Mizu Aquatic Systems

08/08/2026

Is your pond filter running... but your water is still green or cloudy? 🤔

A running filter doesn't always mean it's filtering effectively.

Some of the most common causes include:
1. An undersized filter
2. Too many fish
3. An immature biological filter
4. Dirty filter media
5. Poor water circulation
6. Unbalanced water chemistry

Before spending money on a new pump or filter, it's worth finding the real cause of the problem. In many cases, the solution is simpler (and cheaper) than replacing equipment.

We've put together a guide explaining the most common reasons pond filtration systems struggle and what you can do about it.

📖 Read the full article here:
👉 https://www.mizuaquatics.co.za/pond-problems-solutions-faq/why-is-my-pond-filtration-not-working

If you're in the Western Cape and your pond isn't looking its best, Mizu Aquatic Systems offers professional pond health assessments to identify the root cause and recommend practical solutions.

Why is my pond filtration not working?

06/08/2026

❌ POND MYTH: A bigger pump is always better.

More flow must mean better filtration, right?

Not necessarily.

A pond pump needs to be matched to the pond, filtration system and plumbing it is actually operating with.

An oversized pump can push water through some filters too quickly, increase electricity consumption, create excessive flow and still fail to solve the underlying problem.

And the number printed on the pump isn't necessarily the flow you're getting at the pond. Pipework, bends, height differences and equipment all create resistance that reduces actual flow.

The goal isn't the biggest pump you can install.

It's the right flow rate for the system.

A well-designed pond works as a complete system...pump, filtration, plumbing, circulation and pond volume all need to work together.

💧 Bigger isn't always better. Correctly sized is better.

24/07/2026

❌ POND MYTH #2

"Doing more water changes will solve the problem."

Water changes are important.

But they aren't magic.

Water changes can dilute:

• Ammonia
• Nitrite
• Excess nutrients

What they cannot fix:

• Undersized filtration
• Poor circulation
• Inadequate aeration
• Overstocking
• Design flaws

If a pond requires massive water changes every week just to remain stable, there is often a deeper issue within the system.

Good pond management isn't about constantly fighting problems.

It's about creating conditions where the problems struggle to develop in the first place.

Treat symptoms long enough and they become expensive.

Fix causes and they often disappear permanently.

22/07/2026

WHAT HAPPENS DURING A POND HEALTH ASSESSMENT?

Many pond problems develop slowly.

Fish adapt.

Water quality gradually changes.

Filtration performance declines over time.

By the time obvious symptoms appear, the issue may have been developing for weeks or months.

A typical pond health assessment looks at:

• Water chemistry
• Fish behaviour
• Filtration performance
• Circulation and aeration
• Stocking density
• Organic loading
• General system design

The goal isn't simply to identify today's problem. The goal is to identify tomorrow's problems before they happen.

Prevention is almost always cheaper than emergency intervention.

Whether it's a residential koi pond, hotel water feature or estate pond, the principles remain the same: Healthy fish start with healthy water.

As a deliverable you will receive a detailed diagnostic report on your ponds condition and a pond health score out of 100 based on scientific principles. Repeat customers receive reports with all previous data points included to track trends over time.

20/07/2026

WHY DOES POND WATER TURN GREEN?

Green water is one of the most common frustrations pond owners face.

The surprising part? Green water is usually a symptom, not the actual problem.

Common causes of green water include:

• Excess nutrients in the water
• Overstocking
• Overfeeding
• Too much direct sunlight
• Immature biological filtration
• Insufficient plant competition

Many pond owners or maintenance companies immediately reach for chemicals or algaecides.

The usually only work temporarily.

But unless the underlying cause is addressed, the algae always returns.

Healthy ponds are built on balance:

✔ Control the nutrients
✔ Ensure adequate biological filtration
✔ Create good water circulation
✔ Maintain proper stocking levels

Algae is often the pond's way of telling you that something else in the system needs attention.

The question isn't: "How do I kill the algae?"

The question is: "Why is the algae thriving in the first place?"

Understanding that difference changes everything.

17/07/2026

❌ POND MYTH #1

"Clear water means a healthy water."

Unfortunately, that isn't always true.

Some of the most serious pond problems are completely invisible:

• Ammonia
• Nitrite
• Low dissolved oxygen
• Low alkalinity (KH)
• pH instability

A pond can look crystal clear while the fish are under significant stress. On the other hand, a pond could be murky but be perfect for the fish.

Water clarity is an aesthetic measurement. Water quality is a chemistry measurement.

Healthy ponds are built on stable water chemistry, sufficient oxygen and adequate biological filtration, not simply clear water.

The next time someone says, "The water looks fine," remember:

The fish experience the water very differently from how we see it.

15/07/2026

THE OWNER THOUGHT IT WAS DISEASE...

The fish had become lethargic. Several were spending most of their time near the waterfall.

The first assumption was parasites or bacterial disease. But fish behaviour can be deceptive.

After investigating the system, the real issue turned out to be poor aeration and inadequate circulation. The fish weren't sick.

They were oxygen stressed. No oxygen supply other than the waterfall.

This is one of the reasons pond diagnostics are so important.

Many pond problems produce similar symptoms:

• Low oxygen
• Water quality issues
• Overcrowding
• Disease
• Filtration problems

Treating the wrong problem can waste time, money and sometimes cost fish lives.

Not every fish health issue is a disease issue. Sometimes the answer lies in the water itself.

13/07/2026

WHY ARE MY FISH GASPING AT THE SURFACE?

Seeing fish spending time near the surface or gathering around waterfalls and aerators can be an early warning sign that something isn't quite right.

Common causes include:

• Low dissolved oxygen levels
• Overstocking
• Poor water circulation
• Excess organic waste
• Warm temperatures reducing oxygen availability

One of the biggest mistakes pond owners make is to immediately assume this behaviour means disease or parasites.

In many cases, the fish are simply trying to access water with higher oxygen levels.

Fish behaviour often tells a story long before water tests do.

If your fish are regularly gasping at the surface, don't ignore it. Early intervention is often the difference between a minor correction and major fish losses.

Mizu Aquatic Systems specialises in pond diagnostics, water quality assessments and identifying the root causes behind pond problems.

02/07/2026

What pattern caught your eye first? 👀

Kohaku? Showa?

Most people see colour. We see water quality.

Bright colours, active fish and healthy growth usually start long before you can see a problem in the pond.

Healthy water. Healthy diet. Healthy koi.

Bet you want to take'em all home😜

27/06/2026

Attended the opening of Nishikigoi House in Durbanville today. Great staff, beautiful koi for sale, great setup and most of all, it was amazing seeing how many enthusiasts and hobbyists showed up to support the event and industry in Cape Town. The future looks bright 😁