my DIY 500 gallon plywood/fiberglass aquarium
 

They say necessity is the mother of invention. I had a unique situation in which I was given a 12 foot long aquarium. Only problem was inside depth was only 10 1/2". Pretty useless as far as reef goes. So I bit the bullet, researched, and researched some more and began the build.
I could have stayed all glass and just ordered the pieces to widen, but whee is the challenge in that???? Going plywood/fiberglass allowed me to custom build for specific layout based on floorplan. When the smoke finally cleared the tank's final dimensions are 13 feet long, 2 feet wide, and functioning water height is 30". In hind site I should have made the tank 12" deeper, but that meant sacrificing valuable limited floor space in my garage/ soon to be man cave.
There are 2x4 every 6" on back and sides of aquarium exterior on edge to decrease outward force on wood from water. Between the 2x4's I have insulated with 2" ploy insulation on all 3 sides, and the glass is retained by 1 1/2" silicon edge, fron braced with 3/4" plywood sandwiched with pre drilled (prior to fiberglass) carriage bolts to pull glass into silicon seat. Further there is a 3"x3"x3/8" aluminum angle bolted again ith carriage bolts to add additional structural support to glass. Once all that was done each side, the back, an structural support around glass was further wrapped with an other. layer of 1/2" plywood. All work and access is thru the top by way of two 3 foot by 2 foot access panels at each end with one 4 foot by 2 foot access door in the center. I applied 6 layers of fiberglass matt to interior for seal, painted krylon "sea blue" on the 3 visible sides, drilled out and plumbed two 2" overflows.....held my breath and filled it with water.
The aquarium has been holding water now without even the smallest of incidents (or leaks) for over a month and a half now. Im am now in the process of finishing my man cave around this behemoth and plan on moving my livestock currently held in my 120 and 90 gallon aquariums set up behind the big boy. Once operational the 120 and 90 will be my frag/fuge "messy work area" neatly tucked away out of sight. Then the fun task of filling this thing with coral..........WOOPEE!!!!

Please excuse the spelling errors.......man Gary, SPELL CHECK DUDE!!!!!

Wow, that is really going to be something, alright!! Sure hope you don't get a leak...

Great start! Keep us posted.

nice. what did you do with the back glass from original tank??

Cooooool.... !!

I'd love to try building a fibreglass tank someday... one day!!

Damn looking good Gary! Cant wait to see it up and running

Ya, was going to keep back glass, but because the original tank was so narrow it was really scratched all to hell. Too bad too. Cuz I was originally thinking...."hey, if this works I'm building me a shark tank. LMAO

Thanks. Now I have to be a good boy and be patient though. Set it up, cycle it, then take a week off work to do everything I need to do for livestock swap and re-configure "work tanks". Hopefully this spring.

Ya, it was a lot of fun building. A couple things I learned early.....having never ever done fibreglass before resin sets FAST. And fer sher I'm glad I used a respirator cuz the fumes are unbelievable. And you need a very tolerant wife!!!! My wife has been awesome through the process the whole way. She doesn't necessarily embrace my hobby, but she tolerates it which is all I can ask...... Even though I do catch her talking to the fish from time to time. LMAO