tank monitoring options?
 
Quote:

Originally Posted by two-rocks (Post 2890150)
Put a gobius in this year - have yet to tell if it's full as we haven't filled it yet ;-)

It uses 'sound' - but not ultrasound. You can hear it when it checks the tank level - but can set how often you want it to check. I set it to never, and just manually 'ping' to check. It sounds like faint white noise for about 1/2 a second. Prefer not to hear that while sleeping.

Prior to this we had nothing to indicate tank level, a real $hit show as the holding tank vent is on deck ;-)

Did NOT want the stick on kind discussed in this thread. Have owned many RV's with them and I'll pass.

Hv been using Gobius for 2 yrs now. Recommended to me by a Scandinavian. Gobius is Swedish.
Wonderful bit of kit. I cant imagine how people manag their holding tanks without it. If you hv nothing then at some point the tank will overflow, block the breather and makes lots of unwelcome smell. If you use a system that requires drilling holes in yr tank then sooner or later you will get the unwelcome smells anyway.
Gobius? IMHO, best thing since sliced bread.

zboss 27-07-2020 15:56

Re: Holding tank monitoring options?
 
It sounds like the gobius only tells you if the tank is full or not - it does not tell you how full the tank is.

SaltyMetals 27-07-2020 16:14

Re: Holding tank monitoring options?
 
No, you are given three sensors. Idea being 25% , 50% , and 75% but you can decide where you put them. It is done w a 3M adhesive so once you hv stuck the sensor on that is it. No change poss. If I were to be doing it again I wld rather put the top one at 80 or 90% but what I hv works well. I know that once it reaches 75% there is only about 4-5 more uses left. Great system.

Howler 13-09-2020 09:22

Re: Holding tank monitoring options?
 
Quote:

Originally Posted by SaltyMetals (Post 2344337)
Peg, i think you are the recognised guru when it comes to this subject ( I have read some of your stuff before elsewhere). I need a unit (plastic holding tank in a Jeanneau 43ds) and like the idea of the Gobius (Tankmätare för båt och fritidshus) which requires no holes in the tank with the sensors being attached on the outside. As posted by OttowW yesterday. You have not commented on this unit so far. Nobody else seems to have commented on this unit either.

do any of you guys out there have experience of the Gobius?

There've already been a few replies but I'll add the following as I just installed a Gobius Pro on a plastic holding tank in a Beneteau 41.1. I set it at a height corresponding to about 2/3 full, but that's a user choice. Also, if you're willing to buy more sensors, you can line them up vertically to have a more granular view. Several commented on exterior sensors being misled by buildup on the interior of the tank wall. I don't believe this will be a problem with the Gobius Pro because it sends and reads back a vibration signature, influenced by the hollowness of the tank vs. detecting what's immediately behind the wall like some of the other technologies.

You can optionally monitor the sensor with an included red/green LED that you wire to the sensor, via Bluetooth to your smartphone, or by connection to other third party monitors.

I tested the sensor by filling an empty tank with a hose through the pumpout port on deck. The sensor reacted as it should when the fluid level reached it. So far so good with the dockside test. But the first field test on a cruise wasn't achieved because the sensor detached and fell off! In spite of following the installation instructions, the adhesive just wouldn't hold.

In an earlier thread, someone suggested using acetone to remove the waxy substance often found on plastic tanks. I'll try that next. An extra two-sided adhesive pad is included in the box. Does anyone have further suggestions on how to achieve the best adhesion?

Anyway, preliminary conclusion is it's a perfect fit for your need, not too expensive and easy to install. I even operate it off of a portable 12V rechargeable LION battery pack. I didn't want to wire it into the boat until fully tested. That works fine. It only sips milli-amps in standby mode, and consumes a few more when it actually senses, but you set the frequency you want and it only takes a few seconds each time.

One suggestion... if you use the provided LED monitor, use male/female connectors that can be plugged and unplugged. On the sensor, put a male on the green lead and a female on the yellow lead and the opposite on the corresponding leads on the LED monitor. The reason for this is there's a documented hack needed if the device is locked to your smartphone and you need to reinstall the app whereby you disconnect the LED monitor, and "short circuit" the leads from the sensor. That's explained here.

SaltyMetals 13-09-2020 09:46

Re: Holding tank monitoring options?
 
I installed a Gobius sensor on the stinless steel holding tank in my Jeanneau 43ds. About 4 yrs ago. Works like a charm.


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