Pool Alkalinity Adjustment

Your pool alkalinity is a big part of your pool water chemistry; therefore it is very important that you test it on regular basis. When you are correcting your total alkalinity level, it is recommended that you do so in small increments. Reason being, that it is much easier for you to adjust your TA Level slightly when it gets a little high or a little low.

You should not wait for your total alkalinity levels, to get way off and then try to bring it back under control all at once.

Since you are adjusting your pool alkalinity in increments, it is a good practice to re-test about 24 hours after each adjustment.

This process will let you know if you have reached your desired TA level or if you need to continue.

Raising your pool alkalinity level

Your pool water care requires you to maintain a proper TA level at all times. In doing so, you may have to raise your total alkalinity so that you always have an alkaline environment in your swimming pool. Remember your total alkalinity governs your pH. To raise your alkalinity level, you will have to add a pool care chemical called sodium bicarbonate. This pool chemical is also referred to as baking soda.

Still you must be aware that sodium bicarbonate will also cause an elevation in your pH levels as well. There are times when you may just want to raise your pH levels without affecting your total alkalinity. You can accomplish this by adding Soda Ash to your pool water.

Soda Ash is by no means the same as Baking Soda. In other words, it is not sodium bicarbonate. The table below gives a clear indication of what amount of sodium bicarbonate you will need to add to achieve a proper level of total alkalinity.

Increasing your total alkalinity using sodium bicarbonate

The recommended dosage when using baking soda (100% sodium bicarbonate) to raise your pool alkalinity for a certain volume of pool water.

Desired increase in PPM1,000 gallons5,000 gallons10,000 gallons20,000 gallons50,000 gallons100,000 gallons
10 ppm2.24oz11.2oz1.40lbs2.80lbs7.00lbs14.00lbs
20 ppm4.48oz1.402.80lbs5.60lbs14.0lbs28lbs
30 ppm6.72oz2.10lbs4.20lbs8.41lbs21lbs42lbs
40 ppm8.97oz2.80lbs5.60lbs11.2lbs28lbs56lbs
50 ppm11.2 oz3.50lbs7lbs14lbs35lbs70lbs
60 ppm13.4 oz4.20lbs8.41lbs16.8lbs42lbs84.1lbs

Now you should never try to add more than 10 pounds of sodium bicarbonate at any given time. The correct procedure would be to add what you can get away with, re-test after about 24 hours and then if more is needed, then you add again. It is possible that you may need to test and treat your recreational water facilities, for metals in solution before you can add any sodium bicarbonate.

A good practice to get into, is to premix or dissolve the baking soda in a bucket or mixing drum and then add the solution to the pool or spa. This procedure helps eliminate any signs of sodium bicarbonate from being visible at the bottom of your pool.

Decreasing your pool alkalinity using acids

There will be cases where you will need to lower the alkalinity level of your pool. Question is...how can I lower the alkalinity in my swimming pool? Well! This is usually accomplish using acids in liquid form as well in the form of acid salts. The most commonly used acids in the pool/spa industry, are muriatic acid and sodium bisulfate.

If you are face with a situation where you just want to lower your TA without seriously affecting your pH level, then you should pour the acid directly into the deep end of your pool.

Research has shown that by you creating pockets of extremely low pH, you can burn of your alkaline materials and safely reduce your alkalinity levels.

Before you can do any adjustment to your TA levels, you have to know exactly how much acid you will need to add to get your desired ppm level.

The table below can be used as a guide. Still you must add a small amount of muriatic at a time. This is usually 1 quart for every 10,000 gallons of water.

Decreasing your alkalinity using muriatic acid

Below is a table with the recommended dosage for using muriatic acid (31.45%), to decrease your TA for a given volume of pool water.

Desired increase in PPM1000 gallons5,000 gallons10,000 gallons20,000 gallons50,000 gallons100,000 gallons
10 ppm2.56fl oz12.8fl oz1.60pts1.60qts3.99qts2gals
20 ppm5.11fl oz1.60pts1.60qts3.20qts2gals4gals
30 ppm7.67fl oz1.20qts2.40qts1.20gals3gal6 gals
40 ppm10.2fl oz1.60qts3.20qts1.6gals4gals8gals
50 ppm12.8fl oz2qts4qts2gals5gals9.98-10gals

Whenever you attempt to lower your pool alkalinity, using muriatic acid, you should remember to add it at the deep end of your pool in pint size shots. Afterwards you should brush your pool/spa bottom to ensure that the acid does not settle in one area. The reason for this procedure is due to the fact that acid is heavier than water and will cause etching of pool surfaces.

Safety precautions when handling pool chemicals

When you have to deal with any type of pool or spa chemicals, you should always read the manufacturer's safety data sheets (MSDS). The information that they provide, will make you aware of the potential dangers of the product that you are dealing with.

Pool care is not an easy job and most of the times, we are face with dangerous and difficult situations but if we know how to protect ourselves and others, then we are half way there.

Special Note: You should never mix two pool or spa chemical together because the potential for creating a chemical bomb is enormous.

What you have to realize, not all manufacturers produce their chemicals in the same manner.

Because if they did, then we would have no need to worry about potential dangers.

So always follow the safety precautions and always wear protective gear (ie. face masks, chemical gloves, goggles) any pay close attention to any fumes that may occur as a result of adding chemicals to water.

Although there are many pool chemicals on the market that are used in pool care maintenance, your safety and that of others should always be first. So ALWAYS read the MSDS before making any attempts raise or lower the level your pool alkalinity.

Your pool alkalinity helps control waterborne illnesses!

Swimming pool care home page

POOL SAFETY PRODUCTS AND POOL ALARMS

Back To Top

New! Comments

Have your say about what you just read! Leave me a comment in the box below.