I have a Jelly Cylinder 5 at my office and absolutely love it! I tried one for home and decided to order a Kreisel 15 Jellyfish Aquarium . I am not happy with it and its flow. I reached out to customer service to ask if it can be replaced with their Jelly Cylinder and I would pay the upgraded price. The person responded how she had one on her desk and was having some of the same issues with it. No offer to replace it. I have found some other places that sell tanks and larger cylinders, I may try another place and just through this one in the trash if they wont help out in replacing the tank. Need to figure out something since I want to order one for my daughter!