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Should You Use A Swimming Pool Flow Meter? (Hint: Yes)

Keeping an efficiently running pool is going to save you money not only on chemicals, but in operational costs as well.

Installing a pool flow meter will help monitor both the health of the pool water and the performance of the pool’s circulation system.

What Is A Pool Flow Meter?

A pool flow meter is a device that measures how fast water flows through the circulation system. It’s installed on one of the pipes, usually somewhere after the filter, as there’s virtually no obstructions in the water flow at this point.

The meter measures the amount of gallons per minute that flow through the pipe, which is referred to as the flow rate.

This rate varies from pool to pool, due to a number of factors: 

The type of plumbing, pipe size, your specific equipment, filter size, and even the location of the equipment in proximity to the pool will all play a role in determining flow rate. This makes a flow meter the easiest way to keep on top of water flow with accurate readings.

Why Use A Pool Flow Meter?

A flow meter helps you figure out exactly how much water needs to move through your filtration system to keep the pool clean.

Not enough and you end up with dirty water. Too much and you run your pump excessively, reducing its lifespan and racking up electricity costs at the same time.

For residential pools, turning over the water (cycling) must be done at least once a day. A full cycle happens when the entire volume of pool water has been through the circulation system and filtered.

Why is this important? Not only does it filter out pollutants in the water, but cycling also helps evenly distribute the sanitizing chemicals that are present in the pool water.

The flow rate of a pool can be determined using the following equation:

Pool Water Volume (in gallons) ÷ 6 (hours for a full water turnover) ÷ 60 = Minimum Water Flow (in gallons/minute)

For example, if you have a 20,000 gallon pool, your minimum water flow rate needs to be 55.55 gallons/minute in order to turn over the water in a 6 hour time frame.

With a flow meter, you can easily see if the circulation system is hitting this number, as it gives you a precise, real-time measurement. If the flow rate isn’t high enough, you’ll know immediately.

You can then take a look through the system to see where there may be obstructions that are hindering the flow of water. Removing these obstructions will restore the water flow to its full rate.

What Are The Different Types Of Flow Meters?

There are 3 types of flow meters that can be installed to work with your pool:

Analog

The old school option, analog flow meters are the least accurate of the 3 but also the most popular due to ease of installation, and cost.

This meter is transparent and upright, resembling a thermometer. It requires you to drill a hole in the top of your system’s PVC piping and clamping the meter onto it. On the underside of the meter is a small metal float which rests in the hole. The pressure from the water pushes it up, giving you your flow rate reading. 

An average price for this meter is around $100 for a 2” PVC pipe, although the price goes up if the pipe is larger.

Digital

Digital flow meters install and operate pretty much the same way as an analog meter, but due to their digital sensor technology, they can provide pool owners with a pinpoint accurate flow rate.

However, they also cost upwards of $500, which is quite a bit more than their analog counterparts.

Automated chemical control systems also contain a digital flow meter, providing a flow rate readout on their front panel.

These controllers measure the chemical levels in the pool and automatically keep it clean so you only have to do minimal upkeep. Keep in mind that these automated feeders are even more expensive, and you’ll pay at least $1500 for one.

Inline

An inline flow meter provides you with excellent accuracy but also requires advanced installation. The inline meter is essentially a joint that is installed into the pipeline. 

An inline meter will run you around $120 on average. If you’re comfortable with DIY projects you should be fine, but for those that aren’t as handy it might be a job you want to outsource to a professional.

How Do You Install A Flow Meter?

Analog meters are pretty simple to install, only requiring a drill and some bits. You’ll also need to ensure the directional arrow on the meter matches the water flow in the pipes. 

Positioning of an analog meter is usually after the filter to reduce instances of debris clogging it up. If you don’t have much space after the filter, you can install the meter before it, but be extra vigilant in keeping the pipes clear of debris.

  1. First, find a long area of pipe to work on. You’ll need to use a dry erase marker to mark 2 points on the pipe. 
  1. Calculate 5 times the diameter of the pipe for your starting point (ie. a 2 inch pipe means your starting point is at 10 inches). Then, calculate 2 times the diameter of the pipe for your end point. The empty space between those calculations is where the flow meter can be installed. 
  1. Drill down with a small bit to make your pilot hole, then open it up with a larger bit. Using sandpaper you can clean up any shredded PVC around the hole. The meter then rests on top of the pipe, with the metal float underneath going down into the hole. Finally, clamp it down to secure it to the pipe so there’s no leakage.

A digital flow meter comes with a saddle mount and can be installed the same way as an analog meter. The only difference may be the size of the drilled hole to accommodate the meter’s digital sensor. 

Some digital models also come “pre-installed” on a PVC or stainless steel pipe joint. This makes it so you only have to cut out a piece of your plumbing and replace it with the joint.

For digital meters on automated chemical feeders, they will most likely be installed by a professional. This is because they require a bit more expertise when connecting the various pumps and devices that it requires.

Inline flow meters require advanced installation skills. You’ll have to cut out a section of your PVC piping, and install the meter in its place. This means lots of precision measuring, as well as gluing and sealing the proper fixtures so there aren’t any leaks, and repainting the pipe so everything looks seamless.

Just Go With The Flow (Meter)

Any of these three pool flow meters will allow you to monitor your water flow, making them a must-have pool care tool.

Knowing how well the circulation system is performing will help you regulate the speed of your pool pump for optimal water filtration, and you’ll save money by always running it at the correct speed.

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