Why would one goldfish lie motionless most of time whilst rest swim around? Is it a social outcast?

If you have different varieties of goldfish, make sure they are compatible. The slower fancy varieties might get stressed out by faster ones like comets. Yes, they might feel like outcasts and keep to themselves. Some goldfish might even get aggressive with another and in that case you need to one that is being badgered to another tank.

Why are all goldfish so lifeless and tend to stay at bottom of tank most of time, like they are very tired?

If they aren’t swimming as they usually do, something is definitely bothering them.

If you tank is brand new and goldfish are having a problem because tank has not been cycled. Wait a while and watch. Make sure you cycle tank before you put them in because a new tank cannot deal with ammonia that goldfish produce.

If you tank is an old one and goldfish are suddenly more still than usual it could be that toxicity of water is bothering them. So change water. When your goldfish seem inactive, you must check water for nitrites and pH level.

If you would like to find answers to more Goldfish related questions such as - What is reason why some Goldfish attack eachother? or, What can I do to save my Goldfish from dying when suddenly it turns on its side? - Please visit my site to find answers these questions plus a great deal more information relevant to everything Goldfish. Click here to visit.

* Remove algae on surface of tank with an algae scraper before you siphon out water.

* As name suggests you need to remove 10 to 15% of water from your aquarium.

* There is no need to remove your fish to a separate container.

* As you remove water use siphon to remove messy deposits in gravel.

* In case you have an under gravel filter, then you would have to clean gravel during weekly water changes.

* Do not take out all ornaments and decorations and scrub them clean because you might destroy some of much-needed beneficial bacteria that act as natural biological filter.

* You can clean filters during weekly water change but do not change all cartridges, sponges, carbon packets, etc., as this might remove all good bacteria and harm your goldfish in long run.

* Also remember to rinse any new filter media in cool running water before introducing it to system.

* Once you have siphoned out 10-15% of water and most of dirt and alga, it’s time to replace amount of water you removed with fresh, dechlorinated tap water which has been left at room temperature over night, in container free of soap residue.

* Use a siphon to transfer fresh water into tank as this would be a gentle way to put water back in and it won’t disturb plants and gravel. You would also spill a lot less!

* Do make sure that fresh water is of somewhat same temperature as water in tank. You cannot just dunk in cold water because Goldfish are not tropical fish. Do remember to leave enough space between top of water and tank hood so that your goldfish get enough oxygen to breathe in.

What not to do:

* If you see that level in your aquarium has gone down, do not simply add water to make it level again. This is harmful, as you are not getting rid of impurities in water. You are just adding water without removing dirt and thus making water harder and more difficult for goldfish to live in. So don’t add water to top off tank, do a partial water change.

* Never add water directly from tap. Please keep a separate container only for aquarium use and leave water overnight so that harmful chemicals and chlorine evaporate.

* Please do not skip weekly water changes because if you do not partially change water, you are allowing build up of waste products like Nitrate that are not removed by filter, and contribute to growth of algae.