Which salt water pool chemicals does a pool owner need to keep their pool running? Despite what you may have heard, salt water pools do require the use of some chemicals including chlorine. While a salt pool chlorinator converts salt into chlorine to keep a pool sanitized, there are occasions where chemical chlorine and other chemicals are needed to keep water chemistry in check.
Below are the chemicals I’ve used in my salt water pool over the years and the reason for using each. It’s my own personal salt water pool chemicals for dummies list.
Salt Water Pool Chemicals For Dummies
Salt
I use regular water softener salt in our pool. I typically a toss a large bag of salt into the deep end during spring opening, and a smaller bag (and sometimes a second small bag) midway through the summer to keep salt levels in check. You run salt between 2700-3400 parts per million (PPM) in a salt water pool and I generally run the system around 2800-2900 PPM or so.
Chlorine
I’ve used:
- Liquid chlorine to open the pool in the spring to help the system start producing chlorine after a winter of no chlorine production.
- Liquid chlorine at closing in the autumn to help keep the water as clean and clear as possible when the pool system is shut down and not producing chlorine over the winter.
- Powder chlorine during 2 different summers when the chlorinator cell died and it took me a few days to get a new one delivered. I used this chemical chlorine to keep the pool sanitized in the meantime.
- Shock crystals which come in a small packet and are often added directly to the pool or mixed with water first and then added. I used this in cases where I needed to quickly raise the chlorine levels ie. cloudy water, small amounts of algae, spring pool opening.
I also used chlorine pucks on occasion when the salt chlorinator died and it took us over a month to get the Hayward AquaRite system installed to replace it.
NOTE: Shock comes in many forms but the names you’ll probably come across the most are Cal Hypo (Calcium Hypochlorite), Dichlor (Dichloroisocyanuric Acid) and MPS (Sodium Monopersulfate). I’ve used the first two products but mostly Cal Hypo as it’s the strongest and fastest working.
Algaecide
We already talked about getting rid of green algae and both black and mustard algae. In general algae occurs because of a lack of chlorine (green and mustard/yellow) or infestation from the air or dirty swimming clothes from a river, ocean or other body of water (black algae). Algaecide is a concentrated algae-killing liquid that helps to kill off algae growth quickly.
For the first few years we owned our salt water pool, our spring opening always took about one week to get right because the water was dark green and full of algae. Once we learned to close the pool with super chlorination in the autumn, the algae stopped.
Occasionally during the summer an algae breakout may occur that also needs to be dealt with. Algaecide helps to kill algae quicker than chlorine does. Once algae has set in, there isn’t enough chlorine in the world to kill it on its own. I tried using only chlorine in large amounts and never had success!
pH
The pH scale from 0-14 is used in a salt water pool to measure the acidity or basicity of pool water. So 7 is considered neutral. Generally the range for a salt water pool should be 7.2-7.8.
pH Up (or similar product) is used to raise pH levels.
pH Down (or similar product) is used to lower pH levels.
Some pool chlorinator systems even have pH control automation features now.
Alkalinity
Alkalinity is too high: Muriatic acid is used to lower the alkalinity levels in a salt water pool. I have used this typically in the spring.
Alkalinity is too low: Sodium bicarbonate is used to raise alkalinity levels in a salt water pool. I can’t recall ever having to raise alkalinity but it can happen.
Cyanuric Acid
This is like a sunscreen for chlorine. I use this during the season as per instructions to protect the chlorine from sun. Direct sunlight kills chlorine in a pool so Cyanuric Acid helps to protect it from UV rays and make it last longer.
You may also use a stabilized chlorine that has stabilizer already added.
Metals
Have you suddenly noticed copper, silver, iron or other metallic-looking stains on your salt water pool liner or walls? We had this several times and typically got rid of it with a metal remover product. It’s likely that one or more of your water measurements might be out of line ie. pH level might be high and may need to be lowered.
Some people suggest rubbing a vitamin C tablet or a chlorine puck directly on a stain to determine what type it is. In almost every case, my stains are in the deep end and I didn’t feel like diving down and trying to rub something on a stain.
Filter Cleaner
We have a Sta-Rite System 3 cartridge filter. I figured out after several years the benefits of a filter (cartridge) cleaner. I took our cartridges out of the filter unit, rinsed them, then popped them into a large garbage bin full of water, added a bottle of filter cleaner and let it sit overnight. I rinsed the cartridges again upon removing them from the solution and reinstalled them. The filter cleaner gets rid of oils and other contaminants that simple rinsing won’t do.
I really noticed a difference with cartridges that were already over a year old after soaking them overnight in the filter cleaner solution. The water flow from the return jets was much stronger and you could see the cartridges were much cleaner looking.
Super Clarifier
This was recommended by our pool company. You squirt an amount of it directly into the pool and upon circulation throughout the system, it helps the pool filter to filter our particles that it might normally miss. As per the name, it clarifies and clears up cloudy pool water and may reduce the need for chlorine.
Antifreeze
Because we live in a cold environment in the north that freezes in winter, our second pool company recommended pouring antifreeze into the skimmer after the water level was dropped, and after the lines were drained and capped. They poured antifreeze into the skimmer and then added the Gizzmo which is a collapsible plug that screws into the skimmer and protects it from freezing water expansion during the cold months. So if ice water seeps in the antifreeze should prevent it from freezing and cracking or otherwise damaging pipes.
Conclusion
As you can see there are still chemicals that do need to be added to a salt water pool from time to time to fix certain problems and keep water chemistry in line. These are the chemicals I’ve used over the years to keep our salt water pool running. You may experience the same or different chemical needs.
Check out my post on How To Winterize A Salt Water Pool as closing a salt water pool involves using some chemicals that you may not currently be using that could make your spring opening easier.