The one fish per gallon is NOT used any more. As many mentioned each species has needs (territorial, swimming such as danios so on). (re ten for goldfish - Any good goldfish forum will inform one to have a least 20 gallons for each smaller gold fish due to water chemistry needs not just size.) Most fish as well, need both planted areas (some sleep amongst plants at night as well as utilize them during the day) and open swimming space. Like us, they like to move about and need stimulation for good health (read Desmond Morris - Zoologists, (or any of his great books) The Naked Ape on older types of zoos and abhorrent animal behavior due to stress of horrific conditions). Cories do love to swim and in the wild are in huge schools in river systems (hundreds even thousands) like above post mentioned they swim all over if given the space. The larger the tank size the better. That said, some I've had that would do ok with smaller size and schooling as well - but due to size 5-7 at most depending on fish (or plant nice and have a great betta set up, java moss on wood, java ferns on rocks - happy betta!). All need plants (Anubias is great as one doesn't need so much sand, a bit for bio culturing) Some can be on rocks, woods and other floating for cover. Most fish (unless specifically high light fish) like shade from plants due to their natural biotype. Remember, hardscape (filters, heater so on and plants rocks wood) take up space and reduce actual water amount. ............................ Doctor Foster and Smith has a pet education site and list minimum tank size for each species. http://www.peteducation.com/category.cfm?c=16+1911 Fish by type at Foster and Smith: (note the minimum of 30 gallon for goldfish and cory) http://www.liveaquaria.com/product/aquarium-fish-supplies.cfm?c=830 ........................................... White cloud mountain minnow. (cooler water fish from Chinese rivers) Very pretty, now (see Dr. Foster and Smith) they have longer flowing fins as well as original. Plants. (this site mentions danios ok for ten - I would not have a school under 20, long at that as they love to zoom full length like speeding bullets) White cloud: New type variation a real beauty: http://www.liveaquaria.com/product/prod_display.cfm?c=830+881+952&pcatid=952 Longer finned variant: http://www.liveaquaria.com/product/prod_display.cfm?c=830+881+950&pcatid=950 http://images.search.yahoo.com/search/images?_adv_prop=image&fr=ytff1-yff3k&va=white+cloud+mountain+minnow&sz=all Priscella tetra... unlike some barbs and tetras, very peaceful... needs a school and plants. Two colors, normal and golden (bred). http://www.liveaquaria.com/product/prod_display.cfm?c=830+890+2747&pcatid=2747 http://www.liveaquaria.com/product/prod_display.cfm?c=830+1535+2748&pcatid=2748 Black Neon Tetra (not a true tetra but beautiful fish) Peaceful, schooling needs plants. http://www.liveaquaria.com/product/prod_display.cfm?c=830+890+1582&pcatid=1582 Other tetras mentioned for ten: http://www.liveaquaria.com/product/aquarium-fish-supplies.cfm?c=830+890 (others on site above as well) Rummynose Glowlight Silver tip Greenfire Diamond Head (pretty) Neons Rasbora (some need more room see link for ten gallon) http://www.liveaquaria.com/product/aquarium-fish-supplies.cfm?c=830+887 Also, how about a moss planted shrimp species tank? ............................................. (suenglee, you need to add to both schools - both of your fish types are schooling fish. Schooling fish evolved to act as one unit and will become stressed and more prone to disease if not kept in schools. (protective/security) So maybe one more cory (I strongly myself over size tanks, under stock and use two filters each tank) so don't add too many for a ten. And at least 3 more tetras. That will be plenty for a ten - again it is water chemistry (bio load) and a ten is not much water all things considered. And all fish need space to swim. Like us in small apartment one goes nuts! I would not add any other species due to tank size and need for schools. (you can mix albinos with normal colors of same fish type though)

While I agree that having a few fish may be more entertaining then just the one and that barbs are cool fish that's where it ends. The barb's Anna described get to be 3" - 4" as adults, they also tend to get a bit more aggressive as they age. They may not be aggressive towards each other but may (or may not) single out the golden barb (if thats what the yellow one is). When setting up a tank for the first time, especially when a child is involved, you want the best chance possible for success. The thing is since barbs are very active indeed, they need alot more side to side space then a smaller Eclipse can give. The smallest tank I have seen suggested for them is a 20L (20 gallon long, about 30" side to side). You have to think of the adult size when you are planning fish for your tank space. Again, I am not saying this can not work at all and it won't work. I am just saying that it is not "ideal" and for a first tank you should stack the chips on your side. The tank will take 3 weeks to 6 weeks + (average 4 weeks)to cycle. The best thing to do is research the nitrogen cycle in aquariums so you know whats in store. Since you have time before Christmas to get the tank and do a fishless cycle I would advise that. The worse thing for a child is to be presented with a tank and have to wait for a month before you can go and get fish. You could do the fishless cycle in the basement or garage hidden from the child, and just wrap the tank box for opening. Then durring Christmas week go to the pet shop and let your child pick out the fish. IME I have found bettas to be very active when people are arround to watch. Cold water will make the fish lathargic and suseptible to disease and parasites, the most common with cold water is ICH. It is true that "if" the room is maintained at a set Temp. you don't need a heater. But all it takes is the door to be left open by mistake and the Temp. will drop. The heater for the betta is a important and wise purchase. For only $20 it will seem worth it if you loose the fish after you have gotten attached to it. Below is a link about the Nitrogen Cycle. It also has links with in the article for fishless cycle directions. This may seem more then you expected just to have a couple of fish, but you will be happier in the end. It also makes the experience more rewarding to know what you are doing. Keeping interest is important because the novelty of a fish tank wears off after a while. The other aspects of the hobby keep the interest up and is a learning experience in itself. It's a hell of allot better then watching crap "reality" TV (exception is The Girls Next Door). Here is a link that might be useful: FAQ

Rolling on down.

Tankless propane vs tank style propane heater. the newer propane and natural gas tank waterheaters are required to be equipped with safety components which has driven the price of gas-fired tank style heaters up in the past couple of years. List prices around $800 for a 40 gallon good for a family of 2-3. Tankless already have the safeties in place and list for $1200 for the unit. If an "average" family of 3 uses 30 gallons of gas a month thru a 70% efficient tank style , the tankless at 84% efficiency would use 24.9 gallon of gas per month. At $2.50 per gallon of LP the savings per month would be $9.75. In 41 months the savings has paid the difference. The warranty for the tank is 6 years, the tankless exchanger is 12 years. The savings over an electric tank is vastly greater. If you burn Natural Gas, the cost to operate is even less. I hope all this helps. I have installed Rinnai, Bosch/Aquastar, Tagaki, Thermar, Saunier-Duval, Paloma tankless and Bradford-White, State, Rheem/Ruud, American, Master Mechanic, Sears tank style waterheaters for over 20 years. Rinnai excels over all the others. The vent is simple and the only caution is against a high mineral/lime content in the water. And the factory support is the best in the industry.