Large Concrete and Glass Custom Aquarium
I've been keeping fish for about 30 years and reef tanks for about 10 years. I will soon be building a new house which gives me the opportunity to build in a large tank at the center of the house. In addition to being a reef aquarium, the tank will also serve to buffer the temperature of the house - my excuse for such a large tank of water. :) The tank will be on the first floor with no basement under it so it will sit on the concrete slab specially designed to support it which will in turn be anchor to the ledge below.
<Okay>
I am planning to build the tank out of concrete in the shape of an polygon, probably an octagon or dodecagon, with one or more panes looking into each of the main rooms of the house. One of my questions is on sealing the concrete against salt water. I have done considerable work with concrete but nothing exposed to a salt water environment. I have found very little information about the construction of concrete aquarium tanks and what I have found has predominantly been very old  information. 
The technology has changed and I'm hoping to find some recent information. I have found two references to epoxy coated rebar and I am planning to also use PVA fibers in the cement matrix. I have read on WWM that the existence of ferrous metals in the concrete reinforcing can wreck havoc with some marine fishes senses (e.g., sharks). I would also be concerned about oxidization and expansion through rust of ferrous tensile members in the concrete. Have you read or dealt with concrete saltwater tanks and if so do you know what was used for structural reinforcing?
<In small (a few feet in height, length) systems sometimes nothing... other times welded wire, chicken or stucco wire... Larger systems generally reinforced with rebar... tied... and the insides coated with cement mortar...>
I am considering using tempered glass as there are no holes necessary in the glass in this is project. The viewing panes will be on the order of 36" to 48" x 72" to 96" of which there will probably be a 4" lap with the wall on all edges. I am thinking of vertical socketing of the glazing. The panes will be in the upper section of the water column. Should I buffer the glass cement interface with a synthetic or rubber gasket that is siliconed in place on both sides and then seal the edges rather than just using silicon alone?
<I would, yes>
I am leaning towards tempered glass but have a hesitation on it regarding catastrophic failure situations. To date I have only built aquariums with plate glass and acrylic. Have you ever heard of a tempered glass aquarium breaking? Scratching?
<Can break, scratch... generally float glass can be used (more economical) for this size panes...>
I have read about laminated glass (good and bad - e.g., delamination) but almost all of what I've been able to find is on vendor's web sites as well as a few references here on WWM. Have any of you worked with laminated glass in large aquarium projects? Comments? Is there a tempered laminate glass? What special considerations are there with laminated aquarium panes? 
<Laminated glass is of use in moderate height applications... 3-4 feet in height... very clear, strong... not as easily scratched as acrylics>
I have considered acrylic but am inclined against it because of scratchability. I have seen all to many acrylic tanks that ended up looking awful due to the scratching especially along the gravel line. I am still open to it as a possibility as safety is paramount. 
There will be a central shuttered skylight over the tank to provide natural lightning which will be augmented with artificial light during our short days of winter light here in northern Vermont. Due to our climate, overheating is not a concern. I've kept FW and reef tanks in south facing windows for years without problem, taking advantage of the solar gain which in other climates can be problematic. I've found a few references to the use of natural light (e.g., Waikiki Aquarium and some others) but am looking for more discussion of this topic. It seems to me that it would be the ideal lighting, especially for a large tank. 
<These references are obscure, anecdotal largely but can be found through a computer search at a large (college) library>
Given the size of this project I am going to be building several models at 1/1000 scale, 1/100 scale and 1/10 scale before building the final large tank that will be an integral piece of the house and have a capacity of 10,000 to 20,000 gallons plus sumps and refugia. I am looking for articles, books, web sites, discussions, comments, etc about issues related to building a large concrete aquaria. I have found a little information on the web and in the aquarium books I have (such as "Dynamic Aquaria") but nothing that goes into the details about using modern construction and sealing techniques for such a project.
Any pointers or experience with such matters is greatly appreciated.
Lastly, speaking of the book "Dynamic Aquaria", my copy is the original version. I recently heard that there is a new updated version. Do you know what is updated in the new version? Have you read the new version?  Do you recommend getting it if I already have the original earlier version?
<As far as I'm aware, Adey's work is about the same in the new edition.>
Many thanks,
Walter Jeffries
<Much that we might discuss... do write back if/when you come to specific questions, are looking for another opinion/input. Our old companies installed quite a few large aquatic habitats over the years... and the technology has not changed that much as far as I know. Bob Fenner>

Building a Wall Tank Help needed
I am building a basement and would like to add a wall tank unit for my Koi. The viewing wall and tank would be poured concrete in forms maybe 6" thick (thicker if needed) and the glass (Acrylic) section would be recessed for the Acrylic to seal with silicone?
<Possible>
It'll be sealed with either a pool paint or fiberglass. The tank size would be 8 to 10' wide by 5-6' high and 5-6' deep. The viewing glass would be 8-10' wide by 3-4' high.  What I need to know is how thick is good for the concrete walls (I am thinking 6" 
<Fine... with code use of rebar, tied... eight bag mix...>
and 3 sides would be underground) glass mounting area maybe 3-4", How thick should the acrylic should be (I'm thinking 1 1/4" or 1 1/2" thick)
<Two inch would be better... don't know the actual depth of water where the acrylic will be down to... but if this is over four feet, much less deformity with thicker material>
it will be supported on all 4 corners of the concrete and sealed with silicone.  Would all this work?
<Could>
Any suggestions would be greatly appreciated.
<Much to consider in the planning stages re plumbing, filtration, lighting...>
Thank You,
Ron
Also where can I find the answers to this on the forum? If possible can you send me an email?
Thanks again
<Ah, we respond directly to all. Bob Fenner>

Where to buy Aquarium Trim? 7/28/05
Hey,
<Yo!>
I am building an aquarium and have all the specs lined up. However, I do not know where to purchase the plastic/wooden trim that covers the outside edges of an aquarium.  Is there an online site that it can be purchased from?
Thanks for your help,
Raimie Bateman
<Mmm, you can build such, out of wood... from hardware, lumber stores... as trim et al., seal with polyurethane after coloring somehow if desired... or buy plastic and cut, Silicone it on... from aquarium manufacturers... which you can find by searching the Net. Bob Fenner>

Pond-Liner Sump 7/23/05
WWM,
<Eric>
I have been searching the internet for the amount of chemical compounds that could possibly be leached out of a 20 mil or 45 mil pond liner, in a saltwater aquarium.  I noticed another person building a large shark and ray tank with a pond liner, but I was wondering if these pond liners would effect a reef tank.
Thank you for your time
Eric
<Butyl, EPDM, vinyl liners are used in human contact, water ingestion circumstances. They are of use, non-toxic for aquarium uses. Bob Fenner>

New Setup / DIY - 03/25/07
Hello all, and tank you for all of the wonderful information you provide.
I have been researching to build a new 150 Gal reef for about 2 years now, with searching the WWM for about a year.
I currently have a 55 gal fish only with some LR, current equipment is two power filters, a Berlin skimmer w/ a Rio 2100 pump, and a few power heads for flow. Current stock is a maroon clown and a yellow tang.
My plans are to build a new tank (60 x 24 x 24). I started with 4x4's as the frame using galvanized corner braces.
<Do paint over these... rust-proofing...>
I added several 2x4's in the center, splitting the center into 3 parts. The top is 2 layers of 3/4" CDX plywood with 1 layer of 1/2" cement board, as I plan on finishing the counter in tile to match the rest of my kitchen.
<Neat>
My neighbor who is a general construction worker helped me design my stand. We estimated the weight of everything to be somewhere in the 2250 - 2500 Lbs range. I also added several 4x4's under my floor for weight support.
<Good>
The finished size of the stand is 60 x 48 with 4x4 legs about 38" tall. This was placed as a dividing wall for my kitchen and dining room, with a breakfast bar on the one side. I work at a printing shop so I was able to acquire some printing blankets for placing my tank on they are about 1/8" thick made out of a rubber/canvas layers. I thought this would be a good replacement for the thin layer of foam.
I started with the plans at GARF.org but found a few conflicting suggestions from here, one is not to float the bottom glass (raised a 1/4" from the very bottom).
<... nice, enthusiastic folks... but not entirely well-informed>
My current tank is an All Glass,
<The manufacturer I take it>
it has a floated bottom on it with a center support in the middle of it. I have read about why to float it, but have not found anything on why not.
<Mmmm, not much to state... well-made tanks... can support most all with such floating bottoms...>
I went with 1/2" plate (float, etc...) glass for all of it. I also did some reading on bracing it, but could not find much on what I plan on doing.
<? Should have come braced... as in the top... by All Glass...>
My plans was to use oak? 2x2 and cutting them into a L shape to fit over all edges of the tank. Do you think this would be enough bracing?
<Did you make this tank... as in all glass with no capitals?>
also does anyone know of what would be a better hard wood to use too?
<Whatever is used the top needs to be braced somehow to prevent bowing... cross-braced, Euro-...>
I had the bottom pane drilled with two 2 1/4" holes for 1.5" bulk heads on one side (reason was the tank will be visible from 3 sides and I really didn't want to see an overflow in the one corner :)
I also have planed to get a flow rate of around 2500 - 3000 GPH,
<Not through these two fitting sizes you won't...>
what is your opinion of the Sequence Dart pumps?
<Good products. Quiet, dependable, have good service factors...>
The canopy is going to be a custom built full height cabinet, with doors on both sides for easy access.
It will start from the top of the tank with the first shelf around 18" for my lights to mount to. I was thinking of MH because of the depth. If so 250 or 400?
<Either... I like the smaller wattage... unless you really have need/use for the larger... AND matching all else to accommodate the boosted metabolism... waste heat...>
I like the looks of the 20k ones better (I am a blue fan :) but selecting brand, type, single or dbl ended bulbs is making my head spin.
<Keep studying>
The cabinet is going to have an empty channel on the side next to the wall to allow air to flow through my lights, up and out of the house.
<Will need more than "flow"... you'll want to plan, provide to blow air in and out...>
The climate of were I am is more cool than warm so I dint think over heating will be much of an issue, but keeping it up probably will be.
<The fans can, should be linked with thermal switches...>
Under my stand I built a floor drain out of concrete, It also has both hot and cold water for maintenance.
<...? You'll need/want to treat, store new water elsewhere for use. Not tap...>
I was going to put my old 55G under there for a sump setup. Can Plexi be siliconed to glass for sectioning my sump?
<No, not well. See WWM for other ideas... or plan on Siliconing in glass partitions permanently>
I am planning on using around a 6" deep sand bed with about 130-160 LR. My only supplier around here is about a 80 mile drive and all they have is Fiji LR, I did get some there for my 55 and it is descent stuff but they are selling it for $8.50 a pound.
<Look to the mail-order houses... chat with folks on BB's re who they found/find to be fair dealers/deals currently. Buy box quantities... cure in-place>
(consequences for living out in BFE)
Has anyone used a black sand with good results?
<Mmm... much to state... but most all such material is inappropriate... won't buffer, provide much biological surface area... often needed...>
I haven't found very many people that use it.
Does anyone recommend a good on-line place for anything I can't get at my LFS.
<Again... best by far to query others on the specialty BBs here>
Will send pics when I can finally start on this.
Thanks
Chris
<Do please read my comments closely... and read here: http://www.wetwebmedia.com/marsetupindex2.htm
re Plumbing/the size, number of your through-puts... Lighting at the bottom... and here: http://www.wetwebmedia.com/marine/setup/index.htm
The second tray down... re tanks... bracing... Do NOT fill this tank w/o internal bracing. Bob Fenner>

Molded (aquarium) Frames
Can you tell me where I can buy a molded top and bottom frame to construct an aquarium?  I have all the glass - just need the frames. Thanks
<You can try contacting a manufacturer, like Perfecto, Oceanic... and see if they will sell these to you. Bob Fenner>

Sealant for very large glass and stainless steel tank
I have a project in progress of built an aquarium of  6,000 gallons of fresh water fish, will be with glass walls, I have everything figure out, the only thing that I would like to be help is to find a caulk sealer to help bonding or sealing concrete to glass , and glass to stainless steal. Or if you know a contractor will help a lot.
I appreciated your help.
<If this system is not too tall (up to six feet, 2 meters or so) and the frame itself is structural (that is, intended to bear all the force of the water, 100% silicone will do as a nesting, sealing material. Bob Fenner>
Sergio Gonzalez

Pond Liner for Salt tank set up?
Bob,
First off, LOVE THE site!!
Just found it and it's a wealth of info. I have a quick question for you.
I'm considering making a large salt tank and was wondering if the normal pond liners would be ok for constructing a salt tank used for sharks and rays etc..... If pond liner won't work is there any other material other than the Rubbermaid tanks etc...... I want an indoor pond but with sharks I figured the cheapest way to get a 6x12 tank would be to go pond liner..
Thanks and keep up the good work. and thanks in advance.
<You are welcome. I have built such "shark tanks" (and more) out of pond liners (nominal 20 mil. polyethylene ("water bed") types to 32 mil re-inforced, EPDM, Butyl Rubber... with good utility. The large Rubbermaid tm oval "troughs" are also very useful. A note of caution: Do make a complete, secure cover over either, as even apparently sedentary sharks can/will launch themselves out... Bob Fenner>
Regards, Robert C. Taggett

Building Tanks
Hi everyone,
<everyone in my head? or are you just referring to the WWM crew at large?>
First off I 'd like to say thanks to Anthony for previous advice about my flower pot (Goniopora). I have a new refugium and the coral is doing really well. No more dark spots and even some polyp extension.
<ahh... great to hear success/progress>
I read the FAQ's daily and absolutely love you sense of humor .. you were in rare form today/yesterday.
<HA! Thank you... that makes two people now that understand and appreciate it>
We have a 125 gal. tank which we have maxed out, so the natural answer is of course to get a bigger one. Would like to build one "in the wall" when we finish our cellar. I have looked around and can't seem to find any really good info on building the big (500-600 gal.) tanks. (Of course I found the 4,000 gallon tank with the scuba diver ... not quite what I had in mind!!) Curious about building the tank with cinder blocks with just the glass/acrylic for the display window. Any info you could point me to would be great.
<yes... I have a great friend who manufactures custom aquaria who has shared/taught much on this matter. Truthfully... what you would like to attempt is actually a difficult task for even experienced folk. I would strongly advise you against it (for perspective... I have personally built more than 100 aquaria 200+ gallons and I wouldn't try a concrete and glass structure). Such aquaria are dependant on a very thick flow that is EXTREMELY solid... no chance of even the slightest settlement (engineered/reinforced concrete, etc). Then we are talking about some skillful maneuvering of a viewing pane that is to be suspended/mounted as "floating" (not resting on the floor and rocked into place but literally swung, siliconed and clamped). Many public aquaria with older displays employ this type of vessel... in some cases the tank was filled just after the silicone and glass were set to use the mass of the water to support/hold the clamped pane in place! In many cases they leak and have to be resealed several times (although once a good seal is made they will go for many years assuming the blocks don't shift/crack). Even if this tank is in a basement where you can afford the leaks... it is a pain and an ancient technology. I would sooner see you make a wild saltwater pond with an island in the center (one tree island with a mangrove tree under a spotlight... and a miniature shipwreck of the USS Minnow beached... Hmm... perhaps we'll have to rename the island then?!). Anyway... all glass 500 gallon aquariums can be made easily or even fiberglass units with a viewing pane (although also a little tricky). See if you can scavenge any good deals on 5/8" or laminate glass, or barrels of fiberglass resin <VBG>. I just saw a cool thread on Reef Central about a 1300 gallon glass aquarium...yeeha!>
Once again, can't say enough about your site! Thanks, Beckie
<best regards, Anthony>