How Long to Wait Between Adding Pool Chemicals

When adding pool chemicals, waiting around 10 to 20 minutes between additions is recommended.

It’s important to understand that pool chemicals are made of strong gasses and concentrated materials. Mixing these or adding them too quickly back-to-back could potentially cause unintended consequences, including explosions.

While most chemicals are inherently safe, some precautions should be taken when adding multiple pool chemicals.

Why Should You Wait Between Adding Pool Chemicals?

Waiting 10 to 20 minutes between chemical additions gives the pool and filters enough time to circulate the chemicals.

However, there are different techniques and methods that you can use to ensure the pool chemicals get mixed as quickly as possible.

Speed up the Chemical Mixing

If you want to speed up the chemical mixing process, be sure to follow these simple guidelines:

Pour or spread chemicals slowly in front of the return jet in the deep end. The return jets will be an added boost to disperse the chemicals faster.
Turn your pool pump on its highest speed setting. Faster water movement will spread the chemicals at a quicker pace.
Brush the pool after each chemical addition. The goal is to disrupt the water as much as possible. This also ensures chemicals are not settling on the pool surface.

What Could Happen By Adding All Chemicals at Once?

There is a reason why you need to wait between adding pool chemicals. A lot can go wrong by simply combining or mixing chemicals before adding.

Please take caution and consider the potential dangers associated with mixing.

Wrong Chemistry Readings

Chemicals need time to mix in and circulate in the water. Each addition can potentially impact the reading of the previous chemical.

Ideally, focus on one chemistry reading at a time. If the focus is on calcium hardness (CH) first, don’t add chlorine to increase free chlorine (FC) levels between calcium additions.

Potential for Explosions

Remember, you are dealing with chemicals! A lot of chemistry is involved, and many chemicals do not play well with others. Pool chemicals are no exception to that rule.

Never mix chlorine with other types of chlorine, either by mixing it outside the pool or adding it to a feeder. Cal hypo shock in particular should never be added to a feeder previously used with another type of chlorine. This reaction can cause an explosion.
If diluting chemicals, always add the chemicals to a bucket of water, not vice versa.
Do not add or mix muriatic acid and chlorine. Any close interaction can produce a toxic gas that is extremely dangerous, even at small doses.
To be safe, never add any pool chemicals to one another.

Get Back to Swimming!

Under most circumstances, you should be able to swim about 10 – 20 minutes after the last chemical addition. If you still can see chemicals or the water doesn’t look normal, hold off on jumping in until conditions are normal for your pool.

The bottom line is to be smart and safe when handling chemicals. Follow your test results, add the necessary dosages, and return to swimming!