Yet another question, Tank 05/29/2008
Now a day one can find aquariums in all shapes and sizes. The more advanced people can even build their own, though I would live in fear of discovering a water world upon what had been my floor. Though having people who built aquariums for a living build me one sounds nice, if only I was rich.
<<Its actually not that hard to build an aquarium, my previous reef, 110 UK Gallon, was hand built by me, and I had never built a tank before>>
This range of tank sizes for the same amount of water how ever makes a problem. Fish "A" need "X" amount of water. Just about every body has a idea on how much "X" is, though often the numbers are not the same. Maybe having the same measuring system worldwide would help every one with their numbers, but still it give a good idea that fish "A" want fit into tank "B" because "B" can't hold "X"
This bring me at last to my question though I had to ramble on to get to it. Is there some kind of secret magical system out there to determine size of the tank for the size of the fish be on "X" amount of water? I was thinking maybe it might be the fish length times some unknown number, but that would not work unless your tank was a square. Though if you had one system to determine length and another width it might work.
A person could get a tank made were the fish could swim the length of their living room, but would have to fold it's self in half to turn around. A lot of tanks are 18" wide but would a 12" fish in a school really like only 18" to turn around in?
Just how do you tell when a tank is now to small for the fish that was raise in it? "X" amount of water can only get a person so far and "X" tend to be when the fish is fully grown which can lead to really big tank, very little fish, that might live long enough to be big fish, so long as the filter don't eat them first.
<<It does pose an interesting conversation point. in theory. However, as there are that many fish available for consumers / hobbyists to purchase, to me, it does not make a mathematical equation plausible. The tanks we buy, should, if starting from scratch, be purchased based on the stock we want. An example, I want to keep an Paracanthurus hepatus, so, I would go out and buy (or make) a tank suitable. Which, in this case, would be 120 gallons plus (5 or 6 foot preferably). The point is, tank size is all based on the stock, no real need for math to be involved. Just an opinion on the subject of course.>>
Oh before I forget thanks for answering my question, it nice to find people out there that don't start heading for the door when I start talking about fish again.... family's can be rather odd at times. One would think verbal information about fish was some kind of new form of torture by the way they act.
<<I hope the above helps, regards, A Nixon>>

DIY/Acrylic Thickness For Large Tank 5/14/08
Dear WWM Crew,
<Hi Rob>
I'm building a large tank and I'd like some advice on the thickness of the acrylic I should use. The tank will have acrylic panels on the front and both sides. The back and bottom will be concrete. I've attached some images for clarity.
The dimensions of the sheets are as follows:
Front pane:
3000mm x 1500mm or 118" x 59"
Side panes:
2000mm x 1500mm or 79" x 59"
The water height will be 100mm above the top of the pane, so the water height from the bottom of the pane will be 1600mm or 63". I also plan to use piston type wavemakers so I presume the variable water depth under the peak and trough of the waves will add to the pressure on the panes. I was hoping to be able to use 50mm since this is the largest easily available sheet size. Unfortunately after using Cyro's calculator this seems a little optimistic. The calculator I used is available here:
http://www.regalplastics.net/aquarium.htm. The calculator showed that 60mm
for the side sheets and 70mm for the front sheet is more appropriate. I'm hoping that their calculator is overly conservative and 50mm will be fine. Based on your experience do you think I'd be able to use 50mm thick acrylic for the front and side panels? I can handle a very small amount of bowing on the viewing panes but I'm not prepared to take the risk of catastrophic failure.
<Rob, you should be fine here with a near 2" thickness. I can say that Tenecor manufactures a similar size tank and they use 1 1/4" thick acrylic.>
Thanks in advance,
<You're welcome. James (Salty Dog)>
Rob

Re: DIY/Acrylic Thickness For Large Tank 5/16/08
Thanks for your reply, James.
<You're welcome.>
Do you think I could get away with 40mm? This would be a little over 1 1/2 inches for a 63 inch water height?
<I really do not want to tell you it is OK, I'm no acrylic expert. I was basing my response purely on what size acrylic Tenecor uses for a similar tank. So, if it is OK with them, I'm sure it would be fine with you.>
I presume the Tenecor tank you're talking about is the "Ultra Rectangle U1320, 120 x 48 x 60", yes?
<Believe so, quite pricey also if I recall it was over $15,000.>
My source is http://www.tenecor.com/acrylicaquariumchoices.php. I presume the water height must be around 57" or so with this tank so it seems possible I could use 40mm.  Apart from the price difference in the sheet size, some suppliers only stock up to 40mm here, so hopefully I'll be able to get a more competitive quote.
Thanks again in advance,
<You're welcome. James (Salty Dog)>
Rob

Re: Yellow Tail Fangblenny, Meiacanthus atrodorsalis  4/13/08
Thanks Scott,
<Welcome Lawrence.>
All good advice as per usual. The boxfish is really happy at the moment, very friendly and watches us as much as we watch him, but I know he'll need larger accommodation in the future.
<Yes he will, but these sure are fun fish to watch, some of the goofiest fish I have ever seen!>
The plan is to move him in to the Ubertank we have planned, a truly mammoth system hopefully.
<Sounds good.>
Do you know of a good link or book regarding the construction of large tanks, possibly with block work and fibreglass sides and a single glass/Perspex front?
<I know of no such book and have actually started on one (yes Bob, finally!).<<Yay! RMF>> As far as websites, there are a few that can guide you through such a project. Of course WetWebMedia.com has much useful information in this regard throughout the tank building FAQ’s. Another site worth checking out is the Garf.org DIY pages. This will give you the basics of how to, but the automated calculator calls for too thin of materials for my taste for the larger tanks.>
Laurence
<Have a good day, Scott V.>

Acrylic aquarium... fabrication. Looking to learn in/from Malaysia, Thailand   5/3/07
Hi Bob, 1. I would like to learn to bond and bend 1 in to 2 in thick 8 ft length acrylic sheet. 2. Is there any colleges in USA or elsewhere I can learn?
<Mmm, none that I'm aware... but no doubt there are such...>
3. Is there any books or website I can refer to ?
<Ditto>
4. Is there any companies out there who is willing to teach ?
<Contact them... likely the closest such "acrylic/Perspex..." Plastic fabricator/dealer in your area is worth calling, contacting re whether they'd take you on...>
I am willing to pay for it. Thank you.
<What area do you live in? Do use the Net (search tools) and Yellow Page/Phone directories under the word "Plastic" to find companies in your area... There are several places in the U.S. that you might visit re.>
Subject : email from Mr. Thanaphon Manavatioeth of Thailand 1. I recently read your email regarding coral reef aquarium. 2. Salt water fish is extremely difficult to maintain, costly too. 2a. Many people failed because of cost and difficulty to maintain. 3. For a start, I would suggest to start with fresh water fish, which is much easier to maintain and low cost.
<Good advice!>
after you have gain the necessary know-how, than do the salt water fish.4. You mentioned that you have worked with acrylic aquarium before, if you have any experience in bonding and bending 1 in and 2 in thick 8 ft length size ? I would like to learn from you. 5. I am from Malaysia, if necessary we can meet up in Thailand.6. My email address is kimchoo_59@hotmail.com .  Thank you.
<Mmm, I will take the risk and post your email addr. here... Am hopeful that someone/s will come forward to assist you. Bob Fenner>

Black Aquarium Frames  2/16/07
Hello Crew,
I would like to build my own aquarium but I can't seem to find the black framing material. I am constructing an odd size and All-Glass or Glass Cages  does not have what I need.
Any suggestions?
-Deb
<Yes... do contact Oceanic and Perfecto re whether they will supply you (have in years past... though the trade has undergone... what's that polite euphemism? Consolidation... If not available from the aquarium manufacturers, consider fashioning your own... do know that these "frames" are not structural... so yours need not be either... Bob Fenner>

Aquarium rims   1/27/07
I looked through your search engine but couldn't find an answer.  
  Do you know some place that sells plastic aquarium rims to the public?
<A few of the manufacturers will sell this to the general public... I'd check with Oceanic, Perfecto...>
I am re-building an old 70 gallon aq and would like that support on the top and bottom.  
<Mmm... more for the assembly process and looks than physical strength...>
  If not do you have any other suggestions on how to make one out of something besides wood?
  Thanks.
  -Steve Balogh
<Please see WWM re DIY Glass aquariums, Repair... Bob Fenner>

Skating on Thin Glass  1/23/07
Hi Crew,
<Hi Dan, Pufferpunk here>
Just a very quick question for you today. I recently purchased a second-hand 72x18x19 aquarium with stand and hood as it was absolutely dirt cheap and is in excellent condition. It's 2 yrs old but has never been used. It is made of 1/4" glass with a 1/2" base. It also has two 9" wide braces. I have done a lot of research on your site and others and seem to be getting mixed opinions whether this glass thickness is going to be too thin. I figure it's best to ask you and be sure rather than fill it up and potentially find out the hard way!
<Sounds like you've bought yourself a nice, big reptile tank.  It will not safely hold water, IMO.  ~PP> <<Is on the borderline... but this is likely intended to be a fish tank. RMF>>
Thanks!  Dan

Re: Fish Tank Glass Thickness  1/23/07
Thanks for the quick reply. The tank is definitely meant for fish as it already has an in-tank overflow built into it ready to be connected to a sump. I guess all I really need to know is if you think it will break or not when water is added.
<I suggest going to fish tank manufacturer's websites, like AllGlass &  Perfecto & finding out the thinnest glass those size tanks are sold in.  You might even want to contact those companies & ask them if your tank is OK as is.
~PP>
Dan

DIY refugium question  - 1/18/07
Hey guys,
I'm helping a friend built a refugium for his 60 gallon. How long  do we have to wait before we can add water and live rock and connect it to the main tank?
Thanks again for helping us.
<...? What Material are you using here? Glass or acrylic? What kind of sealant was used? Assuming glass and silicon -- I would wait 24 to 48 hours, as long as 72 hours for Acrylic. Hope this helps! -JustinN>

DIY Refugium setup Q -- A follow-up - 1/19/07
Hey Justin,
Thanks for the reply, I am using glass and silicone. I have one more quick question. Do I have to use a special solution to clean the refugium after the silicone has cured. Doesn't silicone have a chemical that will leak into the water if not well cured/cleaned before adding water?
<No, the only concern here is that you got a silicone without an anti-mildew additive in it. This additive is what is toxic, and if your silicon does not contain it (it is usually packaged as "Kitchen and Bath") then the cure time is all that is necessary. Cheers! -JustinN>

Aquarium building qualifications?  9/9/06
G'day from Down Under, Crew!
   <Howdy from Jamaica!>
  Greatly admire your work and dedication on making WWM such a fantastic read!
   <Thank you>
  I've been reading through your many pages and FAQs on tank setup and business issues. There is however one facet that I'm still puzzled about, and that's with regards to qualifications on aquarium construction.
   <Mmm... here in the States... pretty much anyone willing to try, and risk being sued (!) for troubles...>
  I'm thinking about purchasing a custom made tank from one of the larger pet shops here in Melbourne but am worried about their qualifications on tank building. I'm not really referring to the generic Marine Biology degree but am more curious about how they can come up with the calculated thickness of a 12mm glass pane for a glass/ply tank or the loss in head height for a pump with an additional UV  sterilizer on a by-pass.
     It struck me that almost anybody off the street may be involved in tank building, as long as they have 'many years of experience' in this industry or if they can provide a portfolio of previous work. Can any Tom, Dick and Harry accomplish the task as long as they have access to WWM and rip off data from your tables and charts?
   <I believe so, yes>
  Hence, my simple question after my long-winded intro is; Do you know of a specific course or education program that I could ask of from the builder of my future aquarium as to ensure that he/she is properly qualified?
   <Actually... no... am thinking anyone who might try the business would be careful (enough) to not offer shoddy, unsafe merchandise... But have known small-time (local) operators over the years that came in/went out of biz due to tanks coming apart>
  Thank you for your kind assistance and apologies if I've gone off-track.
  Cheers
  Colin
<Not at all... good question... Just don't know/have much of a good response. Cheers! Bob Fenner>

Silicone Toxicity/Refugium Lighting - 09/02/06
Hello crew...
<<Howdy Mike>>
Ok I built a refugium using a used 20 gallon tank.
<<Cool!>>
I welded acrylic to create: an intake compartment where the skimmer will sit, under-flow to the refugium compartment, over-flow to an activated carbon compartment, overflow to an empty compartment, overflow to last compartment with lower water level (waterfall for gas exchange) where water is heated and returned to main tank.  The tank is divided lengthwise so that the intake/skimming, carbon, empty, and heating compartments sit in the back and the entire front of the tank is the refugium, which once established will conceal the other compartments from view and hopefully make the tank pleasing to the eyes.  The acrylic dividers were welded together with solvent and then siliconed to the glass tank.
<<Ok>>
Is there a problem with using silicone to join acrylic to glass?
<<It's not recommended for structural applications, but in this instance/for this application it's no problem at all>>
The tank is working perfectly in my fresh water test runs, but I had heard that this may be a future problem.
<<...?>>
Also, I ordered live rock and it should get in tomorrow (9/1).  The silicone has been cured for about 48 hours.  Can I use the refugium to cure my rock or will the silicone damage the organisms on the rock?
<<It will be fine to use the refugium>>
Someone told me I had to wait several days.
<<Nope...give the silicone 24-hours and you're good to go>>
Do I need to provide light for the rock while curing?
<<Is not a necessity...please see here:  http://www.wetwebmedia.com/lrcurefaqs.htm >>
My main tank has excellent lighting, but I just have a 38 watt full spectrum florescent for the fuge.
<<Depending on what you plan, this will likely be fine...see here: http://www.wetwebmedia.com/refugltgfaqs.htm >>>>
Thanks,
Mike
<<Welcome.  EricR>>

Refugium... glass cut too short   9/2/06
trying to make a 20 gallon long refugium for a oceanic 58 gallon tank. I had some glass cut at a local store and i measured the tank 11.5 inches , I'm short a quarter inch on both sides anything i could use to make up the difference so i can silicone them.
<Mmm, no... but if you'd like to salvage this project, you might get by via siliconing strips (two inch or so wide) of quarter inch plate on the short sides. Allowing this to cure (a day) and siliconing to these in turn. Bob Fenner>

Glass enclosure question for non-fish person   6/10/06
I should start by saying this is for a small animal (chinchilla) enclosure but nobody making cages seems to have a clue about glass enclosures that I've found, or if they do they're certainly not interested in sharing information with some crazed nut who wants to do it himself! (Egads, man! Have you taken leave of your faculties!?!?!)
So, here I am, up the proverbial (fecal) estuary with no visible means of propulsion as it were, and I wondered if you chaps might be so kind as to help me.
<Will try... after all, "a glass box is a glass box">
I have a question about corners and joinery, if that is the correct term.  I am trying to make an octagon shaped enclosure with the following dimensions:
Height: 48 inches
Width: 43 inches
Essentially, each of the 8 sides will measure 18 inches across by 48 inches high.
I know the angles at the joints are 22.5 degrees each but my question is about the strength of the joint itself as opposed to a standard 90 degree joint.  Would you recommend a metal joint brace of some sort for each corner or would you use some other method of adhesion?  
<Mmm, nope. The Silastic/Silicone itself, with or even w/o the cutting/joining of glass joints is very strong indeed>
Bearing in mind that a chinchilla is basically just a cute rat with a nice fur coat on him who chews like the bloody dickens, I'm tending to shy away from a sealer for fear he'll wind up ingesting it.  Any clues on what to do or who (if not you) I might chat up for answers?
<There will be a minimum of material available to this animal on the inside if you run your beads properly. The material is chemically inert once cured...>
I've talked to window and glass people but they've all got their own ideas about what to sell me whether it works or not, and I'm running out of time and patience for that lot.  If there is a metal brace that can be used to line the edge of the glass and hold it whilst being fashioned to another piece at a constant angle,
<Not necessary... you can build a jig for such, but have build hundreds of such enclosures with just sturdy (strapping type) tape, built in sections/pieces, on-top of the intended bottom... on a level, planar surface. The 100% Silastic/Silicone is "sticky enough" to hold the two piece sections, later joined as four, eight... by itself>
could you please enlighten me as to what exactly it might be called so I can re-commence my search for either 32 or 64 feet of it?
<No bracing necessary, or desired, other than the tape if you'd like>
I apologize for not having a more subject appropriate but after perusing you FAQ section for a bit I figured you chaps might just be of some assistance.  Thank you for taking the time to bother with the likes of one such as I but I didn't know who else to try at this point, so thanks again. Truly.
Sincerely,
Thomas Mc Leod
<Give us a write back if you have further questions Tom. Bob Fenner>

Large Tank Questions and Outcome of Silicone II  5/29/06
Hey guys, wanted to bounce a few plywood tank questions off of ya and provide experience input concerning Silicone II. First things first, I have two large tanks which I recently set back up (long story), I used swimming pool paint which worked VERY well and had no adverse effects on sps or other livestock. Long story short, when I set them back up, I used Silicone II to reseal the corners of the tanks. It has now been 2 months, I am getting consistent trite readings of .025 (Salifert), not high but it should be 0. I am now faced with daunting task of replacing the silicone with Silicone I. (I tried everything including adding live bacteria, carbon, Purigen, all types of stuff, bottom line, at least in my experience is that Silicone II isn't reef safe, live rock is 8 years old)
<Yikes...>
Now on to the large tank questions. I searched all over, including GARF for info on epoxies. Swimming pool paint with plywood tanks works for several years but ultimately you end up with micro cracks in the paint that need to be patched with silicone or repainted. I am building a tank that would be approximately 1500 gallons, I want to use a reef safe epoxy but I cant locate where to buy Rustoleum or DuPont potable water epoxies, do you guys know of anywhere, or know of any alternative epoxies that might work?
<Mmm, I'd look into your local swimming pool supply places here. I have used Nelson/Nelsonite with good results as well as (more pricey) Spar products (intended for the boating industry)>
I have also come to the conclusion that since this will be a reef, I am best using glass versus acrylic since acrylic will ultimately get pitted by coralline (I even looked into Polycarbonate but from  what I understand it bows too easily). The glass dimensions would be front panel 96"x30", would 3/4" Starbrite or Starfire glass be thick enough in your experience?
<Yes>
From what I have read it is reinforced glass, and while pricey, is much stronger
As always thanks,
Tom
<Thank you for sharing Tom. Bob Fenner>

DIY/Aquarium    3/17/06
Hello,  <Hello James, nice name.>
I am building a new tank for my marine fish.  It is going to be 3.2  metres (126 inches) long and 1,3 metres wide (51 inches) and in 19mm  
glass (0.75 inches).  How high should I go with this pressure of water?  They are saying <Who is they?> I can go 1 metre (39 inches) but I think that could be too high?  What is the ideal height in your opinion?  <If it were me, I'd just follow dimensions of commercially built tanks somewhat close to your size. Then you know you should be safe.  Do keep in mind bracing and glass/acrylic thickness.>
Thanks in advance,  <You're welcome.  James (Salty Dog)>
James.

Fiberglass Use   3/14/06
Hello wet web,  <Hello Mike>
   Thank you for your response on my skimmer question. Here is another for you. Would it be a problem if I used fiberglass as sealant instead of cylicone <silicone> or would it be toxic to fish? Is there a certain brand that I have to use or will anything from Lowes or Home Depot work? <What is the sealant going to be used for?>Thanks for the help.  <You're welcome.  James (Salty Dog)   
Mike

Re: Fiberglass for sealant... pb?  3/15/06
The fiberglass will be used to seal some plumbing, so water will come in contact with  it. <Either I'm missing something here or I don't see the point in using this stuff.  If this is to be used for sealing threads it will be next to impossible to remove the fittings after it sets up.  Much better to use Teflon plumbing tape.  <James (Salty Dog)>   
  Mike

Some questions about a plywood tank   3/10/06
Hey crew, excellent job on the site.  I've been reading for 4 nights now and am still forging ahead to learn more.  I am planning on building my own tank and such and was thinking of the plywood type tank since it is the only one in my area that really is cost effective and with the outer stain just looks gorgeous.  The tank won't be too large, 40"Lx20"Hx20"H (about 70 gallons) and I'm wondering what size sump I should incorporate and how I can utilize the sump as a 'fuge at the same time.
<Posted on WWM: http://wetwebmedia.com/refugium.htm
read through the linked files above...>
I'm planning on a FOWLR system by the way.  Is it safe to drill cutouts for overflow boxes on this type of tank or would it be better to utilize my Marineland canister filter to pull the water out and supply the sump and use another pump for the return?  
<Better by far to drill...>
Any idea how much live sand it would take to put a 1.5" or so coat on the bottom?
<Add some, add some more...>
I'm planning on putting around 70-100 pounds of live rock in the tank as well to help the bio load even though I am still unsure of the number and type of fish I will get (my wife and sons just want 'colorful', hehe).  The guy at my LFS sold me a SeaClone 100 skimmer for 50 dollars which seemed like a good deal at the time but now I'm not sure if it will be efficient enough or if I'll be able to incorporate it into the sump/'fuge.
<Keep reading>
Any and all help will be appreciated and thank you again for the wonderful compilation of expertise and data.
Best regards,
Ed
<Please use it. Bob Fenner>

Leaking DIY Plywood Aquarium II - 03/14/06
Hello and thanks for the help!!!!!
<<Very welcome.>>
I finally completed the tank below with your recommendations and so far the tank has been holding water for nearly 3 weeks with no issues!!!
<<Ah, excellent!...am pleased to hear of your success.>>
Now I am starting to think about how I want to stock the tank and have a new set of questions for you.
<<Ok>>
I will probably go with a community FOWLR set up, but I am debating about a marbled cat shark (Atelomycterus macleayi).
<<Mmm...>>
I have heard conflicting reports on size for this fish ranging from 24 inches to 36 inches.  What size should I expect an adult to achieve?
<<According to fishbase.org, this critter reaches a bit more than 27".>>
If it's larger than 24 inches I will not get one.
<<Though your tank is a large volume (512 gallons), at 30" wide it is almost too "narrow" for this animal.  Do keep this in mind when aquascaping the tank and be sure to leave room for the shark to turn around without "banging" in to things.>>
Also I know not to mix cat sharks with large angels but how about pygmy angels?
<<Likely will be fine.>>
Would the shark be any safer with the smaller angels, or would they just end up being a meal for the shark?
<<Though small fish are considered part of the shark’s natural diet, some consider it to only go after sick/dieing or otherwise distressed fish.>>
My LFS tells me this particular shark is safe even with smaller fish as it feeds primarily on crustaceans, but I question that in an aquarium setting.
<<Intuitive of you...yes, aquarium life can influence/change behavior...but in this case, I think most fast moving fishes (like pygmy angels) will be able to avoid the shark.>>
Please let me know your thoughts.  Thanks again!!!
Eric Skikiewicz
<<Anytime... EricR>>

Silastic bead input   3/4/06
This is a follow up to a reader post on his construction of a 300 gallon glass tank with MDF base with fiber glass sheathing. Re: Tank Fabrication   3/3/06 . This is my third posting in a week (I will try not to make a habit of this). I thought my experience may be of some interest and help.
<Thank you for this>
The reader had some trouble with bubbles in the seams. I have seen this in a lot of tanks. Most of the time you can get away with that as silicon holds 300 lbs per square inch. Common practice is just to fit the glass edges together in a similar fashion to working with wood or acrylic. This results in a silicone seal that is not thick enough, and the risk of bubble formation later. I read the directions on a tube of silicone sealant ( Silaflex RTV), and it states…
Extrude sealant into joint. Minimum joint size 5 mm wide x 5 mm deep and maximum joint size 25 mm wide x 10 mm deep
One of the glass and window suppliers here in town went on a conference and one of the topics was how to silicone glass together. He was told the depth of the seam should be about half the thickness of the glass. So a 10 mm glass should have a 5 mm deep seal. This offers a stronger and more flexible seal, and less chance of bubbles.
I have built about 3 all glass and 3 glass/plywood tanks and I have never got any bubbles in the seals doing it this way. Vertical glass panels can be held in place when gluing by cross bracing the corners with strips plywood that has two sided foam adhesive tape on it, and simply pressing them on the top edges, and easily removed later.
Commonly the side panels of the glass are laid on top of the glass base. It may be a better approach to lay the vertical glass panels around the base and allow for a large seal around the edge.
I always pay extra to have the glass flat polished with smooth bevels on the edges. It is safer to work with, and I think essential on tempered glass, as a chip in an edge can cause the panel to explode.
Have Fun
Mike Lomb
<Thank you for this Mike. We have some trouble with some "tray less" queries (yours here is one) that don't have email addresses to respond to... but am hopeful you will find this posted in the dailies, and that others will benefit from your input passed on. Bob Fenner>

DIY Aquarium/Type of Wood   2/26/06
Hi, <Hello Robert> love this site. <Thank you.> Can I use MDF for building a tank or should I use plywood. I intend to build a 300 gallon 24" deep. I know MDF is very dense, and maybe a better choice against bowing?. <Bad idea.  You should use marine grade plywood or furniture grade (both sides good) lined with fiberglass cloth and coat with two part epoxy resin.
Thanks for you time. <You're welcome.  James (Salty Dog)>

DIY Aquarium/Re: Type of wood  - 02/27/06
Ok, thanks for the answer, just curious though, why is MDF not good to use? <Here is a link to a test that was performed with MDF and moisture.  http://search.isp.netscape.com/nsisp/boomframe.jsp?query=MDF+wood&page=1&offset=0&result_url=redir%3Fsrc%3Dwebsearch%26requestId%3Df7c3d960c988040c%26clickedItemRank%3D4%26userQuery%3DMDF%2Bwood%26clickedItemURN%3Dhttp%253A%252F%252Fwww.anu.edu.au%252FForestry%252Fwood%252Fmdf%252Ftoc.html%26invocationType%3D-%26fromPage%3DNSISPBoom%26amp%3BampTest%3D1&remove_url=http%3A%2F%2Fwww.anu.edu.au%2FForestry%2Fwood%2Fmdf%2Ftoc.html  Not saying it wouldn't work, just wouldn't be my choice for a large tank as you are planning.  James (Salty Dog)>
Thanks

DIY plywood glass hybrid tank  - 02/27/06
This is a follow up to a reader's previous submission on advice on a DIY wooden tank. I am not a WWM member (and have no qualifications to be
one), but I have built several wooden tanks before. For what it is worth, here is how I have learned to do it, after making a few of them.
I have added some pictures. There is not a lot on the Net or in books on this. I only use 12 mm marine plywood, not because it is waterproof (it
is not), but because the wood is smooth on both sides, and the veneers in the interior of the sheet are also free of knots. The bottom of the
tank and stand is double thickness. Use fine toothed skill saw blades to cut the wood, and you need know how to use a router. Don't use cheap
router bits; they will fail in no time.
Always use two pot mixes for the paint. Epoxy resin forms a greasy amine bloom on it; you must wash this off with soap before you put another
layer on a dry surface (you can not sand this off). Barbecue scrubbers are best for this, and a degreaser (citrus based). This is a common
oversight. Use stainless steel screws when joining wood together, they do not strip. They will not be exposed anyway; they should be
countersunk in and filled with epoxy. Do not mix epoxy glue in a pot, it will overheat (can actually burn you), and go solid in no time, mix it in flat trays.
You can use steel beams along the length of a tank hidden inside the wood, to add strength and eliminate any need for cross bracing in the middle of a tank. My tank has no bowing at all.  I have integrated the base and the tank into one unit. I lined the tank with 4 mm tempered glass that has a pre-baked black coating on the back. This is normally
used in kitchens, and silicone glued this on the interior walls. You must still finish the inside of the tank with epoxy before this, it will
not stick to wood, and you may have a small leak somewhere and the wood needs protection. You will need a lot of silicone tubes. Sheath the top
edge with epoxy, there will some salt creep here. Make sure there are large ventilation holes on the doors; it can get humid in sump area.
The tank is more expensive that a regular glass only tank, do not do this to save money, you will not. It is very strong though, especially
after 200 screws plus epoxy holding it all together. The tank holds 250 liters water after displacement (350 before displacement) and the sump
holds 100 liters water. For better or worse, that is how I did it. There is nothing in this tank yet, it is still cycling. The sculptures are
concrete; the skimmer is a hang on Deltec MCE 600. Its biology is a work in slow progress. Due to New Zealand quarantine regulations, live rock
is not available (corals and fish are, and they are also quarantined for three weeks on arrival).  <Mike, thanks for sharing with us.   James (Salty Dog)>
Have Fun
Mike Lomb

Tank Fabrication   3/3/06
Dear Crew,
<Gabe>
I have some questions concerning aquarium fabrication. I am constructing a 300 gallon system. This is my first attempt.
<Neat! Quite a project>
I've had some correspondence with Bob and James, unfortunately those emails were discarded and could not be included. The display tank was made with glass sides and a fiberglass bottom. I filled it with water and left it alone for 24 hours. There were no leaks, but...... other problems and concerns have developed. Fiberglass blisters did form in some spots on the tank bottom.
<Trouble...>
I'm fairly sure these are manifestations of my impatience through two shortcuts; not sanding the MDF core prior to laminating, and not wetting the MDF surface prior to laminating. With this said, blistering in the fiberglass is a problem that can inevitably occur, even with better laminating practices. This, of coarse, has me re-evaluating the use of a fiberglass bottom.
<Very glad to read>
Also, there are issues with the silicone adhesion. Air bubbles did form between the glass joints. These range from large bubbles measurable in millimeters, to much smaller bubble clusters that resemble trapped water vapor. These bubbles, depending on location, may occupy from 0 - 95 percent of the surface area in the joints. Most formed after 24 hours of curing and all were completely present by 36 hours of cure time.
<Not so much of a worry here. I have adhered glass and acrylic panels to frames with Silastic... with a "whole bunch" of such bubbles... as long as they were not continuous from in- to outside there were no problems with leaking or the viewing panels "slipping">
The joints appeared bubble-free for 24 hours after fabrication aside for some minor air pockets. This has me very puzzled and I need some input on this.
Here are the facts.
    The glass is un-polished.
<Shouldn't be a factor... except with cutting ones hands, arms... watch out here when handling!>
    The edges were eased with 120 grit.
<No worries>
    The edges are very smooth and even with some minor undulations.
    The edges are fairly square.
<No prob.s>
    The glass surfaces to be joined were cleaned with acetone.
<Good, what I prefer to use (with adequate ventilation)>
    The silicone used was GE Silicone I 100%.
<Good product>
    The silicone was applied liberally.
<Okay>
    The silicone was applied immediately prior to each section of glass limiting any surface skinning.
<How it's done>
    The glass panels were held in place with duck-tape under pressure.
<For this sized system, I prefer to "lay the "tank" on the face/panel that is being installed, lay in the Silastic, place (with help) the viewing panel in the nestled Silicone... wait a day or more for curing, tilt the whole thing upright, and trim the excess>
    Assembly went almost flawlessly and in a timely manner.
    The joints appeared very clear and bubble free for 24 hours.
Why did these bubbles form?
<Mmm, likely some interaction with "dust" from the contact surface, air trapped there migrating>
Is this common?
<Yes>
Could too much silicone be pressed out of the joints causing this scenario?
<Mmm, don't think so>
Could acetone cause this to happen?
<Not if applied a few minutes plus ahead of applying the Silastic... the Acetone "goes away" quickly through evaporation>
What solvents may be recommended for removing silicone, especially from the edges where using a razor may not be so feasible?
<Leave it/this>
I plan to disassemble the tank and start again. Has anyone heard of using a laminate like Formica for the tank bottom. Formica seems like a logical material as it is waterproof and has excellent adhesion with silicone. I understand that glass would be everyone's first choice, but sometimes I would rather be difficult.
Thanks,
Gabriel
<I want to try expressing my concern, lack of ease (again) here with such materials... they are not made to "put up with" the torsional force of so much water height... I would either fashion a very strong "box" of whatever material (a few times past needed strength) that will not, does not show signs of fatigue (in the least) on filling/testing, or revert back to all-glass or all-acrylic here. Please understand my admonition here... tis nothing personal, but a matter of regard for your safety, liability... This amount of water "tearing", getting loose all at once, or slowly can be a huge risk. Bob Fenner>

Glass thickness   2/23/06
Hi Guys and Gals
<Robin>
Please put my mind at rest and tell me my specs are ok!
My tank size is 2500l x 1200w x 800h. I have used 15mm glass
<... about 32" tall and 5/8" thick...>
all round and have placed struts as follows.
On the base I have 2x lengths 2500lx100w. I also have 4xcross struts evenly spaced left to right. These are also 100mm wide.
At the top of the tank I also have the same 2500lx100w struts but my cross struts are 4x 200mm wide as opposed to 100mm.
My front and back overlap the side panels by 15mm each side. Here I have also placed 2x cross struts on either side inside this overlap.
I hope this makes sense to you ?
<I think so>
I was told that 15mm was a little on the thin side for a 2400litre tank but I think the support struts will help carry this ok.
<Is borderline... the volume of the tank is not the real concern/factor... it's the height. If this has been put together "well", and is placed on a "good" stand (level, planar, strong), you should be okay. I would however, practice/fill it outside and leave for a day to test. Bob Fenner>
Please confirm.
Thanks a ton for the advice.
Ian

Double Pane... laminated glass use  - 02/20/06
Dear Crew
<TB>
I was recently at a local shopping mall that has a number of large aquariums on display. One such aquarium is fairly tall ( I would be
inclined to judge it at over 1.2m in height). I was fortunate to observe the maintenance crew working on it at which time I also noticed that it
used fairly thin (approx. 8mm) glass, but that these were double - that is to say, each side of the aquarium was made up of two 8mm pieces of
glass placed flush against each other giving a thickness of 16mm glass.
<Yes>
I am writing to enquire whether you had any information regarding the strength of such a setup, given the considerable price differences
between 8mm and 16mm glass. Presumably this will ensure better insulation, but will it be as strong as 16mm glass?
<Can be considerable... is "laminated" for increased strength>
Also, would it then not be a good idea to use standard glass on the inside, to contain the water, but toughened glass on the outside.
<Mmm, no... not the purpose in this case. A related use of "two panes" is their employment in public aquarium settings... where the "outside" piece is easily scratched (by diamond rings etc.), leaving the inside to work functionally... with a desiccant of some sort in-between to discount condensation>
This would offer the desirable breaking properties of normal glass (in case a small crack should develop) with the toughness of toughened glass?
<Mmm, no... Look up the term "Starphire glass" on the Net>
Thank you for any feedback.
Gratefully,
Tim
<Bob Fenner>

Re: Double Pane  - 2/21/2006
Dear Bob,
<Tim>
I would thank you for your email but for the fact that I now have yet another reason to feel unsatisfied with my current tank - I want Starphire glass!
<Heeee! Is gorgeous... clearer than most all... sparkles>
Surely a tank that has everything including a small price tag and that can hold any and all fish, corals, inverts and other things (living or not) that I can throw at it in perfect equilibrium is not too much to ask for! :o)
Have a great day!
Tim
P.S. I would love to help answer questions - I have read to the point were I feel confident answering all but the most unusual questions! Unconvinced? Ask me...! How can I get involved?
<! Do you have time? Expertise? Obvious to me you care and are proficient in written English. Please do join us. Bob Fenner>

Leak in an epoxy/plywood aquarium  - 01/09/2006
Greetings WWM Crew!
<Salutations!  Sabrina here, but because of a failing with our mail system, not because I know anything about your situation....  I fear I don't have ANY experience with plywood tanks (not so fond of 'em, myself).  Let me explain....  our webmail system occasionally gives us messages that come unaccompanied by the "tray" that includes our buttons for responding.  It seems my particular system - my laptop using Mozilla - is the only one that accurately provides this "tray".  Therefore, you've got me on the horn today. If I'm unable to help, please try responding with a different email service - hopefully it will come through without a hitch.>
I have 3 year old Plywood (coated with Epoxy Paint) and Acrylic viewing panel tank.  It’s 8 feet long by 2 feet tall by 2 ½ feet deep (front to back).  It seems that I have developed a leak almost dead center in the back seam (where the back meets the bottom piece of plywood) of the tank.
<And here we have the reason I don't like plywood tanks.>
It’s not a HUGE leak, but it is an almost constant drip.   
<Yikes.>
Now to discover exactly WHERE this leak was (on the OUTSIDE) of the tank, I had to remove all fish, gravel, water and everything else in the tank.  Then I had to physically MOVE this behemoth so I could look at the backside.
<Now you're talking my language.  Oh.  You meant the tank!  My bad.>
That’s when I found the “leak point’.       
Now I have 2 problems:
1) I have NO clue where the water leak is starting from on the INSIDE of the tank.  Everything LOOKS good, but obviously something is not right. I fear that patching the wrong place will just lead to water rotting my wood from the inside out, so I need to get this thing right the first time.
<The wood has already gotten wet - I fear the wood rotting is perhaps an inevitability at this point - but, mind you, I know little to nothing about plywood tanks.>
2) What method should I use to patch this leak??  
<I plead ignorance.  I would not attempt a patch.  But again, I reiterate, I know little to nothing....>
A) I’ve considered putting a ¼”- ½” layer of Cement to completely cover the bottom of the tank – thus filling my problem.  But I don’t know if cement will “adhere” to the epoxy paint I already have
on there.  
<Neither do I.>
B)  I have also considered using some “Aquamend” by Polymeric Systems Inc to fill the problem area, but once again… I would have to FIND the problem area to fix it.  
<.... and be confidant the fix would be worth your while.>
Can you give me some suggestions??  
<That you consider what it will take in your efforts before you begin to weigh the costs of an acrylic replacement (incredibly pricey compared to a plywood construction, I'm sure) against the costs of time, labour, frustration, etcetera.>
Either in finding the source of the leak or in coating the entire inside bottom to cover the unfound leak.
<For the real answer you seek, please do write back in.  Or, perhaps as Bob posts queries, he might pitch in on this one when it gets posted to the dailies and beyond?>
Soren
<All the best to you,  -Sabrina>

Acrylic and plywood tank - 12/11/2005
Dear Bob,
  I have been reading some of the other posts about large homemade tanks on here and was wondering if you could give me some advice for when it's my turn.  In the future (2-4 years, from what my wife says) I plan on building a 10'x6'x4' tank.
<For aesthetic and functional reasons I would limit the height here to a maximum of three feet>
The tank will be built in my garage.
<Hard to move...>
I was planning on using 1 1/2" acrylic with 1" plywood sides and bottom.  There will be a skeleton fame of 4x4's spaced out every 8"on the sides and every 4" on the bottom.  Then the plywood will be screwed onto the 4x4 frames.  The acrylic front panel will rest directly on a 4x4, sealed of course, with 2x4 framing at the edges as well as the top and bottom perimeters.  Hopefully to give structural rigidity.  I live in San Diego so ground movement is of a slight concern.  Do these plans sound Ok.  Since you live here as well, are there other people that I can contact who has something similar that I can associate with.  Thanks for your input, DEREK
<I also live in SD and have made such tanks... do feel free to re-contact me, perhaps run your ideas through the folks in the local marine and FW fish clubs... some of the folks in retail (Jim at Aquatic Warehouse, Ron at Octopus' Garden). Bob Fenner>

Re: acrylic and plywood tank  12/17/05
Bob, thanks for the reply.  The reason why I want it in the garage is so it
can be turned later down the road when we make the granny flat into our
master bed suite.
<Ahh... I do hope you have a few strong friends!>
I can also install a humidity control if needed.  I
currently have a 560 gal that is 3 ft tall.  Although nice I would like it
to have one more foot of water column.
<Mmm, my/our general "rule of thumb" was that for every foot taller, cost of construction doubles/d>
If the acrylic is thicker and
braced on all for sides and extra bracing on top is it still really that
risky.
<I would go with the 1 1/2" thick acrylic and not worry here>
I talk to Jim and Ron often but not on this matter yet.  BTW do you
know of a place to get the acrylic.
<Yes... there are a few... San Diego Plastics is where I'd look first... Ridout Plastics as well... Do look about, and don't be shy re "making an offer">
  I am pretty set on the 4 ft height so
what thickness do I need, however if it is completely unsafe then I will go
with only 3ft.  Also why do some manufactures make tanks taller than 3 ft if
its not recommended.   Thanks again.
   DEREK
<Mmm, solventing/welding the bottom and top on are far stronger, have much greater structural integrity than just "facing" a sheet on to a frame... Bob Fenner>

DIY Refugium and Mixing Materials - 12/07/2005
I have been pouring over the DIY forums for hours but can't find a definitive answer on the best way to glue acrylic sheets as baffles inside a glass aquarium. 
<Well, you really should stick to one or the other. Acrylic doesn't stick to glass well and there's a significant chance (more likelihood) that they will eventually separate.>
I see several posts that say 100% silicone, and then some that say only use silicone to attach glass to glass.
<Yes, 100% silicone, but I recommend using all one type of material.>
What would you recommend?
<Just what is stated.>
Thanks much, Scott
<You're welcome. - Josh> 

Glass Thickness - 12/01/05
Dear wetwebmedia crew, I'm having a custom made aquarium built and it will have to hold 500 liters of water. (160 cm X 31.5 cm X 90cm) How thick should the glass be to support this amount of water?
<<Firstly...if the person/business building the tank doesn't know, you might be in trouble. That aside...assuming the middle dimension is the tank height (L x H x W), 10mm glass should be sufficient...if the last dimension is the tank height (L x W x H), likely 25mm or greater will be required. EricR>>

Recirculating skimmers, Euro- bracing  11/23/05
Hello Ladies & Gentlemen,
<Peter>
Thank you for your kind attention. Two quick questions, please.  Are Euro- braced tanks stronger structurally than standard braced tanks?
<Good question. I don't know>
Or is it strictly a utilitarian/cosmetic preference? Believe it or not (believe it) LFS give conflicting answers.
<Heee!>
Are recirculating protein skimmers considered more effective than non-recirculating protein skimmers?
<Yes>
The recirculating seams to offer greater dwell time, but non-recirculating pass higher volumes of water.
Which is more effective, please?
<Recirculating>
Compare for example Euroreef CS8-3 models. Recirculating vs. non recirculating.
<Good units...>
Thank you for your expertise and valuable time.
Peter
<There is a dearth of real testing of aquarium gear, but some does exist... though the pet-fish literature is not regularly "picked up" by citation services... One can really only keep reading, communicating on the specialized BB's, attending hobby conferences, and "hope" to run into authors, works re. Bob Fenner> 

Custom aquarium  11/18/05
I was building a floor to wall vi-quarium out of a NEO-ANGLE shower stall.
<Neat!>
It will have a 5 foot waterfall into an aquarium I have designed but have no idea how to go about building.
<Not hard to do... given a few insights... tools and materials>
I am a contractor so I am pretty good at building things and figuring them out once I have the basic concept of how to go about doing it. I hope that you can help me with that. The aquarium I'm thinking needs to be acrylic i
<I... sigh...>
<<Still not finished correcting all, not surprised this is from a contractor.  MH>>
am thinking so that its light weight and stronger than glass but I haven't made a definite decision on that. It will ultimately depend on which is easier to work with. The thing that is going to be the hardest is that this aquarium is not a standard rectangle. It will need to have angled cut edges instead of the standard 90 degrees edge to fit together, unless there is a putty or something i can make angled joints with.
<Please use your spellchecker...>
The dementions
<As in Dr.?>
of this aquarium are going to be 24 inches tall or deep it will be 10 inches front to back, and the shape will be 19 1/2 inches front panel then it will make a 45 (or near 45) degree turn then a 26 inch front panel then another angled turn (same degrees as the first) going into the last panel which is 19 1/2 inches as well. It sounds confusing but if you look at any neo angle shower stall you will see the 3 sided glass and the shape I am trying to replicate you can find a picture and the blue prints for what I am talking about here: http://www.asbcorp.com/product.cfm?prodid=426.  I am basically trying to fit as tight as possible against the 3 glass walls. My questions are as follows: What material should I use glass or acrylic? 
<Either... but if it were me, mine (for my own personal use) I'd go with glass... and Silicone into place>
What kind of glass should I use, tempered?
<Nope, just float>
What kind of acrylic should I use, standard Plexiglas? How thick should the glass be (especially the acrylic to prevent bowing.
<Depends on water depth... likely 1/4" will do here if the water is 16-18 " deep maximum>
How would I make the correct angled cuts instead of the standard score and break 90 degrees cut?
<Can cut acrylic at an angle or even bend, have heat bent... I'd contact Tenecor, other fabricators near you in you go the acrylic route re>
are these special cuts even necessary because I saw a strange custom angled glass tank that had this black putty looking stuff that seemed to be holding it together allowing a good seal regardless of the angle cut or angle the joining panel was turned.( in other words you don't need perfect cuts to butt up just right, the putty filled in spots that weren't butted perfect together. What can I use to cut the glass/Plexiglas. Where can I get the materials needed?
<... see the Yellow Pages... or the Net re...>
What sealer should I use to Finish the corners with? 
<Posted... on WWM>
As you can see I have many questions, but I have been working on this for years and I have all the answers on how to make fake light weight rocks, a mist system lighting and everything else but the aquarium. I finally have the means to make this dream vi-quarium to some true as soon as I figure this last thing out. Thanks for your time,
Matt
<Matt... don't send out emails with poor English... Do learn to/use WWM... the indices, search tool... Your answers and more that you need to know are posted there. Please start here:
http://www.wetwebmedia.com/diytksfaqs.htm and read the linked files above, where you lead yourself... keeping good notes... Bob Fenner> 

Re: Custom aquarium  11/19/05
HA, Thanks
Nice to see you have a sence
<Sense>
of humor.
<Very important...>
Sorry about the spelling there. I searched WWM for an hour or 2 before I Emailed you. but didn't find what I was looking for. I suppose I will check again.
<Please do. Cheers, Bob Fenner> 

Sump water proofing  10/21/05
Aloha,
<And you>    
     Hello, my name is Chris I'm an amateur aquarist in Hawaii.
<Am out at our place this month mauka of Kailua-Kona... in Holualoa>
I have a 240 gallon aquarium that needs a new sump. I have one octopus, six spiny lobster, one Hawaiian reef lobster, three convict tangs, three yellow tangs, one triggerfish, one stripey,
one jack, one barracuda, three sea hares and various other inverts.
<Neat... likely all self-caught>
I'm running a Mag drive 24 for my return which is also used for circulation as well as two power heads. My filtration consists of two homemade fluidized bed filters, two plastic containers filled with blue bonded filter pads and a finer polishing pad at the bottom for mechanical filtration as well as a gallon or so of carbon which I have water flowing through very slowly and finally two Berlin skimmers. Inside the tank I have live rock, live sand, and its filled with real ocean water. The system has been running four months now and my last check revealed unreadable amounts of ammonia, nitrite, and nitrate. (I'm just proud of my set up, doesn't really have anything to do with my question). Basically the stand I made has left me with little room to work with and most commercial sumps will not fit, I've opted to construct my own. I'm really just curious about polyurethane coating. You know the kind they spray on the beds of trucks... rhino lining etc.. Most importantly if this will leach anything dangerous to aquatic life into the water, and if this type of coating would even hold water on a long term basis without cracking or delaminating from the sump walls.
<This material... the sprayed-on type is toxic for quite a while... not really suitable for underwater use... there are many other better choices>
I have already contacted the company with regards to these questions. Although they told me their linings will not crack and would not release any harmful chemicals into the water I really wanted to get a second opinion on this since this really isn't the normal applications these people deal with.
<Take a whiff about the area where they're applied... check the rigs the folks wear while applying...>
I already have a sump I made in use, I coated it in epoxy that I got from aquaticeco.com. It doesn't work well, It has repeatedly cracked time and time again even though I measured the ratios carefully and followed their directions to a tee. On the other hand, acrylic is pretty expensive in comparison to polyurethane coating. This is why I'm exploring other options. Sorry if you guys covered this topic already, I did check but didn't see any info on this subject. Anyway thanks in advance for any advice given and wanted to mention my collection habits. I live right next to the beach and catch all my tank occupants myself. I typically keep them six months or so until I get bored of looking at them, then I release them back into the wild. Am I the only person that does this?
<Mmm, nope... you've got lots of company>
I don't know but works pretty well for me and is so much more fun to get out into the water and catch them yourself! Anyway, great site, the best place to find info. Thanks again.
<I would look into fashioning your custom sump out of "used" glass... a lot of glass places re-sell this... quarter inch/triple-strength will do... you/they can easily cut, drill if you like, and not hard to Silicone together... A hu'i ho! Bob Fenner>
Mahalo nui loa  -Chris

Aluminum and Saltwater 1016/05
Hi, I read on one of your replies that aluminum was not compatible with a saltwater aquarium (i.e. as a support above the aquarium for a light). Is this because the aluminum is toxic to the fish or because the salt corrosion will quickly deteriorate the aluminum? 
<In my opinion, aluminum is fine to use outside of the aquarium and away from water contact. In fact, many commercial lighting fixtures incorporate aluminum. However, contact with salt water will corrode aluminum and aluminum can dissolve into the water and is toxic.>
Also, my aquarium is a 40 gallon FOWLR tank that is only 14" deep and 40" long, and I would like to add an anemone (LT or Sebae) Would a 250w Metal Halide Lamp 6" above the water, along with my 65w 50/50 PC light, be overkill? Thanks for your help, Dustin 
<I would not use more than 175w MH in such a shallow tank. In fact, although I almost recommend halides for anemones, one or two additional PC's would probably do fine in such a shallow tank. Best Regards. AdamC.>