Alarm or meter for freshwater tank?

[rwsandersii]

Hey everyone.

I'm tired of ripping apart my V-berth everytime we fill the water tank to monitor the water level. The first few times we filled, the cap for the tank leaked a bit on our cushions, so since then I've opened everything up and watched the level and stopped a few inches from the top. 

I'm considering installing a float switch wired to an on/off switch with a buzzer:
https://www.amazon.com/dp/B00HGAIXX8/?coliid=I3VIADB1VSDB0O&colid=31VQMGLTSAIC1&psc=1&ref_=lv_ov_lig_dp_it
It would require drilling through the wood and then fiberglass of the tank. 

I'm wondering what might go wrong, so I thought I'd ask if anyone else has tried this.

Thanks,
Richard
Compac 27/3 Of Beren and Luthien
and former caregiver of Compac 23/3 Thunderchild

[wes]

I went the electronic route and installed a Maretron TLM-100 ultrasonic sensor. It reports tank level on the NMEA 2000 data bus, so it can be displayed on any chart plotter or multi-function display with NMEA 2000 capability. I also have a Maretron sensor on my fuel tank (it's designed to fit in the same standard opening as a mechanical sensor), and when I replace my waste tank I'll install one there too.

Some may say this is a lot of tech for a CP 27! But it's fun for me and you can't beat having this info displayable in the cockpit; no crawling around in the engine room or v-berth.

One caution about mechanical sensors is that the water tank is anything but rectangular, so the displayed level willl be very inaccurate. The Maretron sensor can be calibrated to read accurately in a tank of any shape.

Wes

[deisher6]

Hey Richard:  I had to smile when I read our post.  I cannot recall how many times that I have run the water tank over on our CP-27s, even a couple of times on our PSC-34.  It is a messy way to start a cruise.

Wes's solution is both elegant and pretty cool.  I have admired all his upgrades on Sophie, especially the fuel gauge. It is so much better than sticking your head in the starboard locker with a light trying to read the mechanical gauge.  They are a great upgrade especially if you are going to keep and use your ComPac.

After stating that, I will admit that it was an upgrade that I never got around to on our last CP-27.  And on our PSC-34 I still pull up the sole to check the fuel, in spite of a mechanical to electrical repeater by the nav table.  Even after overflowing the water tanks a couple of times (I did not realize that with bow and stern water tanks on line that the aft tank would fill when filling the bow tank, the bow tank is higher).  Now I lamely rely on isolating the tanks, making sure that the inspection ports are secure and keeping an eye on the tank vents to see when they are full.  That works nearly all the time.

regards charlie

[rwsandersii]

Wes,
Thanks for the input.  Sadly my electronics are way behind and I don't believe my chartplotter is NMEA compatible.  Everything is from 2010 when I bought the boat. 
I don't really need to know the level, I've learned to gauge that by the waterline and  by just a feel for how much we use over time.  I really just need a beep or buzz to stop before an overflow. 
That said, I like the meter you used and I'm wondering where you installed it?  Did you attach it to the cap?  How did you run wires to it under the cushions?
Charlie,
No fuel tank.  I was able to talk Gerry and Rich into installing an SolidNav electric motor.  We love it, but monitoring a battery bank for this purpose is a complex issue and it appears I destroyed 4 AGMs.  I'm hoping to upgrade to some LiFePO4 soon.  Any battery experts in this forum?
Thanks,
Richard
Compac 27/3 Of Beren and Luthien
former caregiver of Compac 23/3 Thunderchild

[crazycarl]

I don't have a 27, but our Seidelman has an overflow for the water tank.  I fill the water intake until I hear it splashing overboard, then i know it's full.  Of course, it doesn't indicate how much water is in the tank after use.

[kevin27]

https://www.amazon.com/Savant-Digital-Meter-Water-Filter/dp/B09PFPCYV9

DigiFlow 8300T

I have a bladder in the tank area so nothing else can work. You reset this to zero and program the tank capacity. And you can have a threshold like 10 gal where it alarms, telling you are close to empty. Had a lot of trouble finding it and paid more like $125 for it, but it works and is easy/cheap to get now. Reads in whole gallons, no decimal place.