Water Level Basics: How to make and use one

Water levels are a great way to find a level spot on items like posts or stakes, so you can build structures that are even and correct. The simple construction and easy setup make a water level a popular tool to have on-hand for a variety of projects.

Making a water level is easy with a few household items like tubing and water. You can then use the water level as needed so you have a level, even structure, or item every time.

What is Water Level?

A water level is any device utilizing the surface of liquid water to establish a local horizontal plane of reference; used to determine the apparent inclination of an object or surface and for matching elevations of locations that are too far apart for a spirit level to span.

Water level, also known as gauge height or stage, is the elevation of the free surface of a sea, stream, lake, or reservoir relative to a specified vertical datum.

The simplest water level is a section of clear tubing, partially filled with water. Water is easily procured for use and easily discarded after use. The ends are held vertical, and the rest of the tubing lies on the ground or floor.

The water level at each end of the tube will be at the same elevation, whether the two ends are adjacent or far apart. Water levels have been used for many years. The water level is lower-tech than the laser level, but it can be more accurate over long distances and works without a sightline, such as around corners.

To avoid error, all of the water should be at the same temperature. Other sources of error include difficulty reading due to meniscus.

If the water level is used often, the dye can be added to the water to make it easier to see. If the water level is used outdoors in winter, antifreeze can be added to the water. Automotive window washer fluid can also be used for antifreeze and increased visibility.

Additionally, it inhibits the formation of error-causing bubbles. A surfactant (surface active agent), such as hand-dishwashing liquid detergent, can be added to the water to significantly lower the surface tension of the water.

This liquid solution will flow more easily and more rapidly in the tube than plain water, so the operation of the device will be more precise, repeatable, and responsive – particularly when using a small-diameter tube. Also, this liquid solution can be emptied from a small-diameter tube more easily than plain water.

How To Make a Homemade Water Level?

A water level is easy and inexpensive to make, making it perfect for leveling a deck or shed foundation and more accurate than a carpenter’s level over long distances. A water level can also be used around corners that are out of the line of sight, something a laser or builder’s level can’t do.

A water-level works on the principle that a liquid always seeks its own level, it doesn’t matter if the body of water is a bathtub or a lake.

As long as there are no outside influences at work (such as the wind or tides), the water at one end of the body of water is the same height as the water at the other end. A water-level simply substitutes a plastic tube for the body of water.

Here’s how to make your own water level using nothing more than a length of flexible, plastic tubing (available by the foot at home centers in the plumbing department) and two stakes or dowels. We used 3/8″ I.D. tubing for our water, but sizes of 1/4″ I.D. or larger will work as well.

To make a water level:

  • Drive a stake or dowel in the ground near the middle of the foundation.
  • Attach one end of a piece of flexible tubing to the stake with the open end of the tube higher than the desired top of the foundation blocks.
  • Mix a little red food coloring to tap water in a container to make it easier to see the water level.
  • Hold the other end of the tube at the same height as the attached end, and fill the tube with water until it’s a couple of inches below the ends of the tube. Check to make sure there are no air bubbles in the tube.
  • Hold your thumb firmly over the unattached end of the tube, and move the tube over to one of the foundation blocks.
  • Stand a stake or dowel vertically on top of the foundation, and hold the tube against it with both ends of the tube at about the same height.
  • Release your thumb from the open end of the tube, making sure water doesn’t come out of either end of the tube. Adjust the height of the tube so you have the about the same amount of tubing above the water at both ends.
  • Mark the height of the water level in the tube on the stake or dowel.
  • Place you thumb over the open end of the tube, and move to the next foundation block. If the foundation is level, the water in the tube will be at the same height as the mark on the stake or dowel.
  • If the mark is higher than the water level in the tube, lower the block until the mark and water level align. If the mark is lower than the water level in the tube, raise the block by that amount to level the foundation.
  • If at any point water spills out of the tube, refill the tube and start over on all the measurements.

How to Use a Water Level?

Step-1. Bring the water level to the items you want to measure. The water level is often used to determine the level spot on 2 items that are at a distance from each other, such as posts or stakes in the ground. Make sure the items are in the ground or set up on a clamp attached to a work table so they are stable and firm. You can also use the water level for construction projects where you need to find 2 level areas on different items that are close to one another.

Water levels are a great way to find a level spot on items like posts or stakes, so you can build structures that are even and correct.

Step-2. Hold 1 end of the level against 1 of the posts. Make sure the open end faces upward. Place 2 nails on either side of the end of the tube to keep it in place. The nails should be just wide enough to catch the tube but not pinch it. You can also use a clamp on the top of the end of the tube if you do not want to put holes in the post or if the item is not made of wood and cannot be nailed into.

Step-3. Place the other end of the level against the other post. Keep your thumb over the open end of the tube so no water splashes out. Then, stand back and see where the water sits at either end of the tube. Notice if the water appears higher or lower in 1 end. This means the spots are not level and you need to adjust where the level sits on the posts so the water levels match.

Step-4. Slide the free end of the tube up or down until the level on both ends matches. Continue to check the levels as you slide the free end of the tube. The water should settle so that it hits the same level on both ends of the tube. If you are leveling items that are more than an arm’s distance away from each other, you may need someone to hold the free end of the tube and move it for you so you can ensure the water levels are correct on both ends.

Step-5. Mark the items at the level spot. Once the meniscus, or water line, is level on both ends of the tube, use chalk or a pencil to mark the spot on both posts or items. You can then release the attached end of the tube and use the water level on a different area, setting it up again with nails or a clamp.

How to Maintaining the Water Level?

  • Make sure there are no kinks or knots in the tubing. Kinks and knots can throw off the level and result in an incorrect reading. Slide your hand over the entire length of the tube before you use it so you can be sure there are no kinks or knots. A tube that is old or worn may be more prone to knots and kinks so you may want to replace it over time.
  • Empty the water level after each use to prevent air bubbles. Leaving water in the tube for a long period of time can allow air bubbles to form, which can then throw off the water levels in the tube. You should also empty and refill the water level before you use it to ensure the measurements are correct.
  • Keep the water level in a shaded, cool spot to prevent liquid expansion. Exposure to heat and direct sunlight can cause the tube to get too hot, causing the liquid to expand once it touches the tube. This can then throw off your water levels and result in an incorrect reading. Store the tube for the water level in a cool spot indoors in your garage or home so it does not overheat.