Are you experiencing cloudy or dull-looking pool water even after adding the right chemicals? You’re not alone. Often, water problems are traced back to a misunderstood or underperforming filtration system rather than chemical imbalances. This guide explains how effective filtration works, what system you might have, and how to keep your pool sparkling with less hassle.

Why Is My Pool Water Cloudy Even After I’ve Added Chemicals?

This common question frustrates many pool owners. You’ve followed the chemical instructions precisely, yet your water still lacks the clear quality you want. The issue often isn’t your chemicals at all – it’s how your filtration system captures and removes particles from the water.

Each day, your pool collects contaminants: skin cells, sunscreen, leaves, dust, and microscopic organisms. A properly functioning filtration system traps these particles and prevents them from causing cloudiness or becoming food for algae.

When your filter isn’t performing at its best, these particles remain in the water, creating a cloudy appearance that no amount of chlorine seems to fix.

How Does Pool Filtration Work?

Your pool’s filter system works much like your lungs – drawing in water with contaminants, trapping the unwanted particles, and returning clean water to the pool.

This process relies on a simple but effective cycle. Your pump pulls water from the pool through skimmers and main drains. The water travels through the pump and gets pushed into the filter, where contaminants are trapped. Clean, filtered water then returns to the pool through return jets.

For effective filtration, your entire pool volume should circulate through this system at least once daily, and most pools are designed for an 8-hour filtration cycle – typically divided into two 4-hour periods.

What Type of Filter Does My Pool Have?

What type of filtration system do you have? Many pool owners inherit their systems with home purchases and never receive proper instructions.

Here’s a quick way to identify your filter type:

•     If you see a large tank with a multiport valve on top and a pressure gauge, you likely have a sand filter. These typically require backwashing through a waste line.

•     If you see a tall cylindrical tank with a lid that can be removed to access a pleated cartridge inside, you have a cartridge filter. These require periodic removal and cleaning of the cartridge.

•     If you see a grid assembly inside the tank that’s covered with a fine powder coating, you have a D.E. (Diatomaceous Earth) filter. These use a fine powder to trap extremely small particles.

Sand vs Cartridge Filters: Understanding the Differences

How Sand Filters Keep Your Pool Water Clean

Sand filters work like sieves for your pool water. The rough edges catch debris as water flows through a bed of specially graded pool sand. When the filter becomes clogged, you reverse the water flow (backwashing) to flush contaminants to waste.

Sand filters catch particles as small as 20-40 microns – about half the width of a human hair. They’re reliable, straightforward to maintain, and the media typically lasts 5-7 years.

However, their main drawback is water wastage during backwashing. A typical backwash uses 300-500 litres of water, meaning higher water bills and more frequent chemical adjustments.

Why Many Pool Owners Prefer Cartridge Filters

Cartridge filters use a pleated fabric material that traps smaller particles – down to 10-15 microns. This finer filtration often results in clearer water than sand filters provide.

These filters don’t require backwashing. You simply remove the cartridge periodically and hose it off, saving significant amounts of water. The cartridges typically need replacement every 2-3 years.

The main trade-off is more hands-on cleaning, but many pool owners find this offset by water savings and improved clarity.

Is Your Filter The Right Size For Your Pool?

An undersized filter is like asking a vacuum cleaner to clean a house without ever emptying the bag – eventually, it simply can’t do its job.

Signs your filter might be too small include:

•     Pressure gauge rising quickly after cleaning
•     Needing to clean the filter more than once weekly
•     Persistent cloudiness despite proper chemical levels

The right-sized filter should handle your pool’s volume comfortably. For sand filters, look for a filter tank diameter of at least 600mm for pools up to 60,000 litres. Larger pools need proportionally larger filters.

For cartridge filters, the surface area is key. Most residential pools need at least 4.5 – 7 square metres of filter surface area, with larger pools requiring 9 – 14 square metres or more.

The Enviro Smart Mineral Pool System

After understanding traditional filter options, many pool owners ask us if there’s a better solution to sand and cartridge systems. At Blue Haven, we offer the Enviro Smart Mineral Pool system, an advanced filtration technology combined with mineral water treatment.

This system brings together three key elements:

• First, its mineral sanitisation uses magnesium chloride, sodium chloride, and potassium chloride to reduce chlorine needs by about 50%. These minerals work with small amounts of chlorine to kill bacteria, making the water feel softer on the skin and eyes.
• Second, the extra-large Enviro Smart filter cartridge contains Microban technology that prevents bacteria growth within the filter itself. This means cleaner water and less frequent cartridge replacement.
• Third, the system reduces backwash water waste by up to 80% compared to sand filters, saving thousands of litres of water annually and keeping your chemical balance more stable.

Could the Enviro Smart Mineral Pool system solve your water clarity issues? Call our experts at Blue Haven today at 02 9728 0444 for specific advice tailored to your pool.

The Science Link Between pH and Filtration Efficiency

Many pool owners don’t realise that water chemistry directly affects filtration performance. Even the best filter can’t work properly when your pH is unbalanced.

Water with improper pH prevents particles from clumping together (flocculation), making them too small for your filter to trap. The ideal pH range for effective filtration is 7.2-7.6.

If testing shows your water is too acidic (below 7.2), add sodium carbonate (soda ash) at approximately 10g per 1,000 litres. For alkaline water (above 7.6), use a pH reducer such as sodium bisulphate at similar concentrations.

Always adjust pH before addressing other water issues. Often, correcting pH solves filtration problems without additional steps.

When Should I Clean My Pool Filter?

Knowing when to clean your filter saves both unnecessary work and potential problems from delayed maintenance.

Your pressure gauge is your best guide. Note the pressure when your filter is clean, then clean it again when the pressure rises 8-10 psi above this baseline. After heavy rain, pool parties, or algae treatments, check your filter regardless of pressure readings, as these events significantly increase the contaminant load.

How to Keep Your Filter Working at Peak Performance

Regular maintenance extends filter life and improves water quality. 

For sand filters:

– Backwash thoroughly until the water in the sight glass runs clear

– Add small amounts of aluminium sulphate (alum) monthly to improve sand’s capturing ability

For cartridge filters:

– Rinse from top to bottom to flush debris in the direction of the pleats

– Soak heavily soiled cartridges overnight in a cleaning solution

All filter types benefit from the same basic practices. First, run your pump during the coolest parts of the day to help prevent algae growth. Next, clean your skimmer and pump baskets every week to ensure smooth water flow and filtering. Finally, brush your pool walls regularly to loosen any particles or algae, allowing the filter to remove them effectively.

Solving Common Filtration Problems

Even well-maintained pools occasionally develop filtration issues. Here’s how to tackle the most common problems:

Why Does My Pool Get Cloudy After Rain?

Rainwater introduces contaminants that overwhelm your filter’s capacity. After rain:

1. Test and adjust pH immediately
2. Run your filter for 24 hours continuously
3. If cloudiness persists, use a clarifier to help your filter catch smaller particles

How Do I Fix Low Flow from Return Jets?

Weak water return often indicates filter problems:

1. Check and clean skimmer and pump baskets
2. Clean or backwash your filter
3. Check for air leaks in lines before the pump

Why Proper Filtration Matters for Health and Safety

Clear water isn’t just about aesthetics—it has a direct bearing on swimmer health and your pool’s overall longevity. Properly filtered water cuts down on eye and skin irritation, lowers the likelihood of bacterial infections, minimises damage to pool surfaces and equipment, and ultimately helps reduce chemical usage and associated costs.

For young children who might swallow water while swimming, effective filtration provides an essential layer of protection alongside chemical sanitisers.

Getting Professional Help with Your Filtration System

It might be time for expert assessment if you’ve tried troubleshooting but still struggle with water clarity issues. Our pool technicians can improve your current filtration system and recommend practical improvements. Often, simple adjustments or component replacements can dramatically improve performance without complete system replacement.

Call Blue Haven Pools on 02 9728 0444 or find your nearest store for guidance if you experience pool filtration challenges. Our team has helped pool owners achieve the crystal-clear water they deserve with practical, cost-effective solutions since 1973.