New and discouraged...

have you cycled the tank? also, be prepared: almost everyone on this site will tell you that 10 gallons is too small for any goldfish. they are notorious for producing a lot of waste, not just poop, but ammonia.

read your post again. you have not cycled. read this article before getting any more fish!
http://www.aquariacentral.com/forums/showthread.php?t=64301

I am also sorry to say that goldfish need atleast 30 gallons per fish to live properly.

some water changes would help out too, about 30% weekly and 50% biweekly ought to work

clean tank, clean everything, new filter media, hmm are you dechlorinating your tap water just out of curiosity? when you add fish do you float the bag so that the temp or the bag can become the same temp as the tank this is usually 15minutes, and then you should get an ice cream pale, place a fish net over it and dump the contents into the net and then release the fish into the tank via using the net, this helps avoid dumping that pet store water into your tank.

if you can try getting the fish from a different store. and if that happens you could look on aquarium central for instruction on how to treat the tank with salt.

Exactly..

With the tank not being cycled you're subjecting your fish to ammonia and nitrite poisoning. The bad water quality is the reason for the cottony growth.

If all you have is the 10 gallon I'd look for other fish then goldies as they need alot more gallons per fish.

Read the cycle article, if you have any questions post them and we'll walk you through it.

If you know anyone with a tank you could ask for some of their filter media and shorten the cycle.

So what you need to do is:

1. get the tank cycled
2. While cycling, research some fish you'd like
3. Ask us if what you're wanting will work so you don't overstock the tank.

I agree that goldfish do need a bigger tank, but that isn't the problem your having right now. Something to consider though for you in the future maybe(a bigger tank)

Here's some tips that may help you out.

- Clean everything: the tank, gravel, decorations, filter, buy a new cartridge for the filter.

- Set the tank back up: If you have "city water" make sure you dechlorinate it. Let the tank cycle before adding fish. If you have "well-Water" test it. See what it's like straight from the tap. I have well water and it's a little hard but I have never had problems with my fish in it. Most pet stores can test your water for you.

- When the tank is cycled and your going to add your fish float the bag first to let the temperature equalize. Next either scoop the fish out of the bag(you'll probably need someone to help with that). Or as said, dump the fish into an ice cream pale/small bucket and scoop 'em out of there. You don't want the store's water in your tank. Most store's almost always have some sort of disease. Better to play safe than sorry.

- Once your fish are in observe them for the next few days. If you see anything develop treat it as soon as you can. The earlier you catch things the better.

- Goldfish don't need a heater, if you decide to get a different type of fish you'll need a heater. Goldfish also should have a filter for double or triple the size of the aquarium(so I have read). You may be better off buying a heater and trying a fish like barbs, platies, mollies, gourami's. Small fish that are generally good "entry" fish.

Hope this helps and whatever you decide, try and keep at it. Once you have a tank up and running it's a real pleasure to watch your fish.

I pretty much agree with what everyone has said in regards to cycling and the tank being too small for a goldfish. But now, I'd like to mention that "algae eater". Can you tell us what it looked like? If it was small and greyish/black, it's a pleco... a no no for a goldfish tank, I'll tell you why after my next guess. My next guess is it would be a chinese algae eater. These two are the most common "algae eaters" sold from the LFS to unsuspecting/new fish hobbyists. They are most often sold in error. The first reason is the pleco gets too big for the tank, can get from 18 to 24 inches... the chinese algae eater will be fine for a while until it matures and begins attacking. They get pretty aggressive with age, especially in tight quarters such as this. These 2 bottom feeders are also tropical fish and need warmer waters than goldfish as well as a different diet.

Unless you are just incredibly bent on having goldfish, get a heater and go tropical (freshwater warm water fish). I think it is easier than dealing w/goldfish waste and ammonia production as stated. I used to have a couple of goldfish when I was younger and they were a mess to take care of.

For a 10 gallon some good tropicals to look into/research might be: some species of tetra, some species of rasboras, livebearers- (I don't like livebearers, but some folks do) some people keep danios successfuly in a 10 gallon. I would advise starting your cycle, then visiting the fish store and looking in the tanks and make a list of the fish you see that you like. Then, take your list home and research the fish on the net and rule out those that won't work, etc. Sometimes fish aren't appropriately labeled in store- so you gotta be careful. and as you have learned, some employees (not all) don't know anything about fish. While it cycles, you can plan what kind of fish you want

Post and let us know if you would consider going tropical as opposed to goldies so that folks can post you some more ideas. Don't get discouraged, I know I had a rocky start in the beginning ...