1500+ gallon saltwater build....maybe. Need some opinions.

[SeanCJ]

Hello all.
I am contemplating building an 8' long by 6' wide by 6' tall plywood saltwater reef tank.
It will be wall recessed in my finished basement. There is a 15'x10' room in which the tank will sit recessed and will house filtration. It will sit on a concrete slab floor with footings directly underneath.
I'm planning on 2x4 frame construction, 12" on center, with a double layer of 3/4" plywood interior.
Viewing panel will be roughly 84" x 60", most likely glass.
The goal is to make it look more like a museum/public aquarium display. I envision two or three well spaced tall rock pillars with corals growing out and up, but with the majority of the tank being open water for large fish to swim about.
I would love to use the Blue Max liquid rubber, but I just can't seem to find any links, either here or on Reefcentral, to previous builds using this material. Everything I read seems to implicate that this product will work, but I'd still like to obtain any previous experiences with it and get advice.
Question: With my 2x4 frame construction, plus the double layer of 3/4" plywood interior handling the rigidity of the structure, will the Blue Max provide the necessary water protection?
I really want to use this product for its ease of application and clean up, no fumes spreading throughout the house, and its color. I have a professional grade paint sprayer so applying this material would be quite easy.
Any advice, tips, suggestions, and/or links to previous Blue Max builds would be greatly appreciated.
Thank you.
Sean

 

[SeanCJ]

Beuller....Beuller....?

 

[spiff]

I can't vouch for the BlueMax. I think you'll be pushing boundaries big time trying to go 6 feet deep and using plywood. I had difficulty doing it while using cedar 6x6's. I'm sure its possible though. There will just be a whole lot less room for error. And considering that, I'm not sure going with a sealant that hasn't been tried and true is a good idea.. too much of a gamble.

I would recommend Sanitred.

But good luck. Sounds like a wicked project.

 

[SeanCJ]

Thanks for the reply spiff. I think I'll bump up the side wall construction to 2x6s or even 2x8s should I decide to go through with this. I've also considered concrete, but the idea of breaking a concrete tank down should we ever decide to move does not sound fun.
I'll research the Sanitred too. Thanks for that suggestion.

 

[yogurt_21]

There is a 15'x10' room

and we're not seeing a 15'x10' build because?

lol

6' should be fine for plywood, it's the window thickness that's the issue as it's expensive.

take a look at the larger builds in the sticky thread, frame it well and you're fine for that depth.

 

[spiff]

LOL.. I love how folks with no experience so easily dismiss certain issues. I have been flamed into the ground on other threads regarding inferior builds when I have suggested concern about it. People will start talking out their azz about how its such a bullet proof build, ect and then it ends up falling apart and suddenly every one shuts up. I hate to say I have always wound up being right though. I have seen more 5ft deep plus builds fail than succeed.

As I said, it is possible, but will be pushing limits on all fronts. To just say, "oh yeah, you'll be fine" is down right idiotic to the extreme. Especially for someone who has never done it.

 

[yogurt_21]

now that I'm in a better mood,

first, I probally have more structural engineering experience than you and all of your friends combined. So please refrain from trying to determine people's experience level based on what you've seen in an online forum.

second, yes you're 100% right I shouldn't have implied it was "simple" to someone who's never built anything in this weight class.

third, this should be helpful

http://www.aquariacentral.com/forums/showthread.php?t=89278

on the issue of pressure (we'll leave out forces for now) by that calculation you're looking at ½ xdxWxh^2 *where d is density not depth

it comes to .5x.036x96"x72"^2 = 8957.95lbs of pressure on the sidewalls.

for that, you need to build the bracking of the walls of the tank to be able to withstand that pressure.

If you're going 2x4's you'll need to do actual framing on it rather than 12" on center.
I'd suggest going with a floor truss style like this http://www.google.com/imgres?imgurl...a=X&ei=GzOSTJ2lLIyisQPFl_DACg&ved=0CC8Q9QEwAw

and then spacing them 12 -15" apart.

you could try to go for 2x6s or 2x 8's and go with this design
http://www.monsterfishkeepers.com/forums/showthread.php?t=181445

but I personally like the peace of mind that goes into a truss style bracing system.

I'd also use metal angle brackets along the bottom instead of the traditional diy method of screwing the bottom plywood into the side plywood.
http://www.shortrunpro.com/reinforcing_metal_angle_brackets_s_vhv39ytw_vhv1ytw_vhv1ytw.aspx
that would give more resistence to the pressure on the bottom of the tank.



@ op now if any of the above seems out of scope for what you can do, go shallower. Anyes the 9000lbs of pressure may seem like alot but realize that's spread over the entire side of the tank and if you take 9000lbs over 48 square feet you get 187.5lbs ie you need something that can consitently support the weight of a man per square foot, floor systems typically can handle more than that.

edit: http://www.monsterfishkeepers.com/forums/showpost.php?p=883263&postcount=87
probabally the most relevant to what you're trying to do.

 

[spiff]

Sorry man, didn't mean to throw some name-calling in there. Uncalled for for sure. I must have had a bad day myself.

 

[BadOleRoss]

Guess now is a good time to throw my .02 in. The first thing I would consider is decreasing the depth to 4'. Standard plywood is 4' wide so you could run it lenghwise and have less seams to deal with. A reef tank 6' is going to require some serious lighting, 4' would help with the lighting needs. As far as the wall, I think a 2x6 or 2x8 is the way to go. I cant throw all those fancy formulas at you that Yogurt did but as a fat guy I can tell you that 2x4s wont hold back the water.

 

[VLDesign]

"Viewing panel will be roughly 84" x 60", most likely glass. "

Until you get a quote for some glass that will handle that pressure. On my 30" tall 1500 gallon tank, 3/4" glass was used and it cost 1/3 the total cost to build the tank and sump.

I would seriously consider going acrylic with that depth.