Hello
You have recieved some excellent advice from Newman about your filter. Turning off the filter is a terrible idea, and will result eventually in the death of your fish. The filter is there not only to provide water movement, but also to keep the tank clean. The way the filter does this is by drawing in the water, cleaning it, polishing it, and sending it back out. The filter itself is providing mechanical filtration by moving the water. But there are also more subtle things going on inside the filter. Every prepared filter comes with a product or surface that collects nitrifying bacteria over time. This helpful bacteria is essential for the health of your filter, and for the health of the tank itself. It helps to neutralize ammonia and nitrites in the aquarium, preventing spikes in these chemicals that could harm your fish. Ammonia and nitrites are the first and second products of aquarium waste. When the fish urinate or poo in the water, most of this is released as ammonia. The ammonia is then broken down by the bacteria into nitrites. The final product of the cycle are nitrates, which are less harmful to the fish than nitrites. The final component in the filter is the chemical filtration, such as carbon. Some people do not use carbon or other chemicals, but the other two are absolutley necessary to keep your tank healthy.
Goldfish are cold water fish and need a minimum of 20 Gallons per fish. Unless you have a very large tank, in the neighbourhood of 40 gallons or more, these fish are best relegated to ponds. Even still, you might find it difficult to find tankmates for them, as most fish do not like the same conditions as goldfish.
The best environment for the crab would be a paludarium, where it would have space to move about both in and out of the water. In a 10 Gallon tank, this would be difficult to achieve if you wanted to have fish, because there is simply not enough space to build up an area of land while at the same time allowing a lower space for the fish to swim in water.
That being said, there are many options for you with a 10 Gallon tank. Sometimes beginners look at the tanks in the fish stores or the pictures that come on the boxes when you buy the tank. I get sad and frustrated by this because most people that work in fish stores, though they are only doing their jobs, are not educated enough to provide detailed information about the set-up of a new tank. It can look appealing to see the tanks in the fish store that are literally busting with colourful and active fish. It must be understood that this is not meant to be the fish's permanent home, and it is designed to look appealing in order to sell the desired product. You simply cannot stuff that many fish into a small tank and expect them to do well. Secondly, there are so many wonderful kinds of fish, and so little space, money, and time. I made the mistake initially with my first tank to get one of this and two of that..., and maybe, one or three of this other thing... Needless to say, it ended up being a virtual aquatic Noah's Ark. This also, is not desirable.
My advice for you at this point, would be to rehome all of what you have except for maybe the snail. Keep him and put a very little fish food in each day to make sure the tank is continuing to cycle. Keep the filter running the way Newman suggests, with the water level up over the area where the water runs out of the filter, to keep noise down. In the meantime, read up on a few fish you find appealing, and get something you really want. There are a lot of things to consider, and it is better to do a little research, and ask questions, like you are doing now.
Here are some great suggestions for fish you could keep in a 10 gallon with a heater:
Male Guppies, swordtails, or platies: they are colourful and easy to care for. I would steer clear of getting any females, because they reproduce like mad, and you will soon have more fry than you can handle.
Dwarf Honey Gouramis: This is a small gourami that likes to be in groups. Five would be an excellent number if this is all you were going to keep.
Small Tetras: there are a bewildering number of species of tetras that would be happy in this home. These also like to be in schools. Odd numbers look best, perhaps five or seven. Glow lights, Neons, and Black Phantom Tetras are all small and not so active that they would need a larger space. I would steer clear of Dawn or Panda Tetras, Gold Tetras, and Silver Tip Tetras, even though they are small, because these are very active and need lots of room.
Harlequin Rasboras, Porkchop Rasboras: Another beautiful small schooling fish, best kept in small odd numbers.
Leopard or Zebra Danios: These are active little fish, but a few would be OK here. Once again, they like to be in schools. Steer clear of the Giant Danios, however. These are large, and extremely active. I once had to rehome a few of these, because they were too active, and were bothering my other fish. The tank was 55 Gallons.
As an extra bonus, to add detail and help clean the tank:
Glass Shrimp or Red Cherry Shrimp. These are interesting to watch and add an extra focus.
Malaysian Trumpet Snails: These help to sift the gravel and will eat any left over fish food. I wouldn't encourage you to have either Pond Snails or Ramshorn Snails, because their numbers will quickly get out of hand. This looks unsightly, and these snails do not sift the gravel like the Malaysian Trumpets. They also eat plants, and if you are planning to have plants, it could prove to be a problem.
Yes, you can get stands for a 10 Gallon tank. They come in many shapes and sizes, and I would suggest you check your local second-hand listings before buying anything new. You might also want to get in contact with your local aquarium society. This will place you in contact with other people who are interested in fishkeeping. You can view fish, and there is usually auctions where you have the opportunity to buy fish and supplies at a fraction of the price you can at pet stores.
I hope some of this has helped, and that I have not overwhelmed you with information. Keeping fish is a very interesting hobby, and can quickly become addictive. If you can only have one tank, you might as well have some fish that really interest you and that you can enjoy for a long time to come.
Take Care
soul-hugger
