Easiest Water Level Indicator

Introduction: Easiest Water Level Indicator

In day to day life storing water is one of the important task we have to do & with that we need to keep eye on that storage that the supply of water should be stopped when its reaches to its maximum level ,so this is best, cheapest & easiest circuit to do this task by just looking at LED indication from your working place to control strong of your water level.

Step 1: Required Components

Required Components List :-

1)IC - ULN2803 - 2 Pc.

2) 18 pin IC holder - 2 Pc.

3) Resistors
I) 10kohm - 10 Pc.
II) 560 ohm - 10 Pc.

4) LED's - Red,Yellow,Green,Blue - 3 Pc.
each ( You can choose by yourself according to your convenience for understanding the level of water )

5) Connecting wires - Rainbow wires 10 gauges ( length of the wire is depend that how long is your water storage from your indicator circuit )

6) Zero PCB or Dot matrix PCB

7) 12 V DC power supply.

8) Soldering Iron

9) Soldering wire

Step 2: Placement of IC Holder & IC

The placing of IC is very simple. Placing of IC is common for all type of IC's. When IC is placed in the circuit the notch of the IC is always should be on left side as shown in figure. The numbering of terminals of IC is starts from lower side of IC from left to right & then it continuous goes on from upper side of IC from right to left.
Refer the figure shown in picture for better understanding.

Step 3: Water Storage Circuit Connection

1) For indication of water storage level the IC has available of 8 levels as 8 terminal of IC.

2) Take out 8 resistors value of 10 k ohm from terminals 1 to 8 each & connect them to the water storage level.

3) Because resistors don't have any polarities ,so don't worry that which terminal have to connect where .

Refer the image for better understanding.

Step 4: Water Storage Indication Connection

1) As we connected 8 resistors of 10 k ohm value from terminal 1 to 8 for storage connection in previous step,for those storage connection we have corresponding indication output at just opposite to that of IC terminal of storage level, Ex. if water level is reached to level 5 then then indication will be shown on terminal 14 as output.

2) Corresponding level indication for output as given below

1 - 18
2 - 17
3 - 16
4 - 15
5 - 14
6 - 13
7 - 12
8 - 11

3) Take out 8 resistors value of 560 ohm from terminals 11 to 18 each.

4) Choose 8 LEDs of any colors you want to show indication of water level and connect their negative terminal to each of the 560 ohm resistors which is connected to IC from terminal 11 to 18 individually.

5) As negative terminals of all LEDs are connected to each 560 ohm resistor, positive terminal of all LEDs should be connected to positive terminal of 12 V DC power supply.

Step 5: Final Connection

1)Positive terminal of 12 V DC supply should be connected to terminal number 10 of IC & at the base of water storage.

2) Negative terminal of 12 V DC power supply should be connected to terminal number 9 of IC.

Refer image given for better understanding.

Step 6: Working of Water Level Indicator

Due to some reason I can't perform the work on Water level indicator on water storage , but I made similar adjustment which is similar as water level indicator.

I hope this project will be helpful to you for your personal water storage level indication.

1 Person Made This Project!


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Question 1 year ago on Step 2

The numbering of terminals of IC is starts from lower side of IC from left to right & then it continuous goes on from upper side of IC from right to left.
Refer the figure shown in picture for better understanding. The Picture shows 1 to 9 left to right, and then 10 to 18 left to right, which is inconsistent with the wording?


Question 4 years ago

Hi author, i made this.. it is working. but sometimes when i turn it on all the lights flickers... is this because of water resistance? an response would be appreciated.


Answer 4 years ago

First check all connections of your circuit, because of loose connection in circuit or in wire these types of errors can occurs.


Reply 4 years ago

That's what I thought at first, so took all the connections and dropped them on a glass of water. It works fine no flickering. When connected to my tank it works for first few seconds, then the flickering starts. Any idea?


Reply 2 years ago

might be the current.. enough voltage maybe because it needs to complete the circuit. have you come up with a solution? i'm thinking of building this


Tip 4 years ago on Step 6

To avoid your contact points from corrosion use stainless steels or other Non-corrosive metals. (Solder, Hot glue, heat shrink tubes)


7 years ago

If it doesn't work with water, as the title indicates, why publish it?


Reply 7 years ago

It does works with water but I couldn't show it with proper water storage due to some issues.I actually tried this in my college project but decide to make instructables after project . I am 100% sure that it'll definitely work with water.



Reply 6 years ago

that is actually abit confusing. I dont really understand what tecnical issue could prevent you from hanging two wires in a glassof water.

Anyway, the principle of having a Voltage on the waterand then having inputs at various levels is a tried and tested one. Usually a darlington is used then.

The ULN2803 is basically a set of inverters that as far as I understand, need a 1mA input (0.93mA to be correct). As you use 12 Volt and 10kohm resistors, it could work, if the water resistance is not too great.


Reply 4 years ago

hi i am having some problem with this project, i made it. It works fine in a small glass of water. But when i connect it to my tank the lights starts to flickers and slowly turns off. is this because of resistance? is there any way to resolve this?