| Author: Curtis B Original Date Submitted:7/5/2003 Revised Procedure 7-26-2005 General Overview Skip to "Procedure Part 1" if you do not care why I advise this technique over common advice. When buying new fish from a local fish store, they tend to tell you to float the bag in the water and perhaps to add a little aquarium water into the bag several times. I have found this method to be not very effective at all, hard to accomplish because bag does not want to stay upright and lastly, very stressful to the fish. Furthermore there are situations where this sort of acclimation is just plain unhealthy. So in an effort to keep this article shorter and simpler, I will spell out a way to acclimate fish in a quarantine tank, that will work for all fish, even if you just received them mail order from across the country. Every serious fish keeper should have a small 10 gallon QT tank just for receiving and examining fish for the first month. My method of acclimation is done directly in the tank instead of alternative methods. It may sound a bit complex and difficult, but once you try it once, you will realize that it is not too time consuming. We spend good money on fish, and spending an extra few minutes running some tests instead of floating bags, is well worth your efforts. Acclimating Fish The Scientific Way? Note that fish just shipped through air mail will probably be in water that is high in ammonia, nitrite, fairly cold, low in oxygen and low in pH as well as a whole different chemistry when it comes to Osmoregulation. It really depends on how many hours they were in the bag and how they were packed.This method is meant to address these issues as well as other reasons that hardness can shift between the pet store and your tank. Now you may ask " why are 'total dissolved solids' (TDS) important when it comes to acclimation?" Well, in fact, it may not be a problem at all for saltwater fish keepers because they keep their specific gravity ranges fairly tightly controlled. Freshwater and Brackish is less tightly controlled, so people and places all over the world have all sorts of different "freshwater". Furthermore a local fish stores can keep some fish in light brackish water to curb disease or even have things like Arogonite in their tanks that can cause the TDS to increase dramatically. If you move these fish from that tank, to a tank with much lower TDS, severe damage to the fish can happen which may in fact result in a very quick death. I believe this causes more fish deaths in the first few days after purchase than any other thing except for possible injuries caused by catching fish the wrong way. The TDS change messes with the fishes "Osmoregulatory " system. For a more "In depth" and technical discussion of Osmosis, please see this article. Excretion, Osmosis and Ion Regulation The Information available to the fish keeper seems to be vague and hard to find on how long it takes a fish to readjust it's Osmoregulation system but everyone seems to agree that adding a very small amount of sodium chloride salt is very beneficial to speeding up the transfer of solutes through the gill membrane. This is why you see people say " salt helps reduce stress" . Salt has grown to mythical status with some people, and there are some very important benefits, but it is not a miracle cure for every problem. Note that salt is not really a cure, but only helps speed the process up a bit.. Since you can not really control how fast the fish can re balance it's osmoregulatory system, then I propose you take a different approach that will mitigate potential problems. Your first concern should be the water they are kept inside. Is that "Molly or Platy" kept in a brackish tank with 1.010 specific gravity? (SG) Does that Malawi Cichlid reside in a tank with crushed coral for substrate? Or is it kept in water very similar to yours at home. There are several tests that can be used to find out approximately how much dissolved solids are in your tank water. The same tests should be done on the fish bag water for comparison. There is a simple instrument called a "Hydrometer" that most people think only measures salinity, but what it really measures is the Density or "Specific Gravity" of the water, and since dissolved solids weigh more than pure water, a hydrometer will render a total reading of all total dissolved solids. A hydrometer is pretty hard to use inside a fish bag so you might have to skip this test on bag water. A GH test kit as well as a KH test kit are also nice tools for determining how much of the dissolved solids are carbonate in form and how much is comprised of calcium and magnesium. The actual makeup of the water is less of a concern than what the dissolved solids total or "SG" because osmotic pressure is promoted by the density of the water. If you do get a Hydrometer, make sure you get one that starts at 1.000 Specific gravity. There are many that start higher at about 1.010 specific gravity which would not do much good for freshwater fish. You may also get the seller of the fish to test the water where the fish are coming from and give you the results. If your water has less TDS than where the fish are coming from then you can set up your quarantine tank in advance in order to simulate the water conditions where the fish are coming from. Another way might be to run the tests from a bag sample when you first get your fish, and immediately start adjusting the quarantine tank into the general vicinity or slightly higher in TDS than the sample water using salt, (sodium chloride), calcium chloride and magnesium sulfate ( Epsom Salt) . Once those GH and KH numbers are close you should be very close on the specific gravity. I have no data on how much of a shift in TDS is significant to the fish or how fast they can re regulate. One note of caution. All of these salts that harden water all dissolve and diffuse at different rates depending on the compounds used. Magnesium Sulfate ( Epsom salt) and calcium chloride both dissolve very quickly which is an advantage. If your particular problem is removing TDS from your water rather than adding to it, then investing in bottles of distilled water and adding that in a ratio to your tank that will achieve the proper mix as a quick and effective solution but it is probably not necessary. Fish are far less stressed moving to harder water and it has never been reported to be fatal. There should be little you need to do except add a little salt to help them adjust. Procedure Part 1 So putting information above into action, here is a step by step method that I have had great success with. 1. Measure GH, KH, and SG in the bag 2. Adjust QT tank to nearly match or exceed the GH , KH and SG ( GH can be increased using calcium carbonate and Epsom salt, Baking soda will increase KH, and SG will get higher with any dissolved solid like sodium, potassium and the components in GH and KH) 3. Add a little aquarium or sea salt to the QT tank ( 1 tsp per ten gallons is fine) Potassium Chloride also works for the same purpose. 4. Empty the fish from the bag into a net 5. Place the netted fish directly into the QT tank. Notice that I worry very little about temperature and pH. Honestly I have had no problems with acclimating them with temperature and pH shifts. I know this is against nearly every other persons advice, but this is my personal observation over the years. 5. Turn light off? I think this is probably silly advice since the fish can see outside of the tank during the day easier with the light off and you can not observe them very well. Leave the light on and enjoy your new fish but try not to walk by the tank too much. 6. Observe the fish for signs of stress about 1 hour after adding to the tank . If they are still stressed you may want to increase the hardness and salinity a bit more. Noticeable stress symptoms are a lack of appetite and breathing heavy Procedure Part 2 Acclimation to YOUR water over time. Take your time. Every week do a couple of very small partial water changes with your normal tap water. Eventually the tank will equalize with your tap water, and the fish will be ready to live in your natural tap water. Some very species specific studies in food fish show that most fish can change their regulatory system drastically within 48 hours or so, but I would advise stretching it out to at least a week. Since I quarantine my fish for a month or more, I will stretch the acclimation period out that long as well. I really don't work to hard at it, but I do write down what I have done directly on the glass of the tank with a "Sharpe" pen to remind me where I am at. Take your time and enjoy your new fishy friends. Here is an example of a good acclimation technique over time. 1st week - do a couple of small <10% partial water changes. you can add a little salt, but no need to increase the GH and KH levels or add distilled water at all since you want them to adjust to your water. Of course use Dechlorinator. 2nd week. You can increase the partial water change amount to 20%. Use less salt. 3rd week. Just do a normal partial water change of about 33.3% not adding anything except your normal Dechlorinator. 4th week. By this time the water from your tap and the tank should be very close to being equalized and normal water change routine can continue without worry. | 
