What To Do When Your Pond Fish Are Sick

By July 28, 2015 Ponds
What To Do When Your Pond Fish Are Sick

Doesn’t it seem like things only go wrong when you’re least prepared? You come home from work to find your koi or other pond fish floating on their sides. Or on your day off you notice a few fish seem to have developed scales. And somehow that’s always exactly when the pond shop is closed.

Don’t panic!

Even though fish don’t wait until a convenient time to get sick, that doesn’t mean you (or they!) are dead in the water, so to speak.

With a little bit of planning and some quick detective work you can mitigate many common problems on your own, or at least stabilize the environment until you can see a professional for advice.

Prevention Is Your Biggest Ally

Dealing with sick fish is no fun, especially since the health of one can affect the health of all. If you really want to mitigate illness, your best bet is to start before it happens.

That means maintaining a healthy pond ecosystem by ensuring proper water temperature, cultivating beneficial plant growth, mitigating algae problems, feeding fish properly and more.

You might be surprised by how small things can add up to big problems. For example, overfeeding your fish can leave uneaten food to sink to the bottom of the pond where it will not only decay and cause cloudy water but become fodder for algae. That will ultimately upset the balance of your pond and can lead to the proliferation of harmful bacteria, too much ammonia and subsequently many fish diseases.

For more about maintaining water quality, read a recent post we wrote about it here.

Tuck Away A Pond Test Kit

It’s also a good idea to keep a few handy essentials in your garden shed or garage so that if your fish do become sick you’ll have some ammunition to help you work through it.

With a pond test kit you can diagnose many of the most common issues and then take educated action. A test kit will let you measure the amount of ammonia in the water, nitrates and nitrites, dissolved oxygen and more.

Once you’ve tested the water, the results can give you a clue into the problem and possible solution.

For example, if you discover a high ammonia content, you may recognize that you’ve been feeding your fish too much and that has caused excessive fish waste and organic decay. The long term solution would be to modify your feeding schedule to something more appropriate. The short term solution may be to add salt to the water or to do a water change and replace some of the contaminated water with healthy water.

Try A Salt Cure

Ok, maybe you’ve worked diligently to maintain your water quality or maybe that advice is a bit “cart after the horse” right now. Your fish are sick and you need help.

Believe it or not, adding salt to your pond can cure a host of fish problems. Your best bet is to use a sea salt designed specifically for pond use but in a pinch you can actually use non-iodized table salt. Either way, be careful to add only as much as is needed based on your pond volume. And since the table variety doesn’t come with instructions, it wouldn’t hurt to keep some pond salt on hand for when you may need it.

Adding an extra .2-.4% salt by volume can kill common parasites and reduce nitrite toxicity. But be careful – excess salt can harm plants, so you may want to consider removing a sick fish and giving it an individual salt bath instead.

Your best bet is to test the salt level of your water first to be sure it’s not already high.

And as a side note, maintaining an appropriate salt level in your pond can actually strengthen your fish’s immune systems and avoid parasitic infections in the first place!

Change The Water

If your water is looking a little cloudy or you’ve done a test to find it out of balance, one quick fix might be to try changing out the water.

You can swap out up to 25% of the existing water for fresh water and that may just do the trick. First, drain out the old water with a shop vac, pond vacuum or siphon hose.

Then slowly add the new water at the last stage of your filtration system so it can be mixed into the whole volume of the pond. This is important because the new water is likely to be a completely different temperature than the existing water and sudden changes in temperature are harmful to fish.

Beware chlorinated water because excess chlorine can also harm and even kill fish. Chances are your municipal water has some chlorine in it so if you’re using a garden hose be sure not to leave it running too long and let it overfill your pond. Always monitor the process and keep an eye on your fish.

And remember, we’ll test your pond for free, so if you ever suspect a problem, let us know. We can diagnose, treat and even maintain your pond.