water tank level indicator

Dave Angelini

Has anyone seen a simple method of roughly indicating (say 50%) the level of a water tank.
I do not want to put a hole in the tank or use a float switch. Something like that is used to indicate propane level on a 5 gallon barbecue tank.
Thanx!

inetdog

Theoretically you could use an ultrasound transducer to determine whether there was water or air opposite the sensor attached to the side of the tank at the right level.
The difference in thermal conductivity/thermal mass which is used for some propane tank sensors (pour hot water on the strip) is not going to do you any good through the walls of a poly tank.
How about some strain gauges under the tank to sense filled weight?
Just brainstorming a little.

If the tank is atmospheric rather than pressurized you could use a pressure sensor connected to the bottom of the tank. (There must be outlet piping somewhere, right?

westbranch

what about an old fashioned  vertical sight tube on the outside of the tank, before the pressure is raised or a float stick?

Wheelman55

Don't know what material your tanks are. We use the plastic 1,750 gallon tanks from Wylie. We get a pretty accurate measure from rapping on the sides of the tanks. There's also a screw on opening on the top that we can put a measuring stick in. 

Ralph Day

Dave, I use a multi led stud sensor to find the level of "fluid" in my camper's holding tanks.  Any stud sensor would likely work, and not too expensive or intrusive.

Ralph

Aguarancher

Most water tanks have a top and a bottom bulkhead fitting. Maybe others have said it, but just tee off the 2 fittings and use some 1” clear pvc pipe to make a sight line between the 2. You usually end up needing 1 pvc union to make up the plumbing. Only down side is if someone knocks off the standpipe, you have an empty tank. I have done this in many commercial applications with good results.

mike95490

I'm looking too.  Clear PVC and poly don't hold up outside in the UV.  And I've not found a pressure gauge that reads 0-5 psi (I actually need to read 65-75 psi in 1/2 psi increments, so I don't have to go up the hill to tap on the tank) I've got a float switch in it for the pump.
I use a siphon as a level gauge in my coolant tank for my generator, and it works well.

Aguarancher

If it’s a specific level you want to monitor, plumb as I stated previously, but with galv. pipe. Install a tee at the desired height and install a simple sight glass fitting or for remote viewing, a transducer. 1” sch 40 pvc is tougher than most think, even with uv exposure, at least that has been my personal experience.

Dave Angelini

Thank-you all ! I should have stated The application is for an elderly person who is not as mobile.They are 300 feet from the tank. I will go read these again and sleep on it. They just need to see 1/2 full

Here is the Aussie version but I am concerned the freaking Deer we have will cause an empty tank
http://www.amazon.com/gp/product/B00AUVXRUO?psc=1&redirect=true&ref_=ox_sc_act_title_3&smid=A3TR12UWMEK7IF

For my tanks I just feel the temp change when the sun is out. Water level is about 1 -2" above where you feel the change.

Aguarancher

  “Here is the Aussie version” simple and eloquent..looks like a winner, and a pair of binoculars for remote viewing

westbranch

this looks more deer proof... http://rainharvesting.com/product/tank-gauge/

Dave Angelini

Maybe this is OK but I really hate putting a hole in a 10 year-old tank. Thanks might be able to put the hole in the lid and make this work for indication only.hmmm. Last night there was a bear up the road and this does look pretty good for them also. Thank-you
this looks more deer proof... http://rainharvesting.com/product/tank-gauge/ 

sfttailpaul

I do not know the manufacturer of my tank's level apparatus but it is a rail that is mounted on the outside of the tank that has a sliding indicator which raises/lowers via a float (similiar to a toilet tank ball float) connected to SS cable which runs outside the tank, up/down attaching the indicator to the ball float. It is necessary to drill two small holes to screw it the rail (angle bracket) into the top of the tank (at the top of the man-hole). I used SS washers with rubber backing on the inside of the screw head. Haven't had a drop leak. Bottom of the rail is held to the tank via another angle iron with a stake driven into the ground, so no holes anywhere else.
I am actually working on a way to use the indicator for a switching method to turn my well pump on/off at specific gallon points. We MUST keep 3,500G for fire leaving me 600G to work with. I built a pressure system into my water supply also (avoiding cycling the well pump constantly) and that pump (separate) turns on/off with a simple pressure switch (55/30) but the current pressure switch for the well pump (additional & separate) turns on/off via a float switch at the inlet and is set at 50/30. I sure hope this is clear. Hard for me to describe stuff and noot get too redundant! IF someone needs, IO can find out who makes this gauge but it is simple enough to make from scratch. The rail looks like the type used for by-pass sliding doors; very light duty and the roller mechanism could easily have a metal plate attached to give a "sight" indicator at the point where the gallon markings are on the side of the tank.

zoneblue

Around these parts the tradition is a small hole in the roof of the tank, about 3/4 inch or so, a section of pipe, with a alluminium rod inside attached to a ball float on the bottom and a bright orange ball, or flag on the top. You can see those from quite a distance. Theres a bit of bracing above the lid to support the thing.

Dave Angelini

Pictures anyone?

Aguarancher

pics..
https://www.anadexlabs.com/shop/catalog/DipperDex-floating-pole-water-tank-level-indicator-p-7.html
https://www.anadexlabs.com/shop/catalog/DipperDex-Water-Level-Indicator-for-Fire-Storage-Tanks-Above-g-p-32.html

Mountain Don

We have a buried cistern. For the first half dozen years I used a dipstick through a fitting in the manhole extension lid. That became a pain after I built an insulated box over the manhole extension.  Since the cistern was already buried many options were not usable. So I went electronic. 

I have a drop-pipe inside the cistern with low voltage sensor to give me approx 7/8, 1/2 and 1/4 levels. Here's a photo of one of the sensor bolts.



 I used a length of CVPC pipe with a brass machine screw. I think the wire was underground low voltage sprinkler valve wire. One sensor at tube bottom. It is held vertical with a home made pvc bracket inside the cistern neck. The wires feed through a weather resistant compression fitting in the side of the neck, well above the water level. 

The circuit board was found on ebay, from a seller in Thailand. Something like US$6 or 7.  



Version 1 was mounted outside on the cistern neck box. Powered by a 9 volt battery. Weather proof bush button switch to see the level by green, amber or red LED. I used the momentary contact switch to avoid having a constant DC electrolysis current flowing through the cistern fittings. Also to save the battery. I used a battery as for V1 I did not want to have to run DC power from the cabin to the cistern.

 V2 is the same box but moved inside the cabin.  I thought it would be handier that way. Plus I was digging a trench for something else so had the opportunity to run some wire for it.  V3 will have the 9 volt battery supplanted with a 24 VDC to 9 VDC buck converter, also found on ebay for a couple of dollars. 



Pardon the poor image quality.

zoneblue

Kiwi ones as often home made, but heres a commerical verison:
http://www.maclon.co.nz/trough-valves/water-level-indictor

Johann

Dave Angelini said:

Has anyone seen a simple method of roughly indicating (say 50%) the level of a water tank.
I do not want to put a hole in the tank or use a float switch. Something like that is used to indicate propane level on a 5 gallon barbecue tank.
Thanx!

If a water line comes into the home from the tank. Then a pressure gauge is all that is needed. Just hook a gauge up to the waterline inside there home. The higher the water level is the higher the pressure.

Dave Angelini

The water line does not come in the home from the tank. But good suggestion for someone else here.

levsmith

Mountain Don said:

We have a buried cistern. For the first half dozen years I used a dipstick through a fitting in the manhole extension lid. That became a pain after I built an insulated box over the manhole extension.  Since the cistern was already buried many options were not usable. So I went electronic. 

I have a drop-pipe inside the cistern with low voltage sensor to give me approx 7/8, 1/2 and 1/4 levels. Here's a photo of one of the sensor bolts.



 I used a length of CVPC pipe with a brass machine screw. I think the wire was underground low voltage sprinkler valve wire. One sensor at tube bottom. It is held vertical with a home made pvc bracket inside the cistern neck. The wires feed through a weather resistant compression fitting in the side of the neck, well above the water level. 

The circuit board was found on ebay, from a seller in Thailand. Something like US$6 or 7.  



Version 1 was mounted outside on the cistern neck box. Powered by a 9 volt battery. Weather proof bush button switch to see the level by green, amber or red LED. I used the momentary contact switch to avoid having a constant DC electrolysis current flowing through the cistern fittings. Also to save the battery. I used a battery as for V1 I did not want to have to run DC power from the cabin to the cistern.

 V2 is the same box but moved inside the cabin.  I thought it would be handier that way. Plus I was digging a trench for something else so had the opportunity to run some wire for it.  V3 will have the 9 volt battery supplanted with a 24 VDC to 9 VDC buck converter, also found on ebay for a couple of dollars. 



Pardon the poor image quality.

I saw something like this on mother earth news but it looked like a very old arcticle with terrible quality pictures. Did you find instructions for this somewhere else? I would like to make one but would like 8 to 10 LED lights to give a little more accurate reading. I have found a video on youtube showing how to build the circuit board but have heard that if the sensor is built like yours, the copper could corrode if it is in contact with the water. I would like to see how you built and wired yours!

grantiago

I ran a nylon string through the hole for the water inlet on the top edge of my tank. To keep it from fouling and reduce the friction it runs through a small piece of pvc pipe -- glued in place to one side. On the inside of the tank, I tied a half-liter plastic soda bottle half-filled with water. On the outside, I tied a 4x4 cm piece tubular steel to the string. I painted the steel white. My tank is black. With the tank full, I adjusted the knot so the steel is near ground level.

The tank is apx 70 mtrs from the house and about 10 mts up through some trees. No problem seeing it from the bath window. In all about 15 minutes to install. Zero cost, zero maintenance other than I had to replace the string.  Five years running.

Mountain Don

levsmith said:

Did you find instructions for this somewhere else? I would like to make one but would like 8 to 10 LED lights to give a little more accurate reading. I have found a video on youtube showing how to build the circuit board but have heard that if the sensor is built like yours, the copper could corrode if it is in contact with Mine just came out of my mind anthe water. ......

The idea sprang from my mind and as it was not an original thought the parts came from ebay.   I did find plans that could be readily adapted to indicate more levels.  For me, having a half full and a 1/4 left indication would be sufficient.

I believe the biggest issue with the electrical contacts in water would be from electrolysis if the power is left on all the time. That is why the cistern level indicator uses a momentary contact switch. I also found plans someplace for a unit that used low voltage AC instead of DC.  The readily available boards are so inexpensive I took that easy route. 

I can answer any specific questions. Mine was pretty much off the shelf parts.  The drop pipe/rod for the electrical contacts was the only part that took a lot of thought. Because the cistern was already buried through the tank wall solutions were not available.   There are some non penetrating solutions available in the RV industry. Some kind of sensing material on the exterior. 

inetdog

I can think of two possible ways of determining the level from the outside without penetrations in addition to the sonar transducer I mentioned earlier:
1. A thermal sensor that applied heat to the outside wall of the tank and measured the temperature rise. The rise will be far lower if that part of the tank wall is below the liquid level. You have to use temp difference for the measurement because the water and air temperatures will vary independently of the level.
2. An electrical detector similar to (but not identical to) a stud finder that senses the mass of water on the other side of the tank wall.

vtmaps

inetdog said:

I can think of two possible ways of determining the level from the outside without penetrations in addition to the sonar transducer I mentioned earlier:

I believe there are sensors that work by capacitance.  Of course, they do not work on metal tanks.

--vtMaps

Dave Angelini

grantiago said:

I ran a nylon string through the hole for the water inlet on the top edge of my tank. To keep it from fouling and reduce the friction it runs through a small piece of pvc pipe -- glued in place to one side. On the inside of the tank, I tied a half-liter plastic soda bottle half-filled with water. On the outside, I tied a 4x4 cm piece tubular steel to the string. I painted the steel white. My tank is black. With the tank full, I adjusted the knot so the steel is near ground level.

The tank is apx 70 mtrs from the house and about 10 mts up through some trees. No problem seeing it from the bath window. In all about 15 minutes to install. Zero cost, zero maintenance other than I had to replace the string.  Five years running.

I would like a picture of this but I do get it.  Seems like the best one here for my application.  Thank-you!  --Dave

just starting

If it is above ground Tie a brick on a rope about a foot away tia a one gallon bottle on the otherside tie a lighter weight brick the rope has to be about two feet longer then the tank is tall put the bottle side in the tank it will float up and down with the water level the higher the brick the lower the water same as last post just a little different used this while core drilling

Dave Angelini

How is it different please?

Mangas

We use a short pvc sleeve through the plastic tank lid and run a brass rod through to a pan float. The pvc sleeve is slightly larger than the brass rod.

At the top of the rod thread a relector with a stop beneath it to prevent the rod from dropping through the lid. The sleeved rod and float will slide up and down through the lid.  Measure the rod and float to set the right length.

We install the rod 20 percent shorter than the tank depth, lower pvc length and manhole cover/lid to assure the tank is never more than 80 percent empty.

The pvc pipe keeps the rod generally straight against the water pressure when filling.   There are more expensive ways to do it but this simple set up works for me.

just starting

If you only use water the jug has to be heavier than the pipe can get hung up and any ice build up can hold the jug used bricks for more weight

Dave Angelini

Ice, ok I get it thank-you. It is rare here but it does happen.