The Essentials You Must
Know Before Buying A Pool

What is Better? Chlorine, Saltwater or Mineral Pools

Which usually boils down to “I don’t want to get red, irritated eyes like I used to at the local community pool”. Or “Does one type keep my pool water cleaner and healthier?” Fair enough.

Let’s start with why you need chlorine in your pool. Chlorine kills the bacteria, algae and other yukkies (highly technical term!) that will be in your pool. It is why there is chlorine in our tap water and usually in bleach too. It keeps your water sanitised and safe and to swim in. Noticed the neighbours pool has gone green? Not enough chlorine! There are three ways to chlorinate your pool that we will talk about here - chlorine, salt or minerals.

If you would like to know more about freshwater pools, please click here to read our freshwater pool blog.

Chlorine

Chlorine can be added directly to your pool water either as a dissolvable tablet, a liquid or in granular form. If you used to see your Mum or Dad throwing strong smelling stuff from a bucket into your pool every other day in summer, you had a chlorine pool. As it is a manual process, the challenge is maintaining a stable level of chlorine.

When a dose is added, chlorine levels peak and then slowly reduce until more is needed. If you were swimming and your eyes became red and irritated, your hair smelled funny and your bathers had faded, you were in a chlorine pool that had been recently dosed. In summer, with kids in the pool every day, daily chlorine testing and dosing is usually needed.

You might be thinking “There must be an easier way?” – Well, enter the saltwater chlorinator!

Salt Water

Saltwater chlorinators work by converting salt added to your pool water, into pure chlorine. A salt cell next to your pump and filter produces a continuous bacteria-killing supply of chlorine while the pump is running. It is like being the manager of your own chlorine factory without ever having to touch a bottle or tablet of chlorine. Your pool water will feel softer without the eye irritation and strong smells as your chlorine levels won’t peak and trough. This is why almost all backyard pools bought in the last 20 years are saltwater pools.

Pool salt is cheap and normally can be bought in 15kg and 20kg bags. You will spend around $100 to $150 on salt per year depending on your pool size. No need to clean out the local supermarkets supply of table salt! Phew! Your pool will not taste like the ocean either. There is not enough salt in the water to taste it.

While pool salt is cheap, a quality Australian made, entry level, self cleaning (meaning the salt cell) automatic chlorinator will cost between $1,000 and $1,800. A model that can be controlled from your smart phone and measures water pH, water santisation levels and can automatically adjust dosage can be up to $3,000. With the money saved on chemicals and time maintaining your pool, you will be in front financially in a year or two no matter what you choose. Our fibreglass pool kits come with Australian Made Astral equipment and we have a full range depending on your budget.

Warranties range between 2 and 5 years. Check to see if they are full warranties or prorated. After about 3 to 5 years, you will need to replace the salt cell which will cost between $300 and $600.

As saltwater chlorinators are fully automatic you need to keep less of an eye on your chlorine levels compared to a traditional “add the chlorine in manually” pool. We humans can be a little on the lazy side at times which means we are tempted to set and forget. You will still need to check your chlorine levels regularly. Too much chlorine can damage your pool and equipment and too little will invite an algae bloom.

Mineralised

The solution to reducing the slight drying feeling of a saltwater chlorinated pool is to mineralise your pool by adding potassium and magnesium. Potassium is a natural moisturiser. Magnesium gives your water a soft, silky feel and also acts as a natural sanitising agent. 

Us humans absorb around 400ml to 500mls of pool water per hour of swimming until we get water logged (otherwise known universally by kids as "granny hands"). The benefits of magnesium on hair, skin and muscle health are well established and plenty of swimmers prefer to be absorbing minerals rather than chemicals.

Check to make sure the minerals are farmed and rated “food grade” so you know you are getting the highest quality and concentration for your hard earned money. The idea of minerals from the "Dead Sea" is pretty enticing as it sounds so natural. Being natural is the issue. The quality, amount of contaminants and concentrations vary with every bag as it is naturally produced.

While magnesium and potassium are different to pool salt (sodium), they are also salts.  You can mineralise your pool using a standard saltwater chlorinator. This is the lowest-cost way to mineralise your pool as you don't need to replace your saltwater chlorinator.

When first adding minerals to the pool after installation, the cost of the minerals will be between $300 and $1,200 depending on the size of your pool. A rule of thumb is 40kg of minerals per 10,000 litres of water. You will need to top up your mineral levels as you would a saltwater pool. On average, this will be a 10kg bag every 8 to 12 weeks costing around $50 to $60 per bag.

What Pump Do I Need? Single, Two, Or Variable Speed

You need a pump to circulate your pool water through the filter and chlorinator, to remove organic matter and particles that bacteria feeds off and to distribute chlorine and other added chemicals around your pool. Without a good pump, it is like half stirring the milk and sugar in your coffee. Seeing this is not Pump School, how about we keep the technical stuff short?

Your pump will push out a set number of litres per minute (LPM). Multiply that number by 60 (minutes per hour), then divide that into the total litres in your pool to get the number of hours to run your pump per day. This will circulate the entire volume of your pool 1.5 times each day which is what is required during an Australian summer.

Like a short cut? As a general rule, 8 hours per day in summer will do the trick and about 4 hours per day if the pool is not being used in winter. Got it? Let’s go pump shopping!

The first step to pump-buying glory is to understand how your pool uses your pump. Most buyers don’t realise that everyday filtration only needs a low flow rate compared to running a suction cleaner, manually vacuuming a pool or backwashing a media filter. Filters work better at lower flow rates as the water passes through your filter with less turbulence and collects more particles.

Single Speed Pumps – Low Energy Efficiency Rating

These pumps only run at one speed – full power. They have been in use for decades and work perfectly well. They were invented before power costs became a talking point and pools didn’t have heaters, water features and spa jets.

They range between in size 140 and 500 LPM depending on your pool size. If your pool needs 300 LPM to properly backwash the filter and run the pool vacuum and only 100 LPM for daily filtering, you will end up running a 300 LPM pump 8 hours day.

This is the main reason why pool pumps are the second highest power user in your house behind air-conditioning.

Many people tend to buy the smallest pump they can get away with to keep the power bills down. With an undersized pump, when your pool is being used constantly in summer, you will need to run the pump longer to keep your water clear and sanitised. Not only will this wear the pump out faster, any money saved buying the pump will disappear with higher power bills.

Single speed pumps are the cheapest to buy initially. However, they are often the most expensive when you add in power costs over a year or two. If a single speed pump suits your budget, go for it, however choose a quality Australian made brand. A cheap single speed pump ($500 to $800) will be noisy and need to be replaced earlier than a quality pump ($800 to $1,300). A good way to gauge quality is to compare how loud (decibels) the pump is when running.

Two Speed Pumps- Average Energy Efficiency Rating

As we now know, pumps do not need to operate at the maximum LPM rate to maintain a healthy and sanitised pool. Circulating water can be done at 10-15% of your pumps flow rate. Two speed pumps solve this problem. They have a low speed setting for daily circulation and filtering and high speed setting for running a manual vacuum or backwashing a media filter.

While more energy efficient than their single speed friends, the two speeds are fixed so it is important to get the right pump for your pool. If the low speed setting is too low, you’ll need to run it for longer which wipes out the power savings. A two speed pump will cost around $200 to $300 more than an equivalent single speed pump.

Variable Speed Pumps– Very High Energy Efficiency Rating

A variable speed pump allows you to have multiple speed settings (high, medium, low) that you can program in. Backwashing the media filter needs a quick push button change to the high speed setting. Job done, select “low” speed for daily filtering. As filtering is going to be the most frequent use of your pump (90%), the energy savings on low speed will give you a kid in a lolly shop type smile. You will reduce your annual power use by around 85% and your pump will last years longer than a single speed pump. Cha-ching.

The new generation of variable speed pumps achieve up to a 9/10 star energy efficiency rating and operate quietly on all speeds. (You’ll be on the neighbours Christmas card list now!) Variable speed pumps cost more initially, however your bank account will thank you after a year or so.

Key Takeaway – If you are thinking of buying a single speed pump for the low initial cost, you will spend a lot more in running costs than you save on the purchase and will need to replace it earlier as they work so hard. If energy efficiency and lower annual running costs are important to you, a variable speed pump is your best bet if you can afford the higher upfront costs.

We often recommend delaying a non-essential accessory to help cover the cost. After a year or so, you will have the spare money from saved running costs to pay for the delayed accessory. Win/Win!

What is the Difference Between a Media Filter and a Cartridge Filter?

Filters remove the organic matter and microscopic particles in your water that bacteria and algae like to feed on. Getting the right filter will mean the difference between safe, low maintenance, sparkling clear water or being on a first name basis with your local pool chemical shop constantly trying to fix water quality problems.

Ok, so the basics first. Your pump will draw water from your pool through the skimmer box and into your filter. This water is forced through either sand, glass or a mesh cartridge which traps the unwanted particles. Clean water is pumped back into your pool through the return jets (sometimes called “eyeballs”). It is very important that you match your filter flow rate to the pump flow rate otherwise filtering efficiency will be seriously impacted along with the longevity of your filter.

Media Filters –Sand

Unfortunately, we are not referring to a new app that filters out unwanted media ads on your smart phone. Media refers to what you choose to fill your filter with – either sand or glass. As you can see from the image, the filter bowl holds a fair amount of media (usually 80kg or 120 kg depending on pool size).

20 grade silica (sand) has been used for decades, hence the older term “sand filters”. Under a microscope, each particle of sand has jagged edges. It is these edges that capture the tiny particles in your water. Over about 5 years these edges are worn smooth, losing their filtering ability and need to be replaced. A mid- sized sand filter will hold around 120kg of sand which costs around $140 to replace. At an average of $28 per year, it is very cost effective.

Media Filter – Glass

You can also use crushed glass (glass media) rather than sand. Why? The glass particles are smaller and harder than sand so they capture smaller particles (down to 5 micron) from your water that are missed by sand. It takes around 7 years for glass to be worn smooth and needing to be replaced. 120kg of glass media will cost around $240. At an average of $34 per year, it will not break the bank however it is more expensive than sand. If you are expecting your pool to be continually full of kids (called high bather load), glass will do a better job of keeping your water crystal clear compared to sand.

Don’t they waste a lot of water? To maintain a media filter, the media needs to be cleaned every month in summer (or when the pressure gauge needle on your filter is pointing to red) by backwashing. Backwashing, as seen below, reverses the water flow direction through your filter which stirs up the media (it is like shaking a snow cone) releasing dirt and particles. The dirty water is discharged into your sewer line or soak wells. A backwash is simple to do, takes a couple of minutes. Sand media discharges around 300 litres of water per backwash whereas glass is around 180 litres.

Media filters generally cost between $600 and $1,200 with top end models up to $2,100. It is important to check what the outer shell is made from. If your filter will be continuously exposed to the sun, lean towards a fibreglass shell over injection mould plastic. Fibreglass is much more durable in the elements and will last a lot longer than plastic under the harsh Australian sun.

Cartridge Filters

If space for your pump, filter and chlorinator is tight, a cartridge filter has a much smaller footprint than a media filter. Inside is a cartridge that is usually several layers of fine mesh (like flyscreens however with much smaller holes). This mesh can filter smaller particles than a sand media filter and works much the same. Water is pushed under pressure through the mesh which traps the particles.

The cartridge can be easily removed and needs to be cleaned once per month initially. If you notice the cartridge is really dirty, you will need to clean it fortnightly. Or, every two months if it’s not that dirty after a month. High bather loads and pools with trees close by normally need more frequent cleaning. Cleaning is a bit more messy than media filters however still easy enough. Give the element an overnight soak in a cleaning solution and a good wash out and you are done. We recommend having two cartridges so your pump and filter can still run while one cartridge is being cleaned.

Cartridge filters cost between $500 and $1,100 on average, with top end models up to $2,200. Replacement filters cost between $100 and $300. If regularly cleaned, they need to be replaced every 3 to 4 years. Without regular cleaning, you might replace them annually.

Are Gas and Electric Pool Heaters Expensive to Operate?

This Depends On What You Ask:

1. Do you want to swim right through winter (less affordable) or extend the swimming season by a couple of months (more affordable)?
   
   
2. Do you want to take the chill off with 26 degree water temperature (more affordable) or want warmer 28+ degree water (less affordable)?
   
   

3. Is your pool concrete (less affordable) or fibreglass (more affordable)?

4. Is your deep end over 2m deep (less affordable) or a standard depth of around 1.7m (more affordable)?
   
   
5. Do you have a quality pool blanket in conjunction with your heater (more affordable) or no pool blanket (less affordable)?
   
   
6. Are you on mains gas (more affordable) or bottled gas (less affordable)?
   
   
7. Do you live in a warmer climate like Brisbane (more affordable) or cooler climates like Melbourne (less affordable)?
   
   

There are a lot of variables that make a significant impact on the operating cost of your pool heater. If you heat your pool, you will notice a difference in your gas or power bill. Most pool owners use heaters from mid-spring and from the end of summer to mid-autumn and heat to a more efficient 28 degrees. Adding 2 degrees, up to 30 degrees, can add 30% to the operating cost.

A quality (at least 500 micron and not the junk with a 2 year warranty on eBay) pool blanket makes a huge difference. At around $1,000 for a pool blanket and roller, you will save at least 50% of your annual heating bill which will offset the blanket cost quickly. A pool blanket will also naturally heat your pool water by up to 8 C which reduces how many heater running hours you need to hit your ideal temperature. Are they essential? No. However, without a pool blanket, it's like trying to heat your house with all of the doors and windows open. It’s possible if you are happy with a huge heating bill and double the upfront cost for a larger heating unit.

We’ve yet to find a pool owner with heating that regrets the decision however you need to make sure it is right for you.

What Are The Options?

Gas Heater

A gas heater is just like your instant gas hot water heater at home. Water passes through the internal piping exposed to gas flames which rapidly heats the water. A pump then pumps the warm water into your pool. As a general rule, allow around 24 hours to achieve a 12 degree temperature increase. Gas heaters run on Natural Gas (mains gas) or Liquid Petroleum Gas (LPG bottles) which is the same as the gas used in your house If you are on gas bottles rather than mains gas, consider a heat pump as gas heaters can use up gas bottles quickly.

Like any heater (inside or out), energy efficiency is paramount. Gas heaters have a much higher litre per minute (LPM) rate than heat pumps which makes them gas hungry. A cheap heater won’t be efficient and will cost you more with higher gas bills. A quality gas heater with a five year warranty will relieve your bank account of between $3,800 and $7,700 depending on pool size.

Heat Pumps

Heat pumps are very similar to your reverse cycle air-conditioning at home. A condenser uses heat from the outside air to warm up your water. The LPM output rate is much lower than gas so heating up times are also longer. Allow 48+ hours for a 12 degree increase.

With the invention of heat pump inverters (the pump speed cycles down as the set temperature is achieved), they are now energy efficient. How efficient? Up to 20% cheaper to operate than gas.

Heat pumps can also be remotely controlled through your smartphone depending on the brand you choose. Quality brands will offer full warranties up to 3 years rather than “1 year on labour, 2 years on parts and 25 years on the heat exchanger”. Entry level inverter heat pumps start around $2,000 and can go as high as $13,000 for a monster sized unit that could heat the whole neighbourhood (ok, that’s an exaggeration).

What else impacts the size of the heater you need? How much sun your pool receives in summer, wind, elevation and the colour of your pool. Make sure your heater supplier is using a heating calculator that includes these points and is based on the weather in your postcode. Using a “Melbourne” table for rural Victoria is not going to be accurate.

What about solar heating? How much does it cost to run a heater in each State based on the different weather? Great questions - click here to read our full blog that explains all heating options in a lot more detail.

The Difference Between a Manual Vacuum, Suction Cleaner and Robotic Cleaner

Manual Cleaners

These are like your home vacuum. A vacuum head with rollers is attached to an extendable pole so you can push it around your pools floor. Suction comes from connecting a hose to the vacuum head and your skimmer box and turning on your pump. Just add a human (not usually the kids who actually use the pool!) and 30 minutes later you should be done. For the best water quality, manually brush down the walls and allow the particles to settle for an hour before vacuuming. If you have a variable speed pump, run your pump on high while vacuuming.

Suction Cleaners

Suction cleaners are an economical semi-automatic version of a manual vacuum and are set up the same way. The difference is you can throw it in the water and walk away. When the pump comes on, the cleaner will move around the pool floor and up the walls vacuuming everything in its path. As it moves around in random patterns, sections often get missed which need manual vacuuming or a broom down.

Plenty of people leave their suction cleaner in the pool for weeks on end which voids the warranty. Plastic and rubber seals do not like long baths in pool water. While saving you time, leaving it in the pool and connected will mean your pump will continuously run on the highest power use setting. It is best on your cleaner and pump if you remove the cleaner after each clean.

As the cleaner is attached to the skimmer box, leaves and other debris that would normally be skimmed from the surface will end up on your pool floor. The volume of water through the filter drops as well so monitor your water quality initially and increase your pump running time if it is becoming cloudy. Compared to manual vacuuming, you will be relaxing by the pool in no time.

Quality suction cleaners range between $680 and $1,300. You will annually spend around $100 on consumables that wear out like diaphragms, retaining rings and tracks.

Robotic Pool Cleaners

We so want to make a Lost in Space reference here. Alas, no. If you are looking for a cleaner that will learn the shape of your pool, can be controlled from your smartphone and is completely independent of your filtration system, you might start mumbling “top of the range robot pool cleaner” in your sleep.

Traditional robots plug into a standard power point. A transformer in the unit converts the power to a safe low voltage level which in turn powers the wheels or tracks that move it around your pool. (Yes, it’s a long power cable!).

Being low voltage, they are very economical on electricity use. As they do not rely on your pump and filter to operate, your skimmer box will collect surface debris and your pump can run on its lowest power setting for daily operation while your robot cleaner goes to work.

If plugging in and packing away power cables doesn't float your boat, consider a battery-powered robot (yep, no cables). The market is currently flooded with cheap Chinese brands that are total rubbish. With battery-operated robots, you get what you pay for. Look past the fancy brochure and cool looking robot and only buy a robot that offers 500 operating hour battery warranty backed by a major brand.  That is your sign of quality. A long warranty from a new company without an office in Australia isn't a good sign.

The robot vacuums straight into its own filter basket (like a house vacuum) and will suck up all sizes of debris. Robots can scrub your floor, walls and waterline saving you from manually brooming your pool. As the debris is not going into your filter, you’ll notice your filter will need less backwashing or cartridge cleaning and your chemical consumption will drop.

Just like suction cleaners, leaving your robot in the pool for days and weeks on end will void the warranty.

The downside is with all that extra time relaxing next to your pool, you’ll be able to think about what your new robot friend cost. Quality entry-level models that scrub the pool floor, waterline and walls will start at around $1,200. All the bells and whistles functions are up to $2,800. Start dropping Christmas present hints early!