Why do our goldfish keep dying when we change the water?

Question

We just lost 2 more goldfish that were thriving in our 10 gallon tank. This is the 3rd batch we've lost after changing water. The others may have been due to temperature issues, but we were very careful this time. When we changed the water, we made sure the temperature was the same but within a few minutes they were floating. They were doing so good and growing until we changed the water. We have city water with a water softener. Do we dare try this again?

Answer 1

Goldfish prefer moderately hard water (5° to 20° dH). Using the softened water is problematic and will weaken the fish leaving them susceptible to disease. You should also treat the tap water with a conditioner that will neutralize chlorine and chloramine. The softener won't remove or neutralize these compounds which are toxic to fish.

Another problem you face is that a 10 gallon tank is the very bare minimum size recommended for a single fancy goldfish. Placing two fancy goldfish in that 10 gallon tank will result in far too much ammonia for your fish to remain healthy. Goldfish are fairly hardy and forgive many "mistakes", but a buildup of ammonia will kill them quickly and ammonia will build up very quickly in a 10 gallon tank with 2 goldfish.

You should be doing partial water changes of 25-33% only each week. It's never a good idea to replace all the water in a tank as it will harm the tanks biological filtration.

Try again, but only get a single fancy goldfish. Also, make sure you use a good tap water treatment such as API Stress Coat. Also, see about finding a way to "tap" into your water source before it gets to your softner. (I'd recommend a fantail, black moor, ryunkin or oranda)

Note: I personally don't recommend reverse osmosis water for goldfish. R/O water generally has a pH around 6.0 which is too acidic for goldfish. Goldfish will withstand a wide range of pH, but a stable 6.5-8.0 range is highly recommended.

Good Luck!

Answer 2

You have some good advice here already -

1) need for a larger tank (eventually, if the fish are small, 1-2 inches this shouldn't have caused their immediate deaths, but as adults, you'll need 10-20 gallons PER FISH depedning on the variety and adult size (some can easily get 10-18 inches in length)

2) frequency and amount of water changes - if you have them in a new tank (less than 2 months old for that group of fish), there aren't enough bacteria built up to convert the toxic products of their wastes (ammonia and nitrite) to the less harmful nitrate. You should be changing 10-15% twice a week to 25-30% once a week - it also helps if you have a test kit, or you take water samples to your pet store to have them test for these chemicals - ammonia and nitrite should be kept below 0.5 (0 is ideal but you only get this after the tank has cycled) and nitrate should be under 40 ppm. Use a gravel vacuum to remove wastes from the gravel so they don't decompose and add more to the ammonia-nitrates - just dipping out water isn't enough.

3) equalizing the temperature - try to get the new water similar to the temperature of the old water - again, if you do partial water changes, and difference will be minimized over doing a large water change.

4) using a water conditioner - this removes chlorine and/or chloramine. I'd do a quick call to your water company to be sure which chemicals are being used to treat your water. It used to be that all companies used chlorine, but many are switching to chloramine, which stays in the water longer and can't be removed by letting water sit for a day (this is a good way to equalize the temperature as well!- just get your water ready the day before you plan a change). You also need to use the right conditioner to remove it - if you only use one for chlorine or one that "breaks the chloramine bond", these will break up the chloramine molecule into its components of chlorine and ammonia - both of which are toxic to fish!

5) If you clean the inside of the tank when you're doing water changes, use a sponge/scraper made for aquarium use! Ones you buy at dollar stores and whatever "Marts" often contain cleansers that can kill your fish - they may be cheaper, but they're not a great aquarium product.

6) Don't change out your filter pads or rinse them under tapwater - this is one of the places the "good" bacteria live. Instead, squeeze them out in a container of tank water or dechlorinated water (the chlorine kills them) and reuse the pad - the bacteria stick to the surfaces, and you can add most back to the tank. Companies that make these tell you to change them, but there's no reason (other than giving them more of your money) to not keep reusing them until they're falling apart and no longer "filter" the water.

Answer 3

How long after the change did they die?

If it was soon after, they died of shock from either toxins or temperature. If your water is chlorinated, that will kill fish. You should let water sit out overnight before adding it; that will allow the chlorine to evaporate.

If it was a day after, they probably died from the ammonia spike. There is a delicate balance of toxins in an aquarium. Fish produce ammonia, which could kill them. However, it is changed into nitrite by some helpful bacteria. This could also kill them, but yet another bacteria changes it into nitrate. Nitrate is toxic, but not as toxic as the first two. It can build up until the next water change.

When you do a full water change, you remove all those helpful bacteria. Therefore, it's better to do small water changes. Most people recommend 10-20% every week or every other week, depending on your tank's requirements. Additionally, a small change means temperature is less of a concern.

You should go read up on the nitrification cycle in aquariums, and you should buy a simple test kit to test your water. I recommend the dip strips, since they're easy to use.

Do try your aquarium again, but make sure the first fish you put in are feeder guppies. Expect them to die within a couple days, though a few may survive. You could also use snails or even do a "fishless cycle" by adding a few drops of ammonia. Test the water periodically to determine when cycling is complete and the water is safe again. When the cycle has finished, it's safe to add your new fish. Now only do little water changes, and your fish will live a long life. :)

Answer 4

First off 2 goldfish would be the maximum number that should be living in a 10 gallon tank. They are messy fish and need more space than tropicals.

Secondly, are you running a filter system or just changing out all the water when it needs cleaned? With a filter system you shouldn't be changing more than 10% of the water weekly. Your water shouldn't be coming from a water softener because they use salt to soften the water and the goldfish won't like that. Bottled water isn't good either but would be a better choice. Water from that tap either needs to be treated with a dechlorinator or left to sit in an open top container for 24 hours to allow the chlorine to evaporate.

Goldfish prefer cool water so unless you have real temperature extremes that shouldn't be an issue. Mine love it when I do the water changes and dump a bucket of cold water in!

Answer 5

Do you use a water dechlorinator of any kind to treat the tap water that goes into your tank?

If not, this is your reason. Fish and other aquatic life cannot tolerate chloramine (sp?) of any type and the other additives to tap water makes it even harder on them.

Do you have a fish store reasonably close that sells RO water (reverse osmosis)? If so, use that water next time. Not only is it cleaner and healthier for the fish, it contains a much lower amount of phosphates for nuisance algae to feed on (less time cleaning the glass, more time watching your beautiful pets). This is typically $4-6 for 5 gallons. Should last a month or so for your needs.

If you were using a water treatment of some type, there are many things that could go into the issues here.

How large of a water change are you doing?

For the cycle, please don't use fish. Just go to your local grocery store and buy a raw, frozen cocktail shrimp or two and use that to introduce ammonia. No fish die in the process and its cheaper.

Answer 6

Have you kept the fish in the bag you brought him/her home in and put fish with the bag and all in the fish tank?Tempeture is very important ragarding fish..If the tempature of the water in the fish home you took out while cleaning the tank or even the fish you just purchased is not as close as possible to the same tempeture in the tank . The fish will die of shock. Your water tempeture may be the issue.You have brought home new fish and want to add them to your tank.Do not just pour them right in!You need to let the bag with the fish float in the tank bacause the water is probably much colder and or completly different.You need to acclimate the fish to there new home.If your doing a complete makeover?..Then it's a new home..Or the "holding jar ect.That you are using.You need to put that into the fish tank(let it float)For about twenty minutes or more or less depending on how much a tempeture change . Plus I hope the water in which you stored them is originally from the old water.You will need to add it.You should be using the water from the first tank!It should not be all that dirty!The best way to clean your tank is not an whole overhaul(unless you could not help it ..But with a syphone (suction hose)Only a quarter or less of the whole tank water should be removed after you vacuum the bottom . A good pet fish aquaurium store should gladly tell you how if you asked.If you find yourself strapped for time keeping the tank clean.You should invest in a good bottom tank perpectual filter and air supply pump .You will still need to vacuum the bottom,it cost pennies to run,clean this atleast every two weeks.You STILL need to clean this and add new filter filler to the filter and use charcoal\And a clean sponge handle to just simply wipe the insides of the tank sides and residue.I had gold fish for many years!They are my absalute favorite fish. Don't use soap of any kind or ornaments that are artificial.Gold fish love a marble bottom,lots of stores ,pet stores,craft stores have good clean all glass marbles for sale inexpensive.Goldfish are capable of being bred using marbles for the tank bed.They are carnivores and will eat their own eggs and frie if you were trying to breed them.That is why you use marbles.The eggs fall into the marbles where the adults cannot reach them. But yet still need to be seperated after they are hatched.The professionals they use mesh or netting for.But a good healthy supply of seaweed,available at any pet store and (not expensive) is a must! For all fish!Regarless if you have no intention on breeding them.You want to know another thing!This is from my own personel experience...Get yourself a clean "real"clam shell!If you eat clams you can use one of these shells!Just clean it and boil it for five minutes.It will add all those neccesary nutriants you fish will thrive on over the years . Yes I said years ..I have had the same fish .Goldfish ,guppies,ect for years!!I hope this helps you in any way.

Answer 7

Tap water is chlorinated and contains trace chemicals - you can buy anti-chlorination treatment agent from petstores which sell fish or aquarium products - a few mililitres in every litre of tank water.

Answer 8

you are obviously not adding water conditioner to the water before you add it, heavy metals in tap water kill aquarium fish, water softener will do no good, you need to chemically get rid of heavy metals and cholrine in tap water. good luck.

Answer 9

it's the water softener turn it off ,you use salt .it will kill them .an the water should not be too cold.

Answer 10

test the water ect