How Much Algaecide To Put In Pool For Winter (Answered)

The colder the temperature gets, the colder the water turns. And as such, the growth rate of algae in your pool in this winter period begins to slow down.

Although not completely though. Algae can still be found in some pools during winter. But what do you do to prevent the growth of algae in your pool during winter? We have listed the possible chemical to use for algae and also the quantity you are supposed to use in your pool when you are drawing into the winter season.

So in this article, you will be learning how to do that.


How Much Algaecide To Put In Pool For Winter

What Quantity Of Algaecide Can You Put In Your Pool For Winter?

Even as the growth rate of algae slows down during the winter season, you should add at least a dose of an algaecide once every week. That is if you maintain free chlorine levels in your pool. By free chlorine level, we mean, having a chlorine level between 3-4 ppm.

A winter algaecide is usually equalized with the amount of water in your pool. Generally, for every 10,000 gallons of water, about 16 ounces of algaecide is used. So while wintering your pool, this must be considered before the pool starts to close for the winter season.

Meanwhile, it is best to wait until the chlorine level drops in the pool to shock it with algaecide. But at what point do you put an algaecide before closing the pool? You should put algaecide in the water with the right quantity for about some hours before pool closing.

Weekly Application

However, weekly, you can apply algaecide in your pool about 16 ounces for every 10,000-gallon size pool. Spread the algaecide into the pool and allow the pool pump to keep running. And just in case your pool is heavily infested with green algae, then you should mix the algaecide with the right quantity of water.

This will help to saturate the pool, and also prevent the algae from spreading further. If your pool is about 10 ft which is around 1000 gallons of water, then it means you need just a little quantity of winter algaecide. Use about 0.13 ounces of algaecide.

If you own a 3000-gallon size pool, then you will need 0.75 ounces of algaecide. Ensure that you do not add more than this measurement because it might just be too much. So the amount of winter algaecide is largely dependent on the amount of water your pool holds. So get the measurement right!

pool in winter

What Happens To Your Pool During Winter?

The winter period is certainly no excuse for you to ignore pool maintenance. You need to ensure that the pool has a proper chemical balance otherwise, if you don’t it may cause you a lot of products, and probably equipment in the pool that needs replacement in spring. And that may not be good for you as the pool owner since you will have to spend afresh.

During the cold months, your pumping operation should be reduced, and the water should be tested at least once every week to check for chemical balance because, during the winter period, a chemical imbalance can occur. Chlorine can suddenly get evaporated too quickly.

So in this case, use a lot of chlorine tablets to prevent this, and also ensure that you reduce the setting on the chlorinator to about 2 to at least 4 ppm. So that the chlorinator can produce a steady amount of chlorine for your pool. Your pool’s pH is also likely to fluctuate at this point.

Ensure that it is maintained to be around 7.4 at least. However, if your pH level is high, it will promote scale buildups which can be unsafe for your pool. And if the pH of the pool is low, the pool walls, surfaces, and equipment might begin to harbor corrosion which is not good for your pool equipment.



Another thing that happens to your pool during the winter period is the fact that your pool’s alkalinity level begins to buffer. The normal alkalinity level should be around at least 80 to 120 ppm. Anything more than that will result in acidic water.

Another thing that happens is the hardness of calcium in your pool. When the calcium level in your pool is too low, your pool plaster becomes the victim.

It begins to etch and stain when the calcium level is too high, it leads to unnecessary stains and damage to your pool surfaces and finishes. Simply maintain a calcium level of 200 ppm for winter.

You also need to maintain the pool water with a stabilizer to at least 40 ppm to reduce the degradation of your chlorine when it comes to UV rays. You know that the winter sun will not be as strong as that of the sun in the summer period.

So maintain it at that level so that you can operate well.


Read: How Much Algaecide Should You Put In Pool When Opening


Is An Algaecide Necessary For Winter?

It is just like asking if an algaecide is necessary for a pool with algae. When you are about to close your pool for the winter period, or you are simply preparing your pool for the winter period, do not forget to use an algaecide.

An algaecide is simply one of the first chemicals that should be considered while preparing for the winter period. Such that, if you don’t want to get too shocked after the winter period, then make use of an algaecide. Algaecide is simple and quite effective when used.

So since you are winterizing your pool, get a winter algaecide, and use about one quarter in quantity. Add it to your water that is if you have 20,000 gallons of water pool size. If you have a 5,000-gallon size, you may have to measure it accordingly so that the algaecide will not be too much.

Simply adding a winter algaecide into your pool, can prevent the growth of algaecide in your pool. So for an easier pool opening sometime in spring, simply use an algaecide.


What Does Winter Algaecide Do To Your Pool?

Your winter algaecide can be added directly into your pool water and then the pump should be left turned on to enable perfect circulation for about three or four hours. So when a winter algaecide is added to your pool water, there are many things that it does to your cold pool water all winter long.

1. A winter algaecide is designed to automatically curb the growth of algae including the yellow, green, and black algae.

2. A winter algaecide will also hinder the growth of algaecide during winter so you can worry less during the cold months about troubling algae.

3. Also, your winter and copper algaecide will last longer during the entire winter period because it has been specifically designed to fit cold weather algae.

4. Also bear in mind that, adding an algaecide during winter to your pool water, doesn’t by any means interfere with the other chemicals in your pool.

5. The winter algaecide will help hold your pool water for at least 5 to 6 from algae. So to be sure that your algae remain completely under control, you will need to check your pool again and add algaecide to it after 5 or 6 months when winter is over.

Also, you should be sure to always inspect your pool cover for any kind of tears and rips because sometimes, winter covers may not be properly sealed. And this may reduce the effectiveness of the pool if the pool cover has any rips and tears.    So after you must have put winter algaecide in your pool, still check for a classic pool winter cover that is at least lightweight, and completely easy to install. Also, check if it is made from durable materials to prevent ripping and tearing.


Best Winter Algaecide For Pools

One of the best winter algaecides that you should consider using for your pool is the ‘In The Swim Winter Swimming Pool Algaecide‘. This particular winter algaecide has an effective algaecide formula that aids in preventing the growth of all kinds of algae.

Although this winter algaecide can only remain active for about 5 months that is if your pool is covered. It has a unique and potent formula that allows for other pool chemicals to remain balanced and effective.

So even if you have an above-ground or an in-ground swimming pool, you can totally get this winter algaecide to keep your pool free from intruders called algae! You will also notice that your pool opening during the spring period becomes easier as well.


Final Thought

The best part of the winter algaecide is that it doesn’t foam. It is a non-foamy algaecide. Remember that, the quantity of algaecide to be deposited into the pool should be about 16 ounces for a 10,000-gallon pool but if it is a 20,000-gallon size pool, you should put about 1 quart. Over it all, you should watch carefully, the amount of algaecide you put in your pool before closing it for winter.

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