Please help! I have searched the threads and couldn't find the answer. I need to make a 3 tier cake but the middle is a fish bowl. I will either use a glass or plastic fish bowl and it will be a fondant fish inside so he won't need air lol. I'm so nervous about this cake and regretting agreeing to attempt it. I appreciate any advice, TIA!!! 

Here's one I did some 8-10 years ago.  Sounds like your's will be very similar.   I don't remember much detail about it but if you have any specific ?s shoot me a PM.

I do remember using double cake circles under each cake and I did talk the bride out of using real, live fish because the reception was on a boat that would be taking a cruise around the lake and I was concerned 1) about the fish getting air and 2) water sloshing onto the cake.  I never had any feedback from the bride so I guess there were no problems. http://cakecentral.com/g/i/59369/a/60369/

AI would use sps support under the fishbowl and cover the plate with Fondant under the bowl. I would put top cake on foam core line the top Of bowl with fondant or double sided foam tape and put top tier On. Stack on site. I think it won't be too hard ! Good luck !

Thanks ladies, gorgeous cake! I will post pics and let you know how it turns out!

OMG this sounds so brilliant and different, when you have completed it please share the pic ;-)

yes beautiful cake, kakeladi!

i think i would color the bottom of the board that sits on top of the fish bowl--color it a light blue watery design for continuity--for the short peeps ;) 

probably not necessary but an idea--

also mirrors would be fun on this if the weight of the cakes is not too much--

AMaybe if you use a fishbowl with a perforation in the base you put a long rod through the middle that held the bottom and top tiers, and cover the fishbowl segment with some fondant seaweed/seashells. That would work if you don't need to put water inside. If you do, I'm thinking you could use that kind of gel used for "sea themed" candles, it doesn't dissolve unless you apply heat; that or Jello, but the fishbowl-rod would need to be sealed where the little base hole is, so the gelatin doesn't have any place to go. I hope it turns out fantastic!