Fish Health & Care

Below is an article I came across in the July 2003 edition of The Waterlog, a monthly newsletter from the Minnesota Water Garden Society. I am always looking for new and helpful information to make your pond keeping experience as enjoyable & rewarding as it can be. I myself learned many new and helpful tips from the article below and felt it important to share these with fellow fish owners. I have never claimed to be a fish vet & believe in keeping things simple regarding pond keeping, this article will answer many of the questions you may have about water quality and your fishes health in addition to providing information about fish first aid, something hopefully never needed.  Many variables can and do take place from pond to pond, site to site, this article is intended to supply some ideas and tips regarding fish and their health, although we cannot guarantee it.

Fish Health and Care Article By Sue Emerick

Now that you’ve gotten your pond and fish through the winter, what’s next? Time to carefully observe your pond and fish. So now you have breathed a sigh of relief that your fish have made it through our last winter, well hold your breath a little longer. We are not out of the woods just yet. The second most vulnerable time of the year for your pond and fish is spring!  As I write this, spring has finally arrived and warmer weather is just around the corner.  By now you have cleaned the pond, fired up the circulation systems and filters, and by now the filters should be firmly established.  Fish have been returned to their summer home after their long winter sleep.  The pond is alive once again and so are the parasites and bacteria that can cause problems for the ponds and the fish.  Fish coming out of their deep winter sleep are stressed and very vulnerable to illnesses.  But the good news is, there is much the pond keeper can do to diminish problems during the Spring and through-out the summer months.  I want to offer a few tips that might help you; your pond and your fish get through the typical spring time problems and help with some summer maintenance topics that may ward off problems during the summer months.

It is very important you keep in mind that water temperatures in the spring tend to hover around 50-60 degrees. While there are cold water parasites that can bring havoc to the fish, at these higher water temperatures most other parasites are thriving and the bacteria (good and bad) is growing in the pond environment.  How ever, your fish’s immune system is not yet up to withstanding these elements in the pond and the fish are still rebuilding their slime coat.  During spring months you might start to experience fish illnesses in the pond.  This is the time that they are least prepared to fight off the stresses, parasites and bacteria existent in the pond.

Early in spring is the time when most pond keepers drain and clean their ponds for the new pond season. If you have rocks and pebbles on the pond floor, I would recommend a “power wash” cleaning. If you do not have rocks on the pond floor, simply drain the pond and remove any winter debris that might have accumulated.  It is important to start the season with a pond that has most of the fallen and trapped debris removed from the pond. Try not to remove any algae growth that your pond has developed unless it is excessive.  This is also a great time to inspect your plumbing and the “under the water level” condition of your liner. A good cleanup of the pond is necessary; however, you don’t need to clean it as you would clean your house.  A mature pond has certain natural conditions that you don’t want to disturb any more than necessary. When you refill the pond in the spring, even though you may not have fish in the pond, use Amquel (or a like product) if you use city tap water. Chlorine will kill most, if not all, of the bacteria that remains in your pond and in your filter and you want to protect that bacteria colony as much as you can.  For those that must power wash their ponds because of pebbles or rocks on the pond floor, you will more than likely see an algae bloom and need to allow your filter more time to get established.  This is normal and should be allowed to settle out (cycle) naturally. If you placed barley straw in the pond early this can be a great help during this time.

There are several additional things you can do to help your pond and fish get through this touchy time. Replace all your test kits. It is important for accurate testing to start each season with fresh tests kits. The test that should be preformed on a regular basis (once a week) are: a. pH (high pH 8.0-9.0) in our location is normal and will not substantially effect your fish health, but can effect plants. b. kH (100ppm- higher) is common in our area and will not effect fish health substantially. c. Ammonia –should be at zero d. Nitrite –should be at zero (nitrate if you see problems with plants)

When the filter is first established in the spring and you have fish in the pond it is essential that you not only watch the ammonia and nitrite levels in the pond, but also, you should monitor the critical kH (carbonates-buffering) levels in the pond. As the biological filter is getting established and is bringing the ammonia and nitrites under control, the process will consume tremendous amounts of carbonates from the water.  These carbonates must be replaced either from the natural makeup of the pond or from added elements.  I maintain crushed oyster shells in my system (in the water flow) all year round. The carbonate balance of the water takes from the shells what it needs when it needs it.

Signs of problems with fish? Test daily. Once you have built a relationship with your pond (gotten to know your pond) these tests can be preformed less often (Except the kH test) and then more often when signs of fish distress are evident. kH should always be monitored weekly.  It is also a good idea to also test your source water so you know what you are adding to your pond.  If you do not have rocks on the pond floor, I would recommend getting your pumps and filters running as early as possible BEFORE you clean your pond.  There are viable bacteria even in a winter pond which will enable your biological filter with a “kick start” for the season. Allow the system to run at least 3 weeks before cleaning the pond.  The bacteria already existing in the pond will naturally “seed” your external filter and you will experience little, if any, ammonia problems and you will save on the cost of bacteria.  If you use UV lights, do not start them until your filtration is established. UV lights kill everything that passes by the light including your “good” bacteria. Note: I accidentally discovered that the bacteria were still active after a long winter just this season. I couldn’t get out to clean my pond, but I wanted to get my “system” up and running. So I hooked up my pumps and simply let the system run for about 3 weeks. After 3 weeks I added non-sudsy ammonia to alert my filters to start making bacteria. Much to my surprise, the following day I had no ammonia reading. I didn’t believe it so I added double the bottled ammonia the following day. I allowed the pond to circulate for about 2 hours. I pulled a bucket of pond water aside and then took an ammonia reading from both the pond and the bucket.  Both read .05 after circulating for 2 hours so I know I had a measurable ammonia level in both the pond and the bucket water. The following day I tested the pond and bucket water once again. The pond level for ammonia was zero and the tested bucket water was still at .05. More surprising to me was that I had a zero reading for nitrites also! That told me my filters were doing what they needed to do.  Then I drained and gently cleaned my ponds, refilled and, after 4 days, started adding fish over the next several weeks so I wouldn’t overload my newly established filters. The bacteria in your filter will increase slowly as the fish load increases. It is important to note that in cooler temperatures, the bacteria in your filter grows more slowly and below 45 degrees they are essentially non-existent.  I strongly suggest that you start to do regular water changes once the pond has been running with fish in it. This should be done routinely throughout the season. Approximately 15% - 20% of the water should be replaced every 2-3 weeks. This will reduce parasite populations in the pond, reduce background pollutants, any remaining ammonia, nitrite and nitrate levels in the pond and renew the carbonates (kH) levels in the pond.  It is imperative that carbonates be replaced regularly during the season to ensure your ph remains stable and that your filtration system remains viable. Without a level of at least 80 ppm (preferably 100ppm) kH level in your pond you are risking major problems with fish and filtration.

Lymnozyme (now known as KoiZyme) is a product I started using last spring. It is a product that rids or greatly reduces the amount of harmful bacteria in the pond that can cause bacterial infections in your fish. I highly recommend using it especially in the spring. It is expensive, but I have had great success healing ulcers in only a few days after the second dose. I use it routinely now in the spring and then again if I start seeing an outbreak of bacterial infections later in the spring. Consider adding salt to the pond to a level of .1% (considered a maintenance dose.) This would be 1 pound of salt to 100 gallons of water. If, when testing your pond for ammonia or nitrites, you find elevated levels of either, increase the salt level to .2% (2 pounds per 100 gallons) this will protect your fish from gill burn caused by elevated nitrite levels in the pond. Adding salt at a maintenance level is always optional. Salting in the spring also helps build a slime coat on the fish.

Oxygen levels in the pond water are higher in the spring with its lower water temperatures. As water temperatures increase, the oxygen carrying ability of the water decreases. As summer approaches with its higher temperatures, you must ensure that you can maintain adequate oxygen levels in the pond. Adding air stones will accomplish a variety of things at any time during the season: a. Increase oxygen saturation in the pond water, which is essential if you are keeping Koi. b. Filtration also is at its maximum when high levels of oxygen are present in the water. c. The bacteria in your filter require oxygen to remain viable. d. Increased oxygen infusion helps to “gas off” nitrogen and carbon dioxide from the water. e. Increase water circulation on or near the pond floor, which will help keep debris suspended in the pond water so your mechanical filters can easily remove them from the water. This will greatly decrease the amount of sediment that settles to the pond floor, which will reduce algae growth and help reduce spring pond cleaning. Note: Adding a good air stone and several large air stones will increase the health of the pond’s environment and water quality. This is such a simple addition for such a great return and probably the most overlooked addition to any pond. No special upgrades are needed to the pond; not a great expense. The fish and the pond will be much healthier for it. Large air stones are available online through Aquatic Eco-Systems, Inc. PN9730. I recently purchased one of these. I found this unit provides a “big bang for my buck” and it will amply handle 8 large air stones at deep levels. The cost was very reasonable at around $80.00 plus shipping, considering what air pumps can cost, and compared in cost to a “Tetra Deep Water” pump, which will only handle 2 large stones at 2 feet deep. This pump will handle the outside elements also. This unit is probably the best buy I’ve made since I found KoiZyme.

  First Aid! Ok, so now, all is going well. You’ve done all the maintenance stuff everyone keeps telling you to do, but then suddenly you have fish in trouble. What do you do? You don’t know what is wrong, but the fish are not acting right or they may have developed ulcers (sores). Behavior is one of the first signs of fish in trouble. The fish may have isolated himself away from the group, stopped eating, may be gasping at the surface or laying on the pond floor or may be acting and eating normally, but you notice some sort of new odd coloration on the fish or an open sore. Behavior indications without physical sores can mean water quality or parasite problems. Test your water so you see what is going on. If all that seems normal, then add salt to .3% slowly over several days and hold it there for two weeks. (1 pound per 100 gallons for 3 days = 3 pounds per 100 gallons or .3%) You should remove water lilies, floaters and most plants from the pond as salt at this level will harm most. Increase circulation (air) to the pond water if you haven’t earlier in the spring. Watch to see if this improves the condition of the fish. If any test reading is not within “normal” ranges, do water changes (25% every other day) first before adding salt. Either or both of these remedies are most likely to help most behavior related illness problems and the salt level will handle many parasites. 

Ulcers or sores on the fish are something else all together. Water quality and possibly parasite problem is something that should be looked into. However if it is a bacterial infection it must be taken care of immediately. There are several methods that can be used. A good “First Aid” kit for the pond would include the following; 1. Quarantine/hospital tank always running and ready. 2. Hydrogen peroxide –topical “wash” apply daily (keep away from eyes and gills). 3. Neosporin (without the pain additives) –Dry area gently-rub ointment on sore; apply daily. 4. Debride ointment (purchased online – very effective but expensive) –topical treatment-dry surface and rub on. 5. Iodine – topical treatment- dab gently on ulcers; hold fish out of water for about 2-3 minutes; keep away from eyes and gills; apply daily; return to holding tank. 6. Morton Solar Salt -40 lb bag. 7. Clove Oil (use to anesthetize IF NECESSARY; 5-7 drops/one gallon of water –stir-place fish in water and watch for about 3-5 minutes. You will be able to handle the fish for treatment). Once the fish is treated, replace fish in pond or holding tank. He will recuperate within a few minutes. You can also use this mixture if the need ever arises that you must put a fish down. Put the fish to sleep and then place in water in a bag and place in the freezer. This is the most humane way to do this. 8. Cotton balls/Q-Tips.

Optional additions to the first aid kit: 1. If it becomes necessary to heal ulcers, you can use Baytril or Azactam injectible antibiotics, insulin syringes (dosages available upon request). 2. KoiZyme –maintenance dose product which competes with the unwanted bacteria in the pond. Eliminates or greatly reduces the unwanted bacterial population. Does not eliminate parasites. Debride and KoiZyme can be purchased through PondRx, an online web site supported by Dr. Johnson, KoiVet. You can also try to establish a relationship with your local vet. I am allowed to purchase directly from my vet a limited amount of the antibiotics I sometimes require. He has worked with me on many occasions with my other critters and my fish, although fish are not his main area of practice. He is also aware of what I am using these products for.

I am hopeful that no one has a need for any “first aid” this season, but in the event you find yourself in a situation where you need to intervene in the health of your fish, I hope that this basic information will be helpful. The information provided here is not by any means as complete as it might be if I had the entire print space of the Waterlog available to me, but it is a good start. Please also remember that I am not a vet. My knowledge is through my personal experiences and what has worked for me over the years. Happy Ponding.

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