How to Remove Nitrates from Pool Water

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You might not like this answer. It’s simple, but it’s definitely going to increase your water bill.

Step 1: Drain Your Pool

It’s the only step. Draining your pool is the best way and only way to remove nitrates from your pool. There is probably a more elegant solution that hasn’t been discovered, but this is the one that pool owners are using today. 

Nitrates Are in City Water and Filtration Is Too Expensive

It’s going to vary from city to city, but nitrates are generally going to have a significant presence in city water. Reverse Osmosis filtration has the capability of filtering out nitrates, but it isn’t a realistic option. The basic price tag starts at roughly $50,000 and goes up from there, expensive resorts are pretty much the only pool owners in the market for such a system.

What Are Nitrates? What are Nitrites?

Nitrates (NO3) are polyatomic ions that…none of that matters. They are plant food. In pools, they are algae food. When the nitrate levels in your pool are high, algae becomes more of an issue. That’s why preventing them is so important.

Nitrites (NO2) are just like nitrates with the only difference being that they have one less oxygen molecule. Because they are submerged in H2O, it is very easy for them to find a molecule of oxygen to which they can bind to form Nitrates.

Can Chlorine Get Rid of Nitrates?

Unfortunately, the answer is no. When you add chlorine and shock your pool, the chlorine will break the Nitrates (NO3) into Nitrites (N02), but the Nitrites will quickly form right back into Nitrates. Long story short – It accomplishes very little.  

How Do Nitrates Get into My Pool?

It’s a good question. The answer is that nitrates come from everywhere, so you are going to have a difficult time preventing them. It’s even in the rainwater. In 2004, there was a study across 31 different states, and nitrogen was found in almost all of the samples that were taken. The amount of nitrogen in the rainwater can vary quite a bit due to the location and time of year, but it is almost always present. 

Here are some of the other common sources, but it is obviously not a complete list. A complete list would stretch all the way to the moon, and none of us have time for that:

  • Human Sweat
  • Animals: Dogs and Ducks
  • Fertilizer
  • City Water

How Do I Prevent Nitrates from Getting into My Pool?

As you can see, it isn’t a realistic goal to avoid nitrates, but there is a lot that you can do to limit them. Let’s go over a few good pool practices that can prevent too many of the nitrates from getting into your pool 

Keep the Animals out of the Pool

Dogs and ducks tend to lead the nitrogen-based assault upon the pool. Dogs run around plants that collect nitrogen. They also work up a tiny bit of sweat around their less furry bits. 

Sucks also carry nitrogen, but it’s their poop that’s the real problem. When these animals jump or fly into the pool, they make their nitrogen deposits. Ducks are enemy number one, since duck poop has a very high nitrogen content and ducks poop up to 96 times in a day. If you need some help, we have a guide that teaches how you can keep ducks out of your pool.

Shower Before You Enter The Pool

It is more than common courtesy. Showering washes away the sweat and grime, and much of that collected sweat contains nitrogen.

Don’t Pee in the Pool

Not only is it gross, but pee is also super-concentrated with nitrogen. In a high-protein diet, as much as 10 percent of that urine is pure nitrogen. Plants will eat that up and thrive. Make the rule clear to your less hygienic friends and family members, “No peeing in the pool!”

Keep Potted Plants Away From the Pool

While they do look pretty and they won’t do much harm, potted plants can be a source of problems for pool owners. The holes at the bottom of the pots become an escape for nitrogen. As we mentioned earlier, nitrogen is plant food.

If you are taking care of your plants by watering and fertilizing them, the nitrogen dense fertilizer will run through the pot and out of the holes at the bottom. When rain falls and pool water splashes, that nitrogen that leaked onto the pool deck will make its water into the water. It might take a while, but it will happen eventually.

Potted plants can also be a source of worms which is another headache that many pool owners encounter. If that is a problem that you are currently facing, we have a guide on how to keep worms out of your pool that you can read.

Pool Cover and a Pool Cover Pump

It seems like every article that we write mentions that buying a pool cover will solve the problem. In this particular case, it won’t completely solve the problem. However, it is probably the biggest band-aid, and it is the closest measure that can be considered a solution.

The cover will keep out the dogs, ducks, and rainwater. If you want to keep the rainwater out, you will probably need to add a pool cover pump. It will keep the water from pooling and eventually run over the pool cover and into the pool.

Can You Test for Nitrates?

If you think that you have a nitrate problem, you can test to find out how concentrated the nitrogen content of your pool is. There are testing strips on Amazon that are inexpensive and will quickly let you know how much nitrogen is in the pool.

The Pool Care Handbook & Video Course

by Swim University
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