Why not plywood?

[igoRluse]

I'm hoping to join the big tank club once I've gained some experience and I already have the fish room included in my new house that should be ready to move in soon enough. I've been reading around alot and am a bit puzzled as to why all the tanks pics I have seen so far are all glass or all acrylic tanks. In-wall tanks typically being visible for only one side, plywood seems to me like an obvious solution. Add onto that the $5000+ price for a nice 120 * 36 * 36 RR acrylic and I'm even more puzzled.

What's the deal? Are there any reasons why you wouldn't want to build a large tank in plywood?

[tomasz]

Plywood? What do you mean?

[Slicktrax]

I know why I didn't, lack of skills on my part. Check out the DIY section, there are quite a few threads on building plywood tanks. It looks like a great way to get a large tank at affordable prices.

[Nagel]

300g acrylic, brand new, but bought second hand (still had the acrylic peel coat on it, never used). $500 That's why I didn't chance building a plywood tank.

There is a TON of info in the DIY section on plywood as well as concrete tanks. It's just a level of comfort for some to just purchase a tank. Those with the skills, tools and know-how do build some killer plywood tanks....

I'll probably build an outdoor frag tray next summer, something like 10-12ft long, 4 ft wide and 12 inches deep, but I will use a rubber pond liner and there will be no viewing window. Still, probably be assembled with plyywood and 2x12's.

[igoRluse]

Cool, I was under the impression nobody was having a go at large plywood tanks because of some drawback. If it's feasible, I'm definitely going to put in my plans.

Cheers.

[picassomike]

http://www.cichlid-forum.com/articles/diy_1700g_tank_1.php

Check out this link,gives you lots of info on building a large plywood tank.

Mike

[mps9506]

One drawback with a very large plywood tank is that you don't have any visability through the back where you might be doing lots of tank maintence. When moving frags or corals around it is always nice to be able to see what you are doing through the glass or acrylic.
That's the only reason I could think of.
Mike

[Mastino Mike]

For people like myself who cant afford a large acrylic or glass tank, plwood is the only way to go. Leaks are the only concern, a major concern. My only advice wood be think seriously about using a pond liner instead of epoxy paint. It has worked for me and dont understand why more people dont use pond liners. Building a large tank is easier than you think. Also plywood tanks are only cost effective if they are over 200 gallons.

[ChrisB]

Mastino Mike - Can you tell me how you sealed the liner where it meets the glass? In other words, is the liner between the glass and wood or on the innermost surface of the glass. Sealed with aquarium silicone? Wonder if UV from the lights will degrade it?

and where did you get it? Is it butyl rubber?

Thanks

[nancysnuwave]

Originally posted by Nagel
I'll probably build an outdoor frag tray next summer, something like 10-12ft long, 4 ft wide and 12 inches deep,

I'm curious to know more about your idea for an outdoor frag tray.. do you control temperatures? what about rain/wind?

I assume you are wishing to increase your productive area w/out increasing your lighting costs?

Chris

[Mastino Mike]

The rubber pond liner is uv resistant. I used acrylic but glass is much easier to install. I used edpm rubber from justliners.com but butyl rubber would work also and I believe you can get it preshaped to fit your tanks specs. The liner is the innermost layer. Silicone is all you need for glass. I used weldon and then silicone for acrylic.

[griss]

Here is a thread about a local (St. Louis) plywood tank that is viewable from three sides. Pretty cool.

One local reefer here built the tank and sold it to a friend of mine.

George

[igoRluse]

Originally posted by griss
Here is a thread about a local (St. Louis) plywood tank that is viewable from three sides. Pretty cool.

One local reefer here built the tank and sold it to a friend of mine.

George


Hmmm, link?

[griss]

Originally posted by igoRluse
Hmmm, link?
Sorry posted that while at work and rushing off to a meeting:D Here's the link http://archive.reefcentral.com/forums/showthread.php?s=&threadid=280450

George

[Forestal]

I'm also planning a very large plywood/glass tank. I already have a 120 gallon, that cost 100$ to build. building a bigger tank will really just be more complicated for plumbing etc.

[FuzzyDean]

I can understand wanting a bigger tank and making one out of plywood and using the liner is a great idea. When I read people talking about it being cost prohibitive, I often wonder about the coral and how can you provide a good environment for them. I mean, skimmers, filters, refugiums, pumps and lighting cost allot to. So how can you justify going cheap on a tank when that is really one of the smaller costs in this whole hobby. And also, why would anyone want a hugh tank if it cost so much when you have to think about "What if it crashes". Just curious and I may build one myself. Not for size, but to fit where I want it to go.

[Mastino Mike]

Building a large plywood tank can save you thousands. If you are building a large reef tank, it will be expensive no matter how you cut it. If you are starting a fish only or fowlr its extremely cost effective.

[Mastino Mike]

I am still under 3 thousand for my entire set up.

[igoRluse]

So how can you justify going cheap on a tank when that is really one of the smaller costs in this whole hobby

Tenecor 96 x 48 x 36 : $4714
Tenecor 96 x 48 x 48 : $7974
Tenecor 96 x 48 x 60 : $9509

Or while we're up there in those prices, might as well go for the best

Tenecor 120 x 48 x 60 : $13118

95+% of these tanks will be in-wall types only visible from one side. They could all be built from plywood for a fraction of the cost.

Enough said.

[jamielind]

i was wondering. why not use thinner acrylic instead of paint. as long as the plywood is keeping the acrylic from bowing you could use as thin as 1/8 inch which is alot cheaper than thicker acrylic. am i missing something or does this make any sense?

[igoRluse]

Originally posted by jamielind
i was wondering. why not use thinner acrylic instead of paint.

Well I am wondering why use thinner acrylic instead of paint?

Your idea would be to use acrylic just for waterproofing but IMO there are more simple ways. If the plywood is well build, epoxy paint works just fine. If you're afraid, fibreglass tape around the seams of the plywood and epoxy paint over it all is a proven solution.

[1234]

I have built several smaller plywood tanks 125gal and 250gal. I just used fiberglass cloth in the corners and then just mixed the epoxy and just poured it in till I got a 1/8 - 1/4" thickness all around. And then just silicone the glass into place. No leaks, and very cost effective.

Our next tank will be in the 330 gal range

Checkout david gregor's site, he has a good size in-wall plywood tank

[jjmg]

Anyone have any pics of their tanks? The pond liner idea sounds good since from what I've read one of the big problems is the fumes from the epoxy.

[MarkS]

Originally posted by jjmg
Anyone have any pics of their tanks? The pond liner idea sounds good since from what I've read one of the big problems is the fumes from the epoxy.

The fumes dissapate very quickly. Personally, I'd never use a liner, either acrylic or EPDM. The last thing you want is for water to get between the liner and the wood. Epoxy with fiberglass tape on the seams is strong and water tight. The people who have had trouble with the epoxy method either did not use enough epoxy, did not seal the joints first (LiquidNails works great for this), did not use enough fasteners or the wrong type of fasteners in the joints or used inadequate bracing.

The liner method is cheaper, but all it would take is a small tear and you have wood rot, even after fixing the leak.

[mps9506]

I don't think pond liner is a good long term solution either. It's pretty common for pond liner to be replaced on outdoor ponds every several years do to uv wear. I dunno how much UV we get in the reef tanks compared to outside, but I'd rather not have to break down a tank to replace the liner.
Mike

[jjmg]

Does anyone about how long the epoxy will hold up under the UV? I'm sure this epoxy is used for inside holding tanks so I'm thinking it is pretty tough stuff.

[1234]

If you think about it, the inside will be covered in coraline algae within 6 months or so, and the sides will be coverd in it. Or something is wrong.
The epoxy acts as a "liner" with the fiberglass cloth (woven) reinforcing all the corners. You do have to work outside when you are using the epoxy - or you will get kind of light headed. :eek1:
I would use glass for the front - eaiser to scrape clean and less $ than acrylic and eaiser to attach to the tank with silicone.

JMO

[javatech]

i made a small one 140 gal and i used the 2-part epoxy paint and a pond liner just to keep things from the paint
http://groups.msn.com/JimsCichlids/plywoodtankphotos.msnw

[Mastino Mike]

Does anyone have a tank made with epoxy that has been up for more than 8 years with no leaks. I have a friend that has a 850g plywood tank made with glass and a rubber pond liner it now houses a huge green moray. Its been up 8 years now. I have never built an epoxy coated tank but have seen enough problems with them to know better. I like the liner for its simplicity and cost.

[jjmg]

Mike, that dog is just butt ugly! It's got to be a chick magnet! how long has your tank been up? How did you join the liner and the acrylic? I tend to thing of tanks lasting forever, but I just took down a 29 gal freshwater that had been up for about 15 years and was surprised to see the bubbles in the silicone that didn't show when it was filled.

How long can you expect a plywood tank to last?

[Mastino Mike]

Thats my dogs uncle. Here is a pic of my guy. Dante dello Stradone imported from italy. I guess you do have a point jjmg, I dont know how long my tank is going to last. Its just a fowlr more like a FO with a little live rock. If the tank lasts me more than 8 years without any problems I will be happy. I could build two of these tanks and still come out cheaper than a all glass or acrylic tank. Hopefully I will be moving into a larger home by then. I plan to keep this tank lightly stocked so all my fish have plenty of swimming room and just hope for the best. You can have a leak with any custom build or any tank. The liner to me is very durable and you can get them in 65mil thickness. I like liners better but when dealing with large volumes of water we have to do what we are more at ease with.

[1234]

My last tank the 250 had been up and runnig for 4 yrs. My buddy has it now but it's dry for about 3yrs now.

If you use quality materials, use water proof glue and stainless fastners, you should have no problems.

That 250 was build using 3/4" oak/faced plywood, a water proof glue, framed in front with oak pieces, with plain drywall screws. every 6", some guys use a spacing of 3" or even 1.5" but that's over kill. With a thick enough layer of epoxy, 1/4" reinforced with fiberglass cloth at all corners, not mat, it'll last a long time. If you keep the tank dimensions with in reason, you won't get any bowing. But again, it all depends on the prep work and assembling of the tank - quality of workmanship.

It sounds like you want to use the liner - go for it. Your choice.

:D

[Mastino Mike]

Its sounds like your tank was made correctly. The liner is much easier to install no smell, now worry about coating corners and also its flexible so if you have bow in the plywood its more forgiving. I guess it does come down to quality of workmanship but how about ease of install?

[SaltwaterNovice]

Anyone have a link to plans for these plywood tanks?

Thanks,

Brian

[Forestal]

Brian, check out http://www.garf.org for plans to make different types of tanks and stands.

also, here is my input after trying their plans out:
http://www.cichlid-forum.com/articles/diy_plywood_aquarium2.php

Picture of my 120:

http://reefcentral.com/gallery/data/500/41973tank3.jpg

[SaltwaterNovice]

Dan:

Very nice Frontosas, tank and write up.

Thanks,

Brian

[Forestal]

thanks

[jjmg]

Mastino Mike, that dog is wonderful! Looks to be at least 1000 years old.

What problems have you heard of with the epoxy tanks??? Is it from the flex in the plywood? What if you braced the plywood so flex would be minimal?

Do you have any pics???

[Mastino Mike]

Im sure if built correctly and the corners are coated properly and the viewing window is siliconed and sanded properly you wont have any problems. I think bow or flex plays a part but the ones ive been around always leaked eventually. I worked at a pet store and we had several. The small leaks would come from the corners or the front viewing window some after a year or two.
I can tell you why pondliners are better.
Alot cheaper
No smell no fumes no mess you can build inside at the location you want to set it up at. Try moving a 500g or700g through a doorway.lol
The liner is more forgiving, more room for error. If the plywood bows it doesnt matter as much the liner is flexible.
Easier to install, You can have the tank filled with water in 3 to 4 days tops just waiting on the silicone and glue to dry around the front window.
Why paint on rubber epoxy when you can get a preshaped liner to fit your tank specs and slide it right in, or a flat sheet of edpm?

Durablility is up for debate, The liner could be punctured with something extremely sharp. The epoxy could get a deep scratch?
These are all just my opinions, the liner has worked for me and other people I know with no problems. Epoxy may work the same but you have to do what you think is best.

[Mastino Mike]

Pic 1

[Mastino Mike]

Another

[nancysnuwave]

Originally posted by Mastino Mike
the liner has worked for me and other people I know with no problems. Epoxy may work the same but you have to do what you think is best.

[looks like you posted pictures, same time I wrote this note! ...up early this am?]

Are there seams w/ the pre-fitted liners?

BTW. .on your 700? do you have viewing from two sides?

One more inane question..do you cut the glass area out yourself, or order the liner w/ that part already removed?

It would just seem that diy makes the whole issues of cutting your own holes for bulkheads that much simpler. BTW. any tricks on doing that (drilling through liner so as not to cause rips or stresses In your pictures, your seem to bring all of your spray bars, etc, from the top.

Chris

[Mastino Mike]

Another

[Mastino Mike]

Last
The tank consists of 6 fish so far.
Hippo
Mimic(black and white) or chocolate tang
Yellow
RS Sailfin
Yellow eye kole
Emperor Angel.

[Mastino Mike]

I have the return from my 100g sump coming over the top of the tank because of syphoning. I also placed all the bulkheads high and just extended the returns or intakes. My plumbing is unsightly but I was worried about placing the bulkheads low and water pressure causing leaks or salt creep. The tank is 4 feet tall. If I ever have to work on the bulkheads I wont have to drain the entire tank. I drilled my bulkhead holes before I placed my liner. Then come back with a very sharp razor or pair of scissors and cut the holes through the liner( you will see how puncture resistant the liner really is) I Think that butyl makes the only flexible box cut liner if you are worried about wrinkles or folds. I used a flat sheet of edpm. You cut a window out of the liner to match the front frame or plywood cut out. The liner is the inner most layer. Tank, glass or acrylic, then liner. The water pressure holds the liner in place and helps to form a water tight seal.

[SaltwaterNovice]

Mike:

How did you construct that tank?

Did you make a frame and/or use supports?

Any construction pictures?

Thanks,

Brian

[Mastino Mike]

Brian, I used a 4x4 frame around the base of the tank and around the top. It does not have any cross braces on top. I also used 2x4s to brace the acrylic window. I used pressure treated 4x4s but it doesnt come in any contact with the water but next build I wont use them. The 4x4s are connected with liquid nails and 8 inch timberlock screws from home depot. So you want more pics? No problem

[Mastino Mike]

Tank is sitting on its back and the front window portion is facing the ceiling.

[Mastino Mike]

The 4x4 frame also gives you something to tack the liner down to.

[Mastino Mike]

Last

[Forestal]

Mike,

the liner looks like a great idea. im wondering, did you place the liner under the glass with silicone? ive heard liner and silicone don't stick great. im curious how to get the glass/liner joint as a good seal

[Mastino Mike]

The acrylic or glass is not inside of the liner or on top of it. The liner cut out matches the front frame of the tank. The glass or acrylic is between the front frame and the liner. If installed correctly their is no tension on the liner/glass or acrylic attachment at all that is the beauty of it. Water pressure pushes and holds the front liner cut out up against the inside rim of the glass and helps to form a water tight seal. If you are using glass silicone will be all you need. I used acrylic, I sanded the inside rim of the acrylic sheet then used weldon 16. I also used super glue when the weldon ran out. I let that dry for two days then I siliconed over the entire attatchment and let that dry for another two. My suggestion would be to order some samples of different types of liners and do some tests like I did to see what you think works best. My attachment has no tension or stress on it at all. If using a flat sheet of edpm rubber make sure your corners have enough slack so when the tank is filled it doesnt pull on the attachment. You want the water to work for you not against.

[Soltaker]

Thanks for all of the great info Mastino Mike. I am going to be buying a house this spring, and I am dreading moving my 220. Being that the use of plywood and a pond liner seems so cost effective, it looks to me like it is my beast choice. I can't forsee having a problem building a 300 gallon + tank for a fraction of what an acryllic tank would cost. So please bear with me if in the coming months you get a few PMs from me. :)

BTW......beautiful tank you have. :)

[Mastino Mike]

Not a problem. I will be more than happy to help the best I can. I will be doing another large tank hopefully very soon at a friends so Ill post my progress step buy step.

[Soltaker]

awesome :)

[shadofax69]

I was just wondering if you can use MDF instead of plywood. As long as you coat it well with epoxy is it stong enough to hold the weight of the water or not.

[Forestal]

I have never read anyone using mdf, and i woud be a little concerned using it. but let's see what some experts say :D

[Forestal]

also, i am planning on making a big tank in the future, just planning now. let me know what you think. plan for plywood/glass with inner cube 2x 2 feet for viewing 360 degrees. I am planning what i will need for plumbing/lighting/skimming/calcium etc. this is a project to plan and plan, then take slow.
plans not the best, no cad software :)

http://reefcentral.com/gallery/data/500/41973tankplans.jpg

[toonces]

forestal-
what a cool idea. i hope you go with it.

how would you access the center cube though?

[Forestal]

try to picture the tank sitting on a large stand, open a door and crawl underneath to the cave. hehe
i can't wait to get to work on this.
my only thing other than a specific parts list is to see if i can manufacture my own skimmer, and figure what i will have to deal with for evaporation, coming up with an efficient system to have ro/di water available.

i have never done a big tank (120 is biggest and is FW) so i am avidly reading in this forum:D

once i actually start anything, i will document

[cryosphere]

I built an approx 270g plywood tank on a whim and it turned out well.

The most expensive part of it was the epoxy I lined it with. I tried the pond liner but I could never get it smoothed out enough for my liking. So I epoxied the inside with several layers that I tinted blue. Good part was that it never leaked. Bad part was that I had just finished leak testing and I made a job related move and I have no room in my new place for it!

[ChrisB]

cryosphere - This is kinda OT but I was reading your current tanks and saw you have a 40QT and a 10 HT. I am thinking of going with two QT type tanks, 1 for LR,invertebrates,etc. and 1 for fish only with only pvc.

I was just wondering what the difference was in your case.
Thanks
btw I am working on finishing my own plywood tank. Weather is putting off the epoxy painting until spring. :(

[cryosphere]

Hey Chris,

My 40g has a DIY concrete background so I didn't want to add any meds to it for fear that the concrete would soak some in and I wouldn't be able to get them out i.e. copper. The 10g is bare.

Not sure what your setup is like at home but I epoxied my tank in late fall/early winter in my garage. I had to use heaters to get the epoxy to set. Wife wasn't too impressed cuz I left our vehicle out in the cold!!

I kinda enjoyed doing the plywood tank and I'm very interested to see how Forestal's idea turns out. I daydreamed of a similar design and would love to see one built.

Forestal - lots of pics please!!

[Forestal]

Don't worry I will. but i'm not allowed to start until i finish a few other projects first.
after i finish the basement off, i told her i will start cutting and glueing.
even though it looks elaborate, it won't be much to put together. it will be a pain to epoxy, and then the plumbing will be more complicated.
i really can't wait till i start on this.
and thanks for the encouragement.
my wife thinks i'm nuts, :)

[cryosphere]

Forestal - I was just curious as to what your plans were as far as attaching the inside viewing area to the main tank. What are you going with for the viewing area...combo plywood/acrylic, straight acrylic or glass? Have you made it to that point in the planning stage yet?

Not that I'm trying to pressure you into getting the thing started or anything!!

[Forestal]

hehe,
actually i have plans all drawn up, cut lists, etc.
the inner viewing area will be like the rest of the tank, plywood with glass window all sides, whereas the outer portion of the tank will only have windows in two sides.
I like this because there will be some areas only possible to see from inside the tank.
basically this will be like making four tanks, but removing 1 wall from each.
the walls of the inner area , just like the outer will be glued/screwed to the bottom piece,and to the braces on top.

the more i talk about this, the more i want to get started.

since i am a saltwater newbie, i will be probably hosting a dsb and some fish for a while, while i deal with evaporation, calcium issues. big tanks are completely new.

[cryosphere]

Originally posted by Forestal
.....the more i talk about this, the more i want to get started.

hehe, I knew I'd get ya!!

Sounds great. When I was dreamin about a tank like yours, i thought of a big acrylic dome. Not sure where you could get one though but I've saw one at a zoo where kids could stick their head up into an otter exhibit.

I also thought of screwing some 2x2s side by side on the bottom of the tank and with enough space to create a slot that you could snug fit the acrylic/glass into. That way you could eliminate most of the framework for a larger viewing area. The viewing area shouldn't have a problem with bowing because of it's size...okay, now you got me thinking!!

[Earl87gta]

What do you guys think of using the spray in bed liners after you build the plywood tank that stuff is inditructable The guys around here are using it in there shrimp boats so it cant be to toxic if they are keeping the shrimp in the boat after being spraid with the stuff.

[javatech]

maybe if you coat it with some of the two part epoxy paint. they don't keep the shrimp in there that long plus im sure they pump fresh sea water in there all the time

[mps9506]

I would still go with the epoxy, because while they may coat the boat with bed liner, they make the boat from the epoxy.
The reason they use the bed liner is to prevent craking and physical damage to the fiberglass parts or if they use playwood, to the wood stringers etc. on the boat.

Mike

[Forestal]

Just an update, decided to go with a more conventional design, so less chance i will screw it up :D

here's a link to its own post, slow going so far, as I'm working a lot of hours. :)
http://archive.reefcentral.com/forums/showthread.php?s=&threadid=308681

[ONAGI]

I read on some other tanks done like this were they line it with thin acrylic or plexiglass to prevent any scratching.