sirdarksol's right, shop around. Last year Walmart ran a special for u to 55 gallon tanks, 1$/gallon. New tanks are cheap up to 55 gallons, the other things add up. I think the figure of $500 is really high though.
I went to
www.drsfostersmith.com to get prices for these, but your local fish store may have some of them and you could save the shipping.....OR they will try to sell you on what they have and it may cost lots more than ordering + shipping........YOU have to shop around.
The list of MUST HAVES, is the same whether you get a 30 or 55. You have to have a filter that will move 10 x the amount of water per hour (unless you get a
canister filter then it is about 5x). So an Aquaclear or other
HOB filter:
30 g = Hagen Aquaclear 70 - $41.29 vs.
55 g = Hagen Aquaclear 110 - $63.99.
Any tank will require a glass cover. approx. $21.99
LIGHTING is the big expense, and can vary greatly in price, but a good quality choice is Corallife the 48" with 2 freshwater bulbs at drsfostersmith is $129.99
the cheap alternative which is what you would probably get at the
LFS is Perfecto Florescent single strip light 48" $52.99, but this is a far second best and only if you Don't want plants.....
These would be the same for any 48" tank. A 30 gallon may take the 36" hoods which would be less, but you can compare if you go to that link.
A Heater is also a must have and 150 -200 watts a visitherm stealth heater is a good choice, on sale now for between $15 &
$18.....
Thermometer $10.00
Air pumps and hosing & air stones can run $20-$30 for everything.
Your gravel and decorations can really add up fast also, but these ARE best bought at your LFS, 2" of gravel is about minimum, and might really run up the cost.....some people go with sand and suggest getting Swimming pool filter sand as a less expensive choice.
As you can see the cost of a tank is just part of the cost, but the accessories will be between $175 & $250 + gravel and decorations for the 30-55 gallon tank.
Getting a tank off craigs list is a good way to go, if you know for a fact that it isn't cracked, that the lighting works, and the filter is good. The tank and light are fairly safe here, the filter ??
As with anything used is buyer-beware.....
As I see it, the difference between a 30 and 55 gallon tank would average $100....but you would have twice the tank, with twice the room.....
