When it comes to koi keeping, one truth stands out: good water quality is key to healthy fish. Problems can still arise in ideal conditions, but bad water will always cause stress, disease, and even fatalities. That’s why learning how to test pond water and doing it regularly is vital. Why Testing Pond Water Matters In a filtered pond, nature doesn’t manage water quality—it’s up to you. Good clarity doesn’t guarantee safe water. A filter’s primary job isn’t just to keep the water looking clean but to biologically break down ammonia, a toxic waste product produced by your fish. Through a process called nitrification, ammonia is converted into nitrite (also harmful), then into nitrate (non-toxic). Prolonged exposure to elevated ammonia or nitrite levels is dangerous, even fatal, for your koi. Regular testing ensures you spot problems before they cause harm. Core Water Parameters You Must Test While you could test for many things, four parameters are essential: Ammonia Ammonia burns fish gills and body tissue. Even a short-term spike can cause lasting damage or death. You should aim for 0 mg/l at all times. Nitrite Nitrite poisons koi by damaging red blood cells, causing “brown blood disease.” It’s slightly less toxic than ammonia but still deadly. Keeping nitrite levels low is crucial for fish health. pH pH measures the acidity or alkalinity of your pond. Koi can adapt to a range of pH levels, but sudden changes are deadly. Aim for a stable pH between 7.0 and 7.5. KH (Carbonate Hardness) KH acts as a buffer, keeping your pH stable. Without it, dangerous swings can occur. A KH level of 6dH or higher provides good stability and supports the beneficial bacteria in your filter. How to Test Pond Water Effectively The best way to manage water quality is by owning a pond water test kit. Several types are available: Strips, liquid, and tablet kits are affordable, easy to use, and accurate enough for koi ponds. Electronic meters offer precise readings but are expensive and usually unnecessary unless you have a deep interest in water chemistry. Using these kits typically involves taking a sample of pond water, adding a reagent or using a dipstick, and comparing the result to a color chart. Electronic kits will give you a digital reading. If you can’t test the water yourself, many aquatic centers offer a water testing service—sometimes even for free. Always check their biosecurity policies before visiting, as bringing pond water onto a site can pose risks. How Often Should You Test? Being proactive is key. Test your pond water once a week to catch problems early. Over-testing wastes supplies, while under-testing risks missing critical changes. Keep a water test log to track changes over time. Patterns in the data can help you understand how your pond system is performing and highlight recurring issues. New ponds may experience fluctuations for up to 12 months. If you’re struggling to stabilize your water, seek advice from a trusted koi dealer. What to Do If Water Parameters Are Wrong Water quality issues can have many causes. If your readings aren’t right, consult an experienced koi dealer or hobbyist familiar with your setup. Online advice can be overwhelming and sometimes misleading. Always try to understand the root cause rather than applying a quick fix that won’t last. Getting Started with Water Testing Before buying your first koi, you should already own a basic pond water test kit. These kits are inexpensive—costing little compared to the value of your fish—and can save your collection from disaster. Understanding how to test pond water isn’t complicated, and mastering it is one of the most important steps in becoming a successful koi keeper.

Sleeper Pond Kit Delivery and Lead Times Explained How will my kit be delivered? Once your kit is ready to be shipped we will let you know it is about to be sent out., the haulier will contact you directly to arrange a suitable day and it will be delivered to your nearest curb side. The kit will be securely packed on a pallet, shrink wrapped, and banded together. This ensures that all the components of your kit stay intact during transportation. Certain parts of your kit will be sent separately, following feedback from previous customers that things like bolts and sealant had fallen off or become damaged. To start unloading your kit, you should first cut the banding that is holding the uppermost timbers. By doing this, you keep the pallet solid and reduce the chances of any parts falling off. Your Delivery driver may have a tail lift and a pump truck, these are for deliveries suitable for this equipment. Your kit is to be hand balled off the back of the wagon and this is your responsibility. If we deem it safe to do so we will include your glass in the main pallet, otherwise it can be sent separately. What about the weight of the timbers? The timbers in your kit can weigh up to 30kg each. Therefore, it is important to have a minimum of two people available for offloading. This ensures that the unloading process is safe and efficient. If you have ordered a very large kit, you may need additional people to help carry the glass. Glass can be quite heavy, some weighing over 100kg. The glass comes loose and you will need to have a safe place to store it. Can I choose a Saturday delivery? While Saturday deliveries are possible, they are usually more expensive. If you prefer a Saturday delivery, you can request a quote from us. We will provide you with the cost and make the necessary arrangements. What is the lead time? If your kit includes glass then the production lead time is estimated at 3 to 4 weeks, this is usually due to glass lead times being the same. Sometimes we have glass in stock and are able to send this out much sooner, please ask if this is possible. Once produced we aim to ship within a couple of working days. What makes our kits easy to build? Our kits come with pre-cut numbered sleepers, making the assembly process incredibly easy. You don't have to worry about measuring and cutting the sleepers yourself. Additionally, all the screws and bolts you'll need are included in the kit. This saves you time and ensures that you have everything required for the construction. What about the liner? Once you have constructed your kit we ask that you measure the internal sizes and provide them to us, this step ensures that your liner fits perfectly. All timbers are rough sawn which is not precise so we cannot predict the size that the kit will end up. Box Liners and underlay are sent out within 5 to 10 days following your measurements being sent to us. It is rare that it is longer than 6 days. Our kits come with a box welded liner made of 1mm Butyl. The liner simply drops into place, so there's no need for folding or complicated installation.

Acclimatisation tips: Settling new koi after delivery When koi arrive by courier, the way you handle them in the first few hours makes all the difference. They have travelled for a full day, sometimes longer, and while the bags keep them oxygenated, the stress is real. Rushing this stage or skipping key steps can lead to health problems that spread through your whole pond. Prepare Before Delivery: Make sure everything is ready before your koi arrive so they can settle in calmly and safely.   First Steps on Arrival: Place the box down gently and avoid rushing. Open it carefully, check the bags, and leave them sealed to rest. Koi can remain safely in oxygenated bags for up to 48 hours, so there is no need to panic. Allow them to rest for at least 1 hour (ideally 2–4 hours). Only shorten this time if a fish appears visibly stressed. This resting period is essential—rushing is one of the most common mistakes.   Acclimation Process: Take your time during acclimation to minimise stress: Float the sealed bag in your pond to equalise temperature Transfer the koi into a bowl Gradually add pond water to the bowl over time Never add bag water into your pond Slow acclimation is key to reducing shock and helping your koi adjust smoothly. To help your koi settle: Colombo Fish Protect – Helps calm koi and supports their slime coat Salt (0.3%) – Aids osmoregulation and reduces stress Colombo Alparex – Used during our import process; highly effective for helping fish settle   Signs of Stress to Watch For: It is normal for koi to experience stress after transport. This may show in several ways: Increased activity, such as jumping Hiding or “sulking” at the bottom or in corners Slight pinkness in white areas of the skin Adding new fish can occasionally disrupt the balance of your pond and affect existing fish. In some cases, this may lead to parasitic issues. Monitor all fish closely for the first few days and watch for unusual behaviour or health concerns.   Health Assurance All fish are mucus scraped and checked the day before shipping. If there is any doubt about their health, the fish will not be shipped, and you will be notified immediately. Health checks on arrival Every new koi should be checked before joining your collection. Even from trusted dealers, it is your responsibility to protect your pond and collection. The best way is to carry out a scrape. This means taking a small mucus sample from the koi (usually from just behind the head down towards the tail) and checking it under a microscope. Place it on a glass slide and look for parasites. The usual culprits to watch out for are flukes, Trichodina, or Costia. They are not always present, but when they are, you want to catch them before the koi goes into your pond. Think of this step as insurance. If the scrape is clean, you have got peace of mind. If not, you can treat straight away without risking your whole collection.    When to contact your dealer If you find parasites or any problems during your checks, don’t guess at treatment. Get in touch with the dealer straight away. A good dealer will give you advice on what to use and how to handle it. Sometimes it’s a quick fix, sometimes it needs a proper treatment plan. Either way, dealing with it early stops things from getting worse. Remember, koi are livestock. Even with the best care in preparation and shipping, issues can appear. What matters is how quickly and calmly you deal with them. Final Thoughts Settling new koi after delivery isn’t complicated, but it does take patience. Give them time to rest, acclimate them slowly, and use the right products to reduce stress. Never add shipping water to your pond and always carry out a health scrape. These steps protect both the new fish and your existing collection. Stick to the basics and you’ll keep your koi safe and healthy from day one.

How can I tell if my koi fish is sick? Koi rarely show obvious signs straight away. The earliest indicators are usually behavioural changes—such as flashing, isolating, reduced appetite, or sluggish movement. If a koi is acting differently from normal, something is likely wrong. What does it mean when koi are flashing or rubbing? Flashing (rubbing against surfaces) usually indicates irritation. This is most commonly caused by parasites like flukes, but can also result from poor water quality. It’s often one of the first warning signs of a problem. Why is my koi isolating or hiding? Healthy koi are social and active. If one is staying away from others, hiding, or avoiding feeding, it may be unwell, stressed, or dealing with internal issues. Why are my koi gasping at the surface? Gasping at the surface can mean low oxygen levels, but it may also indicate gill damage caused by parasites or poor water quality. Always test your water before assuming the cause. What causes lethargy in koi fish? Lethargy—slow movement, drifting, or inactivity—is a common sign of illness. It can be caused by poor water conditions, infections, parasites, or stress. Healthy koi should be alert and responsive. What physical signs should I look for in sick koi? Common physical symptoms include: Ulcers or open sores Redness or inflammation Excess mucus or milky skin Clamped fins Laboured breathing Swelling or bloating Raised scales (pineconing) Erratic swimming or buoyancy issues These usually indicate the problem has progressed and needs immediate attention. What do ulcers or red patches on koi mean? Ulcers and red patches are typically signs of bacterial infection. These often develop after parasites or poor water quality weaken the fish’s immune system. Why are my koi’s fins clamped? Clamped fins (held tight against the body) indicate stress, discomfort, or illness. This is often linked to parasites, poor water quality, or general environmental stress. What causes koi to swim erratically or lose balance? Erratic swimming, rolling, or floating incorrectly usually points to swim bladder issues or severe stress. This needs immediate investigation. What are the most common causes of koi illness? The three main causes are: Parasitic infections (e.g. flukes, costia, whitespot) Poor water quality (ammonia, nitrite, pH instability) Stress/environmental factors (overcrowding, temperature swings, handling) What should I do first if my koi looks unwell? Start with these steps: Test water parameters (ammonia, nitrite, nitrate, pH, KH, temperature) Observe fish behaviour closely Stop feeding if water quality is poor Isolate severely affected fish if needed Investigate parasites (scrape and scope if possible) Avoid using treatments unless you know the cause. Should I quarantine a sick koi? Yes, if one fish is clearly affected. Use a quarantine tank with similar water conditions to reduce stress and allow targeted treatment without affecting the whole pond. Do I need a microscope for koi health? For accurate diagnosis of parasites, yes. Many common parasites are microscopic and cannot be identified visually. Without proper diagnosis, treatment is often guesswork. When should I call a koi specialist? You should seek expert help if: Water quality is good but symptoms persist Multiple fish are affected Symptoms worsen quickly (ulcers, pineconing, weight loss) Treatments are not working You cannot diagnose parasites Can poor water quality really make koi sick? Absolutely. Poor water quality is one of the leading causes of illness. Even clear water can contain harmful ammonia or nitrite. Regular testing is essential. How can I prevent koi from getting sick? Prevention comes down to good pond management: Test water regularly Maintain proper filtration Perform routine water changes (10–20%) Feed high-quality, seasonal food Avoid overfeeding Minimise stress and handling Avoid overcrowding How often should I check my koi? Daily observation—even just 5–10 minutes—can help you spot problems early. The sooner you notice a change, the easier it is to fix. Is it better to treat early or wait? Always act early. Waiting often allows the problem to worsen, making treatment more difficult, expensive, and less effective. Quick Summary Behaviour changes are the first warning signs Water quality is the most common issue Early action prevents serious problems Don’t treat blindly—diagnose first