Found this today at my local Walmart. Listed MSRP is $19.97, cheapest I saw on amazon was just over $13. I am not sure how well it will work but it was worth a shot for $8.
http://www.walmart.com/ip/Marina-…/126706099
http://brickseek.com/walmart-inve…=1267060
They also have the as seen on tv "My Fun Fish" aquarium for $1.50.
http://www.walmart.com/ip/As-Seen…h/45618883
http://brickseek.com/walmart-inve…u=456188