Goldfish

That depends entirely on the type of fish that are in the tank. If you have tropical fish, temperatures ranging from 75-82 degrees Fahrenheit is about perfect. Freshwater fish are typically more forgiving of temperature differences than saltwater or oceanic fish tend to be. If you have common gold fish or other non tropical fresh water fish then room temperature or about 64-76 degrees is about perfect.
Between 75 and 80 f

Making the assumptions that these measurements are in inches, and that the fish tank is a perfect cuboid, the volume of the fish tank is 49 x 19 x 21 = 19,511 cubic inches.

Rounded to two decimal places, this is equal to 70.47 gallons.

Yes. Several species of aquarium suckerfish can be quite aggressive, mostly as the age, and can grow to be pretty large. The Otocinclus catfish is the most peaceful, and stays small, so is a god choice for a small aquarium. But be careful, they are fragile in unbalanced tanks and must have algae to keep fed.

Nothing. The smallest size that's OK for a fish is 5 gallons and that's only for a betta. Any other fish need much more room. In a one gallon, you can put plants and some snails, but not much more.

well, an educated guess would be that the latter would chase the corpse of the dead goldfish around until it realized that the goldfish its chasing is acually really just a dead corpse. then, once this fact was realized, the (alive) goldfish would most likely eat the dead goldfish, and that wouldn't be good now would it? so you should probably, most likely try to maybe keep all of your goldfish alive and swimming, not dead and chasing eachothers dead bodies all around.

Trout can survive if the temperature is warm enough or the water is deep enough to prevent the water from freezing completely. A mountain trout would be a good choice;however, the same conditions would apply.

Your poisoned water (Lack of care) is killing/has killed your goldfish. You really must follow the basic rules of sucessfull fishkeeping if you want to keep fish succesfully. The basic rules are . :- 1 inch of fish must have at least 1 gallon of water.(A goldfish is a 10 inch fish and so needs at least 10 gallons of water.) :- Every tank must have a permanently running 'cycled' filter. :- Every tank must have at least 50% of its water replaced every week.

== If it is Algea you should empty the fish tank and put the fish into a bucket. Then you should clean the tank after that i would recommend buying sucker fish and a under gravel filter as i had this problem!! if it is not this i recommend going to a fish store and asking them about it!!!

If it's a whitish cloud, the bowl has accumulated too much ammonia. (Which comes from, well, fish poo)

Change out a little less than half the water with clean water at the same temperature, SOON.

Goldfish are egg laying fish, so they do not get pregnant.

Unless there is a male in your tank, the female either may not release her eggs at all & simply reabsorb them, or if there is a male, and he chases the female to convince her to release her eggs, some of those eggs may become fertilized.

Goldfish love worms and they are definitely one of the finest foods you can give them.
They're also partial to mosquito larvae if you can find any in summer. Make sure you wash the worms first though, and if the fish don't eat them remove them quickly otherwise they'll rot and affect the water quality.

The easiest way to tell the difference is that the males may get what are called breeding stars on their gill plates during breeding season. The breeding stars look like small white bumps.
This is not always the case though, and sometimes the only way you know is by seeing the female drop eggs, or the male fertilizing the eggs.

Typically a goldfish will lose scales if it's bumped into something in the tank hard enough to tear scales; take a closer look at your decorations and remove anything with sharp edges.
If there are many scales missing in multiple areas on the body, or you have nothing that could cause the loss in the tank for decorations, then it's possible that the fish has a parasite that you will need to treat.

Unless the baby goldfish is fry size which means it cannot eat regular sized food as of yet (flakes or pellets) then yes, you can put small goldfish with large goldfish.

While they may not necessarily eat the baby, there could be a concern with fin nipping, but as long as the smaller fish have a place to hide and feel safe, there shouldn't be an issue.

I have had so many debates on this issue. I have personally watched goldfish nip at fins of other goldfish, heads of orandas and even the tail of a freshwater stingray (don't ask). So yes, they are nippers.

Water changes can really vary from the size of your tank to the amount of fish you have in it.New tanks will need more water changes than well established tanks because they will have higher ammonia and nitrite levels which are more toxic than the toxins (nitrate) found in cycled tanks.In the first four-six weeks of having a newly set up tank do partial water changes whenever testing for nitrite and ammonia reveals high ammounts.Do a 10-25% water changes at a time and when your aquarium is over 6 weeks do water changes of about 25% percent every one-two weeks and when needed(that is when testing reveals high nitrate levels).

i had same problem i was told to add water conditioner from pet shop it helps remove chlorine from tap water and had aloe vera which helps protect scales. However what is most likely your problem, because goldfish can't survive in chlorine for as long as a week, is that you have your fish in too small of a bowl/tank. Having your fish in to small of a bowl/tank would result in a build up of ammonia (which is produced by your fish eating,pooping, and breathing). This build-up would damage your fish's gills and cause it to die. What could also be your problem is that you don't have enough aeration (if you saw your fish gasping for breath at the surface before it died than you don't have enough aeration.) An easy way to fix this problem is to purchase and air pump, bubble curtain, or an aerator at your local pet shop. One other possible cause for your goldfish's death is that it was just plain out unhealthy. If left untreated usually the fish would die from its ailment within a week- two weeks . Next time you get a goldfish put it in a larger container ( goldfish thrive in tanks of at least ten gallons ) and use an aerator. You should be fine as long as you use a conditioner and have a strong filter.

If your fish has turned white as opposed to become covered in white fungussy stuff, you can assume that is simply the fish developing its adult colouring. Goldfish start off grey/silver and as they grow up their adult/mature colours develop. If it is white fungussy stuff on the fish you need to do some seroius cleaning of the tank and replace the water a few times. You probably would be wise to strip the tank down and scrub everything. There are medications available at pet shops for fungus.

usually yes goldfish also swim along the surface of the water to get the predators attention then they turn and swim as fast as their little tail will carry them! then they swim as deep into the pond or lake or stream or bowl or tank as they can go!