DIYWoodTks

FAQs about DIY Tanks, Sumps Made of Wood

Nice!

Plywood Glass DIY 12/29/12
I was reading through some of the DIY Q and A you guys have and it seems I should just ask if this is a good idea I have in my head. I have an old 55 gal tank, with 1/2 inch think glass,
<Wow! This is an olde one... more recent commercial tanks of this "size" (model...) have been made of 3/8, 1/4, even thinner glass>
that was given to me, that I tried resealing with silicon, and it didn't work. I can see the seam in the corners coming undone.
<Mmm, did you thoroughly cut out, clean the corners ahead of Siliconing? Does this tank have a frame?>
So I thought I might take it apart and reconstruct it using ply wood, but using the four sides of glass to see in at all sides, rather than just one viewing side. I'm a little worried about it all breaking apart if I did that, so I'm asking you guys what you think!
Thanks.
<Well... you don't need the plywood, or any frame to construct a 48 by 13 by 22" aquarium of 1/2" glass... a brace, (Euro if it were up to me) is requisite... I'd keep reading for a while here before settling on a plan of action. Bob Fenner>
Re: Plywood Glass DIY 12/29/12
I did cut and clean the old silicone 2 or 3 times before applying the new stuff.
<... what solvent did you use to clean the glass? Have you read on WWM re such re-siliconing?>
it still had a VERY small leak that ran down one of the seams in the corner. I am quite nervous about re-doing the inner seams of glass, which is why this idea seemed the best to me. But if you think I can do it, could you point me in the right direction (FAQs and the like)? Thanks.
<Ah yes. Please start here: http://www.wetwebmedia.com/glstksilasticf3.htm
If you don't want to follow leads from using the search tool (is on every page)... And the wider Net. Do write back if you have specific questions, concerns. BobF>
Re: Plywood Glass DIY 12/29/12
Yes, I did read here before attempting to re-silicone, and I used acetone.
<About the best...>
It was a very bad leak before hand, and afterwards I did notice a leak for a couple of days.. it was pretty disappointing. Do you suspect I did it wrong, and that I should just try again, or should I break the tank down and redo the inside seams as well? I really appreciate this web site by the way. And thanks again.
<... Does the tank (originally) have a frame? Plastic? Chrome steel/nickel? Did you re-use it/this? B>
Re: Plywood Glass DIY 12/29/12
It has a plastic frame that I didn't remove.
<... I would... and all the Silastic... including twixt the panes, the joints...>
The tank was used for a ball python, and the heat lamp warped the plastic a bit and discolored the silicone (that or old age discolored the silicone).
<All needs to be removed... see WWM re>

Re: Plywood Glass DIY 1/2/12
Happy new year to you! So, I started taking the tank apart and the first pane of glass broke (boo!) - then I had an idea.. could I reassemble the glass I have left, and make a plywood box with holes cut out for the front and sides (with no wood in the corners except the "trim"), and make the
thing 4 inches deeper - giving me about 65 or so gallons to work with - AND I can cutout holes in the bottom of the plywood for a sump! I understand that I'm new at this, so I may have a poor idea on my hands, I was wondering your thoughts. Thanks!
<Ah yes. A nice project. Bob Fenner>

200G Tank - 3/4" plywood construction? 7/9/12
Crew,
<Hi Dave>
Today I brought home a new acrylic tank. It is a used 200G Tall (60" x 24"D x 30"H) tall aquarium, constructed of 3/4" acrylic.
<Nice.>
I purchased it from a reputable Denver aquarium service company, trusting their disclosures and understanding this to be built by a local manufacturer with a strong reputation for quality. The service company stated it was only a few years old, and I thought it checked out as very well built (relying on my research from WWM).
However, in looking at the stand at home, I see it is constructed of 3/4" plywood throughout with wood veneer. It seems there are a few pieces of solid wood on the front of the unit only (top to bottom).
<Not unusual.>
On top of that, we had a rain deluge today, on the way home. The service company delivered the stand on an open truck bed. I wiped it down and pointed a box fan at it for several hours. I don't see any signs of water penetrating the heavy stain coats (and, the stand is lined with PVC on the bottom), and it now seems to be completely dry.
Should I worry?
<No.>
Thanks!
<You're welcome. James (Salty Dog)>
Dave
Re 200G Tank - 3/4" plywood construction? & now stand/level 7/10/12
Salty Dog,
<Dave>
Thank you!
<You're welcome.>
Next question is regarding leveling. I have filled the tank. It is not completely level. I wonder if it needs to be drained and the concrete subfloor leveled before I use it. Here are the differences, with the bottom right corner being the highest water line.
Back right corner: 2.5mm lower.
Front left corner: 4.5mm lower
Back right corner: 6mm lower.
<Mmm, two back right corners with different dimensions?>
I am almost certain there is no twisting. I think there is an uneven grade on the floor which causes the tank to lean slightly forward and right.
<I would measure from the floor up to the top edge of the right front to the left rear and the same with the remaining two corners. That should tell you whether there is a twist or just a front to back or side to side difference. I'm thinking the later.>
Do you think I have an issue? If no, am I just barely within acceptable range? I'd rather be conservative. As I mentioned before, this is a 3/4? acrylic tank 60" L x 30" tall.
<Acrylic is a tad more forgiving than glass so you should be fine here. Is the bottom of the tank entirely
supported by plywood or moisture resistant MDF board?>
Thanks!
<You're welcome. James (Salty Dog)>
Dave
Re 200G Tank - 3/4" plywood construction? 7/10/12
Hi Salty Dog...
<Dave>
<<Mmm, two back right corners with different dimensions?>>
This is a rectangular tank, two back corners have the same dimensions, but my measures seems to confirm that the direction of the slope in the flooring is roughly from the back left corner to the front right corner (diagonal).
<>
I measured the floor, and this roughly confirms the slope, although I guess it is possible the floor itself has some very slight twists (IE, the back right corner measure could be a slight twist in the floor).
<< supported by plywood or moisture resistant MDF board?>>
The stand is built with continuous floor contact on sides/front, and contact planks dispersed along the bottom (if that makes sense, almost like stand bottom studs). So it seems there is good weight distribution in the stand. The tank does sit on top of a sheet of 3/4" plywood (which as I mentioned before, is used throughout the rest of the stand).
Sounds like you are leaning towards my leaving it alone. Does this added info sway you one way or another?
<Mmm, not really. That's less than 1/4" difference in five feet. If it were mine I'd leave be unless
the aesthetics concern you....water level being different at opposite ends.
Best to have checked
this out before you put water in the tank. :-) James (Salty Dog)>
Re 200G Tank - 3/4" plywood construction? 7/11/12
OK, great, I'll leave it. I actually filled it up with freshwater to do the level check (also with lots of vinegar to get off old coralline etc). This is why I'd be slightly less worried about having to fix the leveling. But, any modification comes with risk (such as sending the plane in the wrong direction :o ) so I probably will just leave it!
<Nothing to modify, just a matter of shimming up the stand to true it up.>
Thanks again!
<You're welcome. James (Salty Dog)>

Plywood Tank 4/8/12
Hi,
<Brad>
I'm curious. Instead of plywood why not use industrial grade mdf? This type of material is glass smooth and easy to finish with paint or veneer. For those really big tanks it is available up to 1.125 thick. MDO (sign board) might be a viable option as well.
Thanks,
Brad
<Have found that ply is stronger, marine ply much more water-resistant. Bob Fenner>
Re: Plywood Tank 4/9/12
Thanks! Your input is greatly appreciated:-)
Brad
<As is yours. BobF>

DIY Aquarium, Lg. Acrylic 1/31/11
Hello Crew,
<Hello Tina.>
Once again I am back to ask more questions. I am in the process of designing an aquarium for my husband to build me (He is a carpenter, but never built an aquarium). It's going to be about 350 gallons; the dimensions are 96 long x 36 wide x 24 tall. The design is a bit odd and I have never seen one constructed this way, but I have a couple reasons for it.
<Hmm, I have built a few of similar size and it is very nice! But this is way too big a project for a first aquarium, I do hope he has acrylic experience. I would check around with local clubs or forums to see if there is somebody that has done this before that can assist here.>
To start, the actual aquarium will be constructed from acrylic. I would like your advice on the thickness of the acrylic. I have done a lot of research and found so many different answers for this question. I was
thinking 3/4" inch thick, but I have read people using Â½ inch.
<Definitely the thicker of the two for this dimension. Some would do this in 1/2", but the tank would bow, be quite unsettling.>
I also wanted to know what 'weld on' product number you recommend? I was going to order 'weld on
# 4', but I wanted to make sure before I order it.
<Would be my choice, with some #16 to fill any gaps you may end up with.>
Do the corners of the acrylic have to be bent?
<No, with these dimensions you would be hard pressed to find a sheet large enough anyhow.>
Or, could they just be bonded together with the 'weld on' flat surface to flat surface?
<Yep.>
Can I spray paint the back and two sides of the outside of the acrylic? If so, what paint do you recommend?

The top acrylic will be 4' around the top, and 3.... 4' braces going front to back. Should this
all be one piece? Or, can it be done with scrap pieces?
<It can be done with scraps, but one whole piece with a large radius in each corner is better. With the scrapes you end up with 90 degree corners where the supports meet. That is a high stress point and can lead to failure.>
Now the odd part is I have designed a 3/4' plywood frame for the bottom, 1/2' plywood for the complete back and both sides. The front will be framed 4' all around. The plywood will have 2x4 beams vertically every 12' and horizontally will have a 2x4 top and bottom beam. They will be glued, nailed and have metal brackets. Installed on the outside of the beams will be a decorative painted wood.
<Are you talking of framing around the aquarium or under it? If around I would really take a look on the net for plywood tanks with just an acrylic or glass viewing panel.>
Should the beams be closer?
<Every 12" is more than enough.>
Is the thickness of the plywood going to support the acrylic any better? Or will there be a problem? Would you recommend thicker plywood?
<The thicknesses you list will be fine.>
Should I put something between the acrylic and the plywood?
I was thinking of using foam insulation, would that be ok to use?
<Is exactly what to use, the rigid Styrofoam type.>
What would be the safest paint to use on the exterior wood? I wanted to use interior latex paint, but I want to make sure it will be safe.
<Just fine.>
This aquarium will be on the first floor in my home. My husband is going to reinforce the floor by framing support beams in the basement under the tank. The tank stand will also be built by my husband.
<Ah, so I do take the above regards framing around the tank. With the dimensions you list and the thicker acrylic there will be no need. If you are going to frame it in I would simply go with thicker plywood all around and search the net re plywood tanks.>
I am not sure where to start with the stand, my husband was thinking of framing it with 2x4 every 6', would that be suitable?
<It will more than enough. No need for every 6".>
If so, should he do that throughout the whole inside of the stand?
<No, but would be beneficial to have some cross beams at the top to support the plywood in the middle.>
Or, what would you recommend?
<Take a look at the tank and stand calculators on GARF.org. I don't agree with it all, for instance it will recommend 1/2" for your tank because it is 24" tall (there are other factors), but it will give you the basic idea on assembly and stand construction.>
I hope you can understand my aquarium design. I am hoping the plywood will make it sturdier.

Thank you
Tina
<Welcome, Scott V.>
Re: DIY Aquarium, lg. acrylic, plywood now 1/31/11
Hello Scott V,
<Hello again!>
Thank you for your quick response.
<Happy to help.>
You have made it very clear that this is too big of a project for the first timer.

I assume you mean the acrylic tank, and the plywood tank of this size would be safer for a first
timer.
<I don't like these tanks, is just my personal taste, but they have become very popular due to cost and ease of fabrication IMO. Especially with your husband's background, I really think this is more appropriate.>
I originally wanted to do the plywood tank, but I was worrying that it may not work. My biggest concern is my fish being safe.
<They work great. In some ways (especially if fiberglass reinforcement is used) they can be much more durable.>
My husband was going to practice some with the acrylic, but if you think our best bet would be the plywood tank. Then that's what I will have him do, I am going to do more research on plywood aquariums, but I still would like your opinion on a few things.
<Sure. I can tell you as somebody that has done acrylic work for many years now, I am still hesitant to take on big projects like this. There is just too much stuff you do not learn until it is too late. People look at the cost of Acrylic and the "ease" of fabricating. This leads to many "I built it myself" type stories in the forums. Well, let us wait and see.>
If we do the same dimensions 96'L x 36'W x 24'T, what type of plywood? Will 3/4' plywood with the framing I explained in the last email work fine?
<Yes.>
I read DIY aquariums on GARF.org, it shows to put glass in the plywood tank to use aquarium silicone; will that work if I use a sheet of acrylic?
<It will. Really silicone does not form a mechanical bond of any significance with plywood, marine resin or acrylic. It is merely a sealant. Water pressure holds it in place. For my money I would go glass for a viewing panel here. Cheaper, more scratch resistant and the problem with glass (edges and precise dimensions relying on others) does not really come into play here. That is unless you suspect you will have Babe Ruth in there swinging something.>
If not, what should I use to bond the acrylic to the plywood and have no leaks. That site also said for my size to use 1/2' glass, does that also go for the acrylic or do you still suggest the 3/4'? GARF.org gave some great information on the proper epoxy to use that will be safe for my fish.
<Oh yes, the calculator is great for this stuff. With both acrylic and glass (there is a plywood with acrylic choice) they recommend 1/2". I would go with that for glass, but still 3/4" for my taste in acrylic. Fact is minimum acrylic thicknesses, while they do work fine, will bow out in the middle and look unsightly. It kills me to constantly read from manufacturers of acrylic tanks that acrylic has less distortion than glass, then they build it out of a thickness that makes it look like you are viewing your tank from a globe type fishbowl. But again, that is just my opinion, I hate bowed and wave front tanks for the same reason. I refuse to own or install those. People ask me to and I say no. Few are happy with them, even far fewer buy the same again.>
Are plywood aquariums dependable?
<Yes, very much so when constructed properly. With a carpentry background your husband should be more than capable. The waterproof in mostly just a bit of busy work!>
How long do they usually last? Should the epoxy be reapplied every so many years? Or, is it durable for
a long time? In your opinion, how safe are plywood aquariums?
<To all of the above, I really have no issue, nor have seen any, so long as the look is what you want. I just personally like the whole front at the least opened up for viewing. If a "viewing window" is a look you like I would not hesitate a bit to do this.>
Thank you so much for your time,
Tina
<Welcome!>
Re DIY Aquarium, Lg. Acrylic 1/31/11
Hi Scott,
I might add that Marc Levenson has a tremendous amount of information on his site as to working with acrylic.
http://www.melevsreef.com/allmysumps.html
James

DIY tank, ply, glass 2/22/10
Hi guys, I'm building a large plywood tank for my living room wall. The tank will be 3x3x10 foot.
<Mmmm>
In regards to the front glass panel, do I have to use a single piece of glass, or can I silicone to 5ft pieces together?
<Better to have one piece... it's very hard to make a frame that can/will support two pieces at this height, run>
If I can use the second option, I plan to place three 2x4's vertically down the front. This should hide the seem and help with any bowing that may occur. Any help on this would be great, thanks
<This won't work. And the danger from catastrophic failure here is too great to not warn you to the extreme. Get some help engineering wise here.
Bob Fenner>

Plywood / glass marine aquarium 11/4/09
Hi guys (and gals ?)
1st off, hats of to you all !
<Need mine on this AM... cold>
My history with fish:
I used to keep freshwater (mostly tropical) fish whilst living in South Africa. The most amount of water I ever had in various tanks was a total of about 3000lt, including a home-built 2,4m X 0,6m X 0,6m discus tank, home built hexagonal tank (on the floor of the lounge) with a diameter of 1,2m and a height of 0,7m, and a number of smaller tanks (built and bought). I had tanks in every room of the apartment except the shower and kitchen.
<Neat!>
That said, I am now in Greece, and wish to build a tank in a house. a Marine tank ( ending up with a reef system ). I have read a lot on GARF and even more on your site, as well as many others. Sadly there is a fair amount of incomplete or misleading information out there, as I am sure you are more than well aware of.
<Yes>
I am very much a hands-on person, and wish to build as much as possible myself, as cheaply as possible to have as much money as possible for good equipment (pumps, lights etc), and of course, tank INHABITANTS.
I found a very useful glass-thickness calculator (on the web) for aquarium glass made from float glass. This I would use for my viewing pane(s). The rest would be made from 1" plywood, or thicker if you so recommend. Before i can even ask the question about single or multi-pane viewing glass, I have a
question that I have not been able to find an answer to: What is a good depth for a reef aquarium ?
<Functionally " a couple of feet ", aesthetically... depends on the length and setting and "tastes" of the apprecionists>
Everything I have been able to find at this stage says something along the lines of " If you have a deep reef, you will need MH and VHO lighting " etc. But how deep is deep ?
<A water depth of more than 24" or so...>
I want to keep away from MH for a number of reasons, 1: the cost of electricity here on an island, 2: the heat. (and the associated cost of dissipating that heat from both the room and the water) Lumens per gallon calculations have not answered this question to me and my understanding of water. During construction I will be putting in a few ledges to raise any species requiring a great deal of light.
<Yes... and with substrate added, likely 18-20" of water to penetrate.>
Another question at this stage of conceptualisation: Is there and structural problem with having 3 X 1m viewing panes as opposed to 1 X 3m pane ? I envision a 'window' like effect.
<Have seen this, these... I prefer the one panel>
Essentially there would be 3 tanks separated with 1" plywood (with a number of 150mm diameter holes cut
through) all running off 1 under tank sump / skimmer / nitrate reactor etc, with power-heads in each 'tank' for flow within the tank to avoid dead water. With a water height of 800mm, and a bending strength of 19,3 N/mm2 (the lowest figure quoted by reputable glass suppliers), a safety factor of 2.44 is obtained with 13mm float glass using the 3 panes, and only 1.7 with a single pane, which is too low for me.

I have seen safety margins of both 3,8 and 2,5 used on various forums / BB's etc. Would 2,44 (in your honest opinion) by adequate ?
<Yes>
At this point I am still doing research into what I would need, (and compiling a list) and will only start construction of the supporting structure and tank once i have acquired enough equipment to start. This
may take a good few months yet.
<Anticipation is fun, enlivening>
Some (at this point academic) questions about tank inhabitants. With careful packing, how long can 'beginner to intermediate' tank inhabitants be expected to survive in transit ?
<In transit? A day or so with oxygen...>
Live sand / rock. I live ON the coast, when not living on the sea itself.
There is no real industry near by, and defiantly no heavy industry for more than 60NM from here - and even that is light compared to refineries and motor vehicle manufacture. The ocean is crystal clear (Yes, i know a bad sign) and therefore not much plankton. However the rocks are covered in all sorts of growing stuff. Would it be ill-advised to use some to seed the aquariums rocks and formations ?
<Mmm, not if you intend to keep local life altogether, no>
I will be making some formations myself (thanks again to GARF and About(dot) com) . Live sand. Can I just collect a good number of buckets from various beaches here and use that as my sand bed ?
<If you'd like. Will certainly be interesting; and a work-out>
Many thanks to all the information already available and any advise I get.
When I actually get started I will keep you updated, as well (I am sure) have yet more questions.
Best wishes
Jonathan
<And you. Bob Fenner>

Saltwater OK With Fiberglass Sealant For DIY Plywood Tank Build/DIY Wood Tanks 10/14/09
Hello
<Hello Josh>
I was looking to do a 1000 gallon plywood tank build and as I look online and read about it I only see these type tanks in a freshwater application.
Can you use these tanks for saltwater?
<Sure.>
Is the fiberglass used ok with saltwater or is there an adverse reaction.
<Need to be careful in choosing the resin. Some are designed for marine use with algae
repellents incorporated into the resin. I would also use woven fiberglass cloth in all corners for added reinforcement, preferably, at least 9 ounce cloth.>
I thinking not but i truly haven't seen one yet in a saltwater application.
Thank you so much and keep up the awesome work.

P.S. What are the differences in Fenner's old and newer book? Is it just a second run?

Saltwater ok with fiberglass sealant for diy plywood tank build 10/14/09
Hello
<G'morrow>
I was looking to do a 1000 gallon plywood tank build and as I look online and read about it I only see these type tanks in a freshwater application.
Can you use these tanks for saltwater?
<Indeed you can>
Is the fiberglass used ok with saltwater or is there an adverse reaction.
<No. Once the resin is cured, the fiberglass covered... No worries. Have done this myself, seen it in place many times>
I thinking not but i truly haven't seen one yet in a saltwater application.
Thank you so much and keep up the awesome work.
P.S. What are the differences in Fenner's old and newer book? Is it just a second run?
<Is largely re-written (and needed it!); the original I finished in late 1995... Many improvements in the field, and choices in livestock... peruse both copies and you'll immediately get the gist of what I state. Bob Fenner>

Plywood and Acrylic DIY 8/2/08 Hi there! <Hello> Have mulling over the possibility of a rather large 96L x 36H x 36D plywood tank which would be framed out like a house: 2x6 walls 1 foot on center with 2x12 for stand also on 1 foot center. The inside would be sheathed in 3/4 ply. <For the cost/future stability, 1' ply would be more suitable.> The trouble I'm having is in resolving the acrylic front, the tank will be put together exactly like an all glass aquarium sides inside of front and back all of that sat on top of the bottom. All of this will be, as stated before, framed out with lumber. The inside (maybe the outside as well) will be sealed with two part epoxy How do you suggest sealing the acrylic to the plywood, I have read of painting the epoxy onto the acrylic there by giving silicone something to adhere to, but short of bolting which if rather not do for visual cleanliness any suggestions? <Skip sealing the acrylic with epoxy, acrylic is basically epoxy! Placing it inside the ply frame with silicone will be fine. I would use at least 1', if not thicker (1 Â¼') acrylic for this height/run.> Any and all help would be appreciated <Welcome, Scott V.> <<RMF would like to kibbitz here a bit, basically offer what is possibly unnecessary/already known... just to make sure he understands that you understand that the tank corners really need to be securely screwed together... and that I'd use fiberglass tape in all the corners...>>

Re: Plywood and Acrylic DIY 8/3/08 Thank you for your response, <My pleasure.> I just want to make sure I understand before taking on such a large amount of water, in my design with doubled 2x4's top and bottom (leaving a 30" x 93" opening) would suggest silicone inside (any special preparation i.e. Sanding) and then go with at least 1" acrylic? <You can sand the bonding area of the acrylic for a bit more stiction if you like, this is still a weak bond no matter what. The silicone will merely serve as a gasket more than anything, with the water actually holding the acrylic in place against the ply. Be sure to do all of this after the ply has been epoxied/glassed/sealed.> What thickness glass would you think appropriate? <3/4', Scott V.>

Re: Plywood tanks, an experience builder chimes in with useful input 8/04/08 I look at this site most days, and have sent questions over the years with consistently helpful advice (so thanks to the crew). For what it is worth I wanted to offer some input to a question recently posted by someone who is building a very large plywood epoxy lined aquarium with an acrylic front panel using silicone glue to gasket this against the front viewing frame. I think the choice of acrylic in this project was for the strength. "Re: Plywood and Acrylic DIY 8/3/08 I just want to make sure I understand before taking on such a large amount of water, in my design with doubled 2x4's top and bottom (leaving a 30" x 93" opening) would suggest silicone inside (any special preparation i.e. Sanding) and then go with at least 1" acrylic?" Here is may take on this. I have built several plywood tanks, and lined them with tempered glass. The plywood needs a coating of epoxy (silicone does not bond well to bare wood). The opaque walls can be lined with 4 mm tempered glass with color baked on the back. This is used in kitchens. You will have the insulation and strength of the plywood with a permanent color that can not come off, and a strong silicone seal. You can have predetermined holes drilled before hand if you wish. The front panel can be low iron glass, called sapphire glass, and it is as clear as acrylic. Tempered glass has 5 times the strength of regular glass. There is a table from a New Zealand site that has done the calculations based on height and width using standard glass. http://www.fnzas.org.nz/articles/technical/common_sized_aquaria/ The largest tank in their table is 2030 X 830 mm (90 inches x 32 inches) where they recommend a minimum of 2 cm (3/4 inch). Now if that was tempered, it increases the strength by a factor of 5, so even 1 cm would be enough. Height influences thickness more than width. I epoxied steel beams 5 mm x 30 mm in the top horizontal frame in the wood, and there is no flex or bowing at all a 120 mm tank. The silicone would form a very strong bond (300 lbs per square inch in think), so a one cm boarder is just not going to leak. You will need large tubes of silicone. <Yes... "caulking gun" size> Yes glass is heavier, but in would contribute little extra weight compared to the total weight of the entire tank once water and rocks are in it, and will not scratch as easily. However even tempered glass is not scratch proof. I thought this may be a better approach in a project of this type. Please correct me I am wrong in some way. I just don't think acrylic is the best choice here. Mike Lomb <I too have built many plywood tanks... for myself, wholesale and public displays... always with glass for the viewing panels... as it was cheaper by far, more readily available, and the best service for the intended function. Again, my thanks for your sharing. Will post near the existing querior's mail, share with ScottV who had/has been corresponding with. Bob Fenner>

Plywood Tank 224 gallons 3/8/07 Hello first off I love your site. An Invaluable Resource! <Thank you, good to hear you find it so useful!> I am planning on building my dream aquarium. It shall be fresh water with plenty of DIY involved. <Nice, it is always fun and rewarding to build yourself.> I am just having problems with the plans. Essentially I have drawn up some plans on GARF.com and this is what they gave me. <OK> Tank Information: Material = Plywood w/ Glass Tank Height = 24" Tank Width = 30" Tank Length = 72 " Plywood w/ Glass Thickness = 3/4" Approximate Gallons = 224 I plan on switching out the 3/4 inch plywood for 1 inc. They say 3/8 glass in front I am going to go with 1/2. <Smart move, the little increase in cost does not even start to compare to the huge benefits of going with thicker materials.> Now I have a couple of questions. Plumbing / Resin First off the plywood shall be sealed with fiber glass resin. Would I be ok using regular latex paint with 5 coats of resin fiber glass on top? Or would it be better to mix a pigment into the first layer of resin and keep applying regular resin after? <A better choice, the way to go here. The pigment in the last layer or two will give you the best finished color.> Will my Resin Have trouble sticking on top of paint? <It will stick to the paint, the question is how well will the paint stick to the wood? Not nearly as well as the resin.> If any of this seems like a bad idea I shall just keep the tank "wood looking" on the inside. There is no 2 part epoxy paint that is available to me easily/cheaply. <The pigment in the resin will work fine.> I plan on making two corner over flows. They shall be constructed with plywood to match my decor. Use the same system for overflows as for tank. 5 to 6 coats of resin and fiber glass. Should my over flows come out the bottom of the tank or the back? <This just depends on what you need to accommodate your setup plans, it will make no functional difference.> How many GPH (Gallons Per Hour) am I shooting for ? 2240gph? <This will be quite a bit of flow through a sump, but manageable through a 55.> How many over flows and what size would that equivocate to, 1 inc? <Hmm, I would use three or four 1 Â½' or a pair of 2' drain lines for this flow.> How many return lines (1,,,1inc?). <Two 1' or three Â¾'. About half a dozen if you go with Â½'> The return shall be plumbed into a spry bar, which shall sit above the water line in case of pump failure. My sump will be about 3/4 feet of head away from the tank and shall be 55 gallons. When drilling and installing bulk heads it is said to get the parts before you drill to check sizes. <Yes, I would.> Ok then what drill thru my resin install my bulk head then re resin around it? Or Drill , Resin two/tree coats on the inside of freshly cut hole, and then squeeze my bulk heads back in? <Simply drill the tank after it is finished. You can then install the bulkheads with the flange and gasket inside the tank in this case. I smear of silicone will make sure the gasket seals against the resin coating inside the tank.> I just can't figure out how many drain lines and return lines. Slightly Confused. lol. If I use over flow chambers inside the tank, I am filtering my surface water. Ok but if I put a Drain/ Bulk head 1/2 way down the back of the aquarium and my pump fails, I will drain 1/2 my tank onto the floor. <The potential for a leak is good reason to drill your drains higher up in the tank. This will not be a problem if the overflow boxes are 100% water tight.> Not good ok but I don't want to filter my surface water 10 times an hour and not filter the middle to lower 1/2 of tank. Any Input would be great. <The circulation from the return will mix it all up, you will be filtering the entire tank.> The sump still needs to have the plans drawn up. But I am planning a Trickles tower , mechanical filtration, heater, refugium. Mag 10 pump. Flexible return tubing. Just to keep it all out of my tank. <Sounds good.> Oh yeah, I plan on using 1 thin sheet of plexi glass on the bottom to protect my finish from rocks etc. . And perhaps 6 in along the sides and back walls. Don't want my rocks poking a holes in the resin and joining the soggy socks club. That is ok providing I silicone it on right? <Yes, no problem.> Once again you guys are an invaluable resource! <Thank you for the kind words Shane.> Looking forward to hearing your suggestions. Thank you ever so much Shane. <Welcome, let us know how it all comes out, Scott V.>

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>>

DIY Plywood tank Finally, I found someone to answer a couple of questions. I want to build a 180 gallon plywood aquarium and have bought 3/4 inch plywood for the frame, but the tank height is 24 inches, width is 24 inches and length is 72 inches. <Mmm, I'd trade in the three-quarter for one inch ply... much less bowing> Not sure of the proper cutting measurements for exact fit for the lighting <Mmm, what? Light fixtures will likely be four feet in length if fluorescents are used... you could overlap these> and to order the glass which I think is 3/4 inch thick, right? <Glass or acrylic, with how much "edge" to it? That is, the border wood that you will cut out for fitting the viewing panel? Likely four inches or so... you could use half inch> It should weigh 2100 lbs. But before I put the epoxy coating on can I use a wood filler that is all season durability with one fill application for no shrinkage, stains and sands will accept screws and is water and mildew resistant. It is made by Lepage. Then can I put an epoxy coating over it. Or will this be poisonous to my fish. <The label should state yes/no... there are epoxies that are entirely safe once cured> The 4 by 8 sheet is still in my living room and I need to get it cut to the proper dimensions very soon or I will be sleeping in the dog house. <Trade it in!> I never built one before and I can only get cutting dimensions for the 140 gallon aquarium. <Uhh, draw all out in paper... make the two side panels fit inside... have top pieces (four) fit on top of the bottom... how about braces? I would run two pieces... four inches thick, on the inside near top (down a couple of inches) on the front and back...> I will need a stand to put this thing on somewhere and all the ideas for the pumps and everything to go with it. <Either get some help here... four by four wood and carriage bolts or welded metal... powder coated...> I am not very computer oriented so if you could help me get this built it would save me on building a bigger doghouse. Thanks. ASAP please respond! <Read through Ozreef.org for much more DIY input here. Bob Fenner>

Live Rock Curing/Holding System <Hello, Ryan with you today.> I'm thinking about importing live rock for resale and I need info. on the best way to keep the rock. I would like to build my own holding tanks. <Before I get into your query- Please do your best to take time and use proper grammar and punctuation. After all, these are posted for aquarists to read, take note of, and search within.> I'm thinking about two tanks 8'x8'x18''to 24'' deep made out of marine grade plywood and epoxy coated. One tank for curing and one for the cured rock. What is the best way to heat the tanks? I know I'm going to need some big skimmers, lots of sand, saltwater and some good MH lighting. I have a 2000sf. building to house this in so I have plenty of room. Any help with lighting/filtration/heating would help out greatly. <Ed, the best thing you could do at this point is go out and grab a copy of the Book of Coral Propagation, by Anthony Calfo. It's the best layman's guide to building these types of systems that I have seen. 20 bucks on the book is a drop in bucket if you nail this system on the head. This is a pretty serious setup you're talking about, and I don't believe that a quick paragraph of answers from me will suffice! Good luck, Ryan>

DIY large tank, system plans Hi: <Hello there> I would like to build a tank out of glass and plywood that measures approximately 132" length x 36" deep x 48" high. I have been trying to locate DIY plans for a similar sized tank in the 1000 gallon range, but have been unsuccessful. Do you know where I can find plans, or anyone who will draft custom plans to my specifications? <Mmm, nope... have seen ads for such plans in hobby magazines over the years... in the back, classifieds... You could easily piece together what's involved from a cursory reading of WWM, other sites... The height is a bit of an issue... I encourage you to consider switching the width dimension... make the system three feet tall, four feet wide... to save on the viewing panel cost, make it easier to work on, in> I am quite capable of building a tank myself, but I do not have the engineering knowledge required to design such a tank. Thank you in advance for any assistance you can provide. Rob Koblasz <What aspect/s are you wanting input on? Width of materials, modes of construction? Plumbing, filtration? Gear? Bob Fenner>

Re: DIY plans Bob: <Rob> Thank you for both your time and reply. I guess I have quite a few questions relating to both the materials and the mode of construction. Is it better to use glass or acrylic, and how thick should it be? <Either might well be preferable in different settings... likely the glass will be less at the shorter height, the acrylic easier to work with (much, much lighter), but scratch and bow more easily...> As for the plywood, is 1" marine plywood sufficient? <If braced, screwed every four inches, fiberglass strip and resined in the corners, for the three foot height, yes> Is steel reinforcement necessary for the dimensions I would like? <No> I have an acquaintance with 2000 gallon tank that is 20' in length which was built with steel reinforcement every 2', but I do not know if it is necessary for the tank that I want to build. <Not necessary, but advised... especially in an area subject to ground movement...> I have researched your site and others as you suggest regarding DIY tank projects and I do have a rough idea how to do this. With regard to the height of the tank and the changes you suggest, are there any structural concerns, or just cost and ease of maintenance? <Quite a few structural concerns... know that for every foot of height such projects about double in cost... in materials> I believe taller tanks are great for viewing, and floor space might be a concern with the extra foot of width. <Mmm, I'd do this... make a "cardboard mock-up of the shape/size of the proposed system/s... the three and four foot width/height dimensions, and stand it up in the proposed space... the three foot tall one is very likely the route you want to go...> I sincerely appreciate any additional information you can provide as I do not want to make a mistake I will regret when the tank is full. It makes for a much happier wife when the water remains in the tank. Thanks Rob Koblasz

DIY tank ? 7/2/07 Hello again! Back with another question! I am considering building my own reef tank. Mainly for practice, I want to build a very large tank in the future. The tank will be 24 wide, 30 long, and 24 deep. Plywood and glass construction. My question is the inside of the plywood. I have a lot of left over rubber pond liner and am wondering if this can be used. <Can, but I wouldn't...> The aquarium sealant I have says that it will adhere to some rubbers. <Not well, or long enough to suit me> If I put the pieces to fit and over hang each cut piece of plywood and set in place before screwing the pieces together. Would it work sealing the corners and glass with 100% silicone? My other option would be plexi glass. Can I seal the tank with silicone? <Mmm, not with Plexiglas, no...> Obviously, the silicone will have no structural use, only to seal the tank. <Mmm, too likely the seams will bend too much...> I really don't want to go through painting the tank and worry about scratching through the epoxy over time. I have used the rubber liner in a pond tank made out of plywood and am very impressed with its strength. Please let me know what you think! Thanks again! Rob <Well, perhaps worth experimenting... the viewing panel/s can indeed be Siliconed over the EPDM/Rubber liner... this needs to be cut loose enough to fit all inside surfaces... Shades of del Rosario's tanks coming apart in the nineties! BobF, who wishes he too were "what was old is new again" this AM> Tempered glass for aquariums Hi bob: I have been playing with marine aquariums for about 30 years and still love em. I have decided to build a 300 gallon tank 96Lx24wide 30 tall. Bottom, sides, and back are 3/4 plywood backed by 2x4 framing on 12 inch centers. the inside of the tank will be covered with a couple of layers of glass mat and polyester resin. The corners will receive an additional strip. A light blue tinting resin will added to the mix. The question I have is the age old glass thickness one. calculations say 3/4 is the correct size. Would 1/2 inch tempered glass work? <Mmm, yes... if supported all the way around so itself wasn't the structure resisting bowing> it still about $100.00 cheaper than 3/4 inch. Could I use 2- 1/2 inch pieces sandwiched together still cheaper than 3/4? <No> And yes the top of the tank will be connected every 2 feet. Your thoughts on this will be appreciated R. Luckert <If it were me I'd spend the extra hundred dollars for 3/4". Bob Fenner>

How thick is thick enough? (custom tank construction) Hi, I have read hours of great ...GREAT info on this site!. I am building My own tank and I plan to start next week. It will be plywood and acrylic (Plexiglas) the dimensions I would like to build will be 96" long x 24" deep x 48" Tall, I have priced all of the items to include the very hefty 1" thick sheet of Plexiglas.... BUT?? will 1 inch of thickness be ok? also will 1" thick plywood be enough? The rest I can Handle through the outstanding idea's and instructions in your site, Thank you very much, Sincerely, Michael Waszak <Mmm, well... if this tank's viewing panel were braced all the way around it would do, but likely bow too much (to suit me)... I would increase the thickness of the plexi and paneling if it will fit your budget. Bob Fenner>

Re: How thick is thick enough? Thanks bob, I have decided to change the tank size to officially, 96x18x48. with the 4x8 foot plexi @ 1" thick. do you believe that the glass and 1 inch plywood wood with these dimensions would cut down on the bowing? <These are the same dimensions as listed before (for the building materials)... the width (L X W X H) is not important here... the depth is. The "answer/response" is the same)> ( the master plan here is really a compromise, My wife Loves LONG! and I've always wanted a tall tank....) She plans on lots of smaller schooling fish. fish turning wouldn't be an issue (depth)......another question i guess would be should I drop down to 96X12x48? i really appreciate the time you give to help people like myself. I will send you a finished pic or 10 :-) oh yeah..It will be braced all the way around! <I think we/I am confused here... the middle dimension you list is the height? You can easily have this tank three feet (36" in height made of these materials with little detectable bowing, risk of structural failure. Bob Fenner> WHAT WE ALREADY DISCUSSED~ Hi, I have read hours of great ...GREAT info on this site!. I am building My own tank and I plan to start next week. It will be plywood and acrylic (Plexiglas) the dimensions I would like to build will be 96" long x 24" deep x 48" Tall, I have priced all of the items to include the very hefty 1" thick sheet of Plexiglas.... BUT?? will 1 inch of thickness be ok? also will 1" thick plywood be enough? The rest I can Handle through the outstanding idea's and instructions in your site, Thank you very much, Sincerely, Michael Waszak <Mmm, well... if this tank's viewing panel were braced all the way around it would do, but likely bow too much (to suit me)... I would increase the thickness of the plexi and paneling if it will fit your budget. Bob Fenner>

Building DIY Tanks Hello there: I am planning of building a plywood tank around 400 gallon, my dimension would be 84" long 30" large and 36 "tall , I would use 3/4 plywood with 1/2 glass or 1 "acrylic. I also would also paint the plywood with epoxy paint that i find at my local pool dealer (would that be ok) And also for extra protection I would had plexi-glass on all the epoxy paint and the plywood to protect against scratches and leaks . Would use GE silicone 100% pure or GE silicone for aquarium uses, are they the same because the 100% pure is a little bit cheaper! How is this sound for now???? And also because the acrylic seems to be a little cheaper ,is it better than the glass and would it stay with only silicone to attach it to the wood -epoxy paint? And were can we usually find acrylic sheet? Thank you very much for your help <Ahh....much to learn and much planning required here. 400 gallons is a heck of a lot of water, best to pick one system or another, either ply with attendant support, sealants, epoxies, glass or acrylic face, or all acrylic or glass. Price is only one consideration of many necessary to be successful here. Please do search at WetWebMedia.com for DIY information on building your own aquarium. I also highly recommend a good reference or two on this particular subject and the tech sheets for any materials you might choose so you know the proper thickness/tolerance for this much water in this particular dimension. My best advice, don't decide solely on price or cut corners in materials or information. Get all your info, decide on which is best based on need, cost, ease of use, etc. Then build according to plan. Best of luck, Craig>

Tank Construction Greetings from Arizona, <Hello from sunny Southern Cal.> I've searched the net high and low, and I still feel "lacking", perhaps you could answer this question for me. Can Acrylic be "bonded" or make a water tight seal with Plywood? (can I use screws/bolts in the acrylic?) <Mmm, not "bonded" at the molecular level as in melded to other sheets, but can be drilled, bolted, nestled in a bed of silicone... best on a flat panel with a cut out if using wood for the structural component> Here's my situation - I'm constructing a Plywood Tank and I want to insert either an Acrylic or Glass front. Current Dimension - 96"L x 30" W x 24" H (approx 299 Gallons) Plywood Thickness - 3/4" AC Grade Plywood Glass Thickness (IF USED) - 1/2" Plate Acrylic Thickness (IF USED) - 1" (do you think I could go THINNER HERE??) <Mmm, half inch would bow too much for my liking, appearances... 3/4" should be fine... if supported all along the face of the viewing panel> Waterproofing Agent for Plywood - Epoxy Paint Waterproofing Agent for Glass to Wood - 100% pure Silicon<e> Waterproofing Agent for Acrylic to Wood - 100% pure Silicon?? <Yes, 100% silicone sealant> I'm still in the planning stages, but I want to make the "right" choices the FIRST time. I know the differences between Glass/Acrylic and I think I would rather use Acrylic in this situation, but COST is a factor and so is the "waterproofing issue". Ohhh one last comment/question. IF I use acrylic, would you recommend that I attach a sheet of Acrylic or Wood (maybe 3"-4" wide) running the length of the tank on TOP of the Front of the tank for added support for the Acrylic front?? <A good idea, yes, drilled, screwed about every four inches... and such a brace on the back, inside sides as well.> Thank you in advance for any advice you might give!! Soren <Please contact me if you have further questions, concerns. Bob Fenner>

Tank building questions Hello - First let me say that you site is packed with great info. I have been reading it for days. <Wow! Glad you find WWM of use> I like keeping large fish, and they require large tanks. I have built several on my own using 2 part epoxy floor paint over 3/4 plywood and sealed 1/2" glass to the front with 100% silicone (usually GE door and window - never kitchen and bath as it is mildew resistant). <Neat, good for you> Glass has become hard for me to get a decent price so I have been working with acrylic. I have two tanks with acrylic "windows" that are leakers. The first is a 360gal with 1/2", the second is a 630gal with 1". <Mmm, I'd likely try resealing them...> I have been talking to people about this for months and I think the problem is the sealant. Silicone doesn't bond to acrylic very well. Options that I have come up with are drilling the acrylic and frame every 4-6" and bolting it in place, or looking for a better sealant. The better sealant I have found is Sikaflex. It is used on boats to seal windows at depths up to 10'. My original plan was the bolting but the acrylic shop recommended against it as it could stress the acrylic on the holes. What do you suggest? <Hmm, how tall are these tanks? I would likely drill and screw the acrylic, coating over the hardware in the tank with two-part water-proof epoxy, cut away the existing 100% silicone, let it dry for a day or two... wipe the surface down with an organic solvent (we used to use toluene, xylene...) in a well-ventilated setting... and then re-apply a nice, thick bead of silicone... maybe "feathering it out" with a plastic trowel (small ones available at Home Depot, Lowe's...). IF the tanks are only a couple (as in two) feet tall or so... Otherwise, I'm a bit nervous given the width of the wood and acrylic sheets myself. BTW, do look into used glass... especially "old glass doors" for your "humungo tanks"... sometimes these are available from companies that take down old buildings... for very little money> For sealing the wood I have been using 2 part epoxy floor paint. I have been looking at using fiberglass. What are your thoughts on this? Epoxy or Polyester resin? Should I cover the tank with fiberglass mats or just pour the resin and hardener on? <I have made many (hundreds) of tanks for science and industrial purposes using fiberglass cloth stripping (you can buy it as such... I would), and polyester resins... mix the hardener (likely MEK based) with the resin/s as instructions call for (do allow for temperature, time...) and lots of air circulation (have had the worlds worst "highs"/headaches from breathing in too much, too long... One coat, wetting the inside corners first, then apply cloth... wear clothes you really don't like, intend to keep... gloves... Have someone there to help "hand" you things...> I'm also planning a large tank of about 16' long, 4' deep (with 30" window), and 6' wide. Should I go to cement for something this large? Thanks, John

Re: tank building questions Thanks for the fast reply. The current tanks are 2' deep (360gal) and 3' deep (630gal). I like the idea of using the screws/bolts. <Do apply another 3/4 sheet to the front/face of the 3' deep tank for strength/rigidity... I would drill pilot holes every six inches use 2 or if you can find them 2 1/4" brass screws, counter-sink the heads in the acrylic...> What size would I need and how often do I need to bolt (i.e. every 4"?) I think the acrylic is thick enough. There is no bowing. The acrylic over hangs onto the tank by about 5" either side. Again, Thank you for the help. John <Perhaps you should consider a career in the public aquarium exhibit design, fabrication business? Please take a look at the book reviewed here: http://www.wetwebmedia.com/afascfishpowell.htm Know you would enjoy, gain by reading it. Bob Fenner>

Suitable Epoxy Paint for Plywood Aquariums Bob, <Anthony Calfo in your service while Bob travels> I've been looking over your fine website and have not yet been able to pin down any brand names for epoxy (or otherwise) paint to seal plywood tanks. I've made inquiries to various paint dealers here in Kansas City and they're all very gun-shy about selling epoxy paint for an aquarium--Sherwin-Williams wants me to have a meeting with the tech rep before they'll sell it to me! Thanks for any assistance! Mark Lynn <Mark... for smaller aquaria under 200 gallons, tub&tile epoxy (advertised as Baby safe once cured) is commonly used in aquaria. Available from your local DIY store, it is convenient if not inexpensive. For a larger project, I would take the paint rep up on the offer to protect your investment. You'll want to avoid paints with anti-fouling agents in them (for mold and mildew...very toxic to aquatics). Best regards, Anthony> Suitable Epoxy Paint for Plywood Aquariums II Thanks--the tanks I'm working with are around 100 gallons. Is this a paint used for repairs to tubs, etc? MRL <exactly, my friend. For cement laundry/wash tubs and the like. You may be a little restricted by popular home decor colors (grey, tan, white, black) but as long as it says Baby safe when cured as most do, you will be fine. Even if it doesn't you are likely safe if you are willing to test. Worst case scenario is you have to give another good coat over it. Best regards, Anthony> Suitable Epoxy Paint for Plywood Aquariums III Thanks, Anthony--I'll check out Lowe's and Home Depot tomorrow. I've also considered lining them with countertop laminate ($2.00/sq ft) and sealing the joints with silicon. I'll do some price comparison and go from there. Thanks again, Mark <For what it is worth... I have used Olympic brand swimming pool paint in concrete ponds and know that they at least have a product that is fish safe. I'm just not sure if it adheres to wood as well. It was designed for concrete applications specifically.>

Suitable Epoxy Paint for Plywood Aquariums IV I tried some UGL --formulated for concrete-- it seemed to work fine for several months, then I got a small leak. It looks like the paint cracked along some grain lines and the plywood got soaked. I let it dry for a couple of weeks, the gave it another couple of coats. Worked fine for a couple of weeks--until I added the rock--I think the extra weight of the rock caused the wood to flex just enough to make the paint crack again. MRL <Ahhh.. yes, thank you. I'll remember that for the next query on the subject. We'll stick to ponds with it <wink>.>

I used the wrong Silicone sealant Hi Bob, I was just reading the articles on "One hundred percent Silicone... no mildewcides, other additives" under Building your own tanks, enclosed is a picture of the tank setup I made using 3/4 marine ply oak faced, then fiber glassed, epoxy painted and then I used silicone for Bath and Kitchen. <To just place the viewing panel?> It of coarse made me sick when I read the thread on mildewcides. My question is the equipment, base rock and live rock which was in this tank , I have the rock in a new tub with fresh saltwater "hoping" and the equipment has been clean completely What is your feeling on any of these items being reused in another tank ?? Thanks Tony <Mmm, should be fine. But I encourage you to cut away the exposed sealant and silicone over the old with 100% if/when you have all out of this aquarium. Bob Fenner>

Re: I used the wrong Silicone sealant Hi Bob, Yes the viewing area as well as a skim coat over the rest <Really? Over the rest? I/we've made a bunch of wood, fiberglass and resin tanks over the years... if a couple of feet or less in height we only applied strip (can be bought as such, thank goodness) cloth and applied in corners... applying resin (and hardener natch) over all...)> :( I'm thinking of lining the rest with glass which is the way I should of gone in the first place . It certainly wasn't a cheaper way to go doing it the way I did "Could of bought two 180gals by now" heehee But live and learn. Thanks for the info awesome site by the way, I wish I'd of know of it before my giant screw up. The size of the tank is 30"HX30"WX96"L forgot to include that last email. Again Much Thanks Tony <Thanks for the follow-up... Silicone is almost impossible to get anything to "paint over", stick to it... Your suggestion might be the best... alternatively you might save some money using very thin acrylic sheet in its place. Good luck, life. Bob Fenner>

Custom Aquarium Bob, I am building myself a custom aquarium. It will be 100"Lx 48"H x 42". The back, bottom, and sides will be made of pre-laminated 1" plywood. All the seams will be reinforced on the outside with Steel Angles. The front, viewing area, will be a sheet of 1" prelaminated plywood with a window 92"L x 44"H and a 96"x48" sheet of glass "siliconed" to the inside of the "window". Finally there will be 3 evenly spaced 3" cross ties tying the front of the tank to the back. I am struggling with determining the thickness of the glass. Is 1/2 sufficient or should I go with the 3/4? Any insight you can give would be greatly appreciated. <I would spend the extra money on the thicker glass... Look into some of the fancy laminated brands (Starbrite for instance)... as these may be fine at 1/2", though not cheaper than 3/4" cast... Bob Fenner> Please respond to my home email address. Thanks, Mike

Re: Glass Weight Steven, Good link RE glass thickness, tank building etc. <You are welcome.> What is your opinion on building plywood - glass tanks? It just seems too easy and cheap to be true. If I thought I could make it from plywood in this manner, I would construct something in the order of 6x3x30"....... do you think they are a good idea? Cheers, Matt <Good luck! Please report back with your results. -Steven Pro>

DIY Glass Tank Hi Steven, Thanks for the reply Re the maculosus angel. <You are quite welcome!> Quick question..... do you know a site where to read up on DIY all glass tanks etc, design including how to calculate the weight of glass required etc..... Cheers, Matt <Have a nice weekend! -Steven Pro>

Plywood Tanks What is the best way to clean algae off of plywood epoxy sealed tanks and also acrylic fronts without scratching it? <There are special acrylic safe cleaning supplies available from any fish store. The wood is another matter. I doubt anything in reason would scratch it. I would not use metal razor blades for sure, but any standard aquarium scrubbing material should be ok. -Steven Pro>

Plywood tank Hi guys.. <A.J.> Thanks for putting your time and resources into the best aquatic information website ever...So many of my questions have been answered (some I didn't even know I had) by happily perusing the posts on your web site. I do have a question I could not find answered anywhere though... <Okay> I am planning on building a large plywood tank and do have some experience building them, as well as glass and acrylic tanks/sumps etc. I think I have looked at every plan available that I could and that find that many of them are structurally sound and tested methods. The main problem I see with building these tanks is of course sealing the non glass portion of these tanks. There are many methods the best I've used being several layers of epoxy or fiberglass resin, all of these work for sealing the wood but are very labor intensive. <I've used a few methods with plywood constructed tanks... like wood-glue or such jointing of corners along with good metal screws, then pre-made rolls (usually four inches wide) resined into the inside joints...> I had an idea, as yet untested that I thought I'd run by you. Basically it consists of structuring the plywood box with a glass front, but instead of sealing the inside with epoxy, line it with a 1/8 inch layer of acrylic or pvc. structurally this thin layer would do nothing. It is only to seal the wood. this would have the advantage of being easily drilled for overflow/bulkhead fittings. The obvious problem I see is what to do the actual sealing of the front glass to the acrylic sides and bottom. I don't think silicone will do the trick. Do you know of any kind of sealant product that will adhere to both glass and acrylic well enough to be used in this type of application? <I don't... though if you use PVC sheet instead (cheaper, and just as strong, serviceable for what you have in mind here), there are reasonable "welding" options for making the "shell" within the plywood/structural box as you describe... BTW there have been a few companies that fabricated tanks in a similar fashion (Aqua Decor and their mainly "bubble" tanks, our old company's Nature Etc, Inc. spun polyethylene tanks within furniture stands... They can/do work> Please tell me if you think this is impossible so I can get it out of my head, Thanks. A.J. Ginther <Look into the PVC sheeting possibility... a few folks use this material as a stand alone structural component (Quality Marine in Los Angeles most innovatively). Bob Fenner>

Re: Plywood tank Thanks for the reply.. <Welcome> Am I understanding this correctly? Are you suggesting I do the whole inside with pvc including the front piece, or are you saying I can adhere a front glass panel to the inner pvc panels somehow? <The latter. The glass/viewing panel (acrylic if you want) can be nestled into a bead of silicone, against the PVC sheet, with the PVC sheet in turn being supported (all but the cut-out for the glass) by the structural frame> I looked at clear pvc panels for the front and they are a little pricey for my needs. I already have the glass. <Look at the opaque sheets... you don't need the clear... and shop around (maybe online) for larger distributors. They're much cheaper. Bob Fenner> Thanks again
A.J. Ginther

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