# Plywood Tank 250gallon



## Coln

Hi started this tank a few weeks ago to make this existing tank bigger but have been
reading TFG, 13lazd and 98dak83cam for a while which kinda made my mind up to
go for this tank.
I'm making a 250gallon plywood tank which will be in the garage but viewed from the 
lounge. I'm posting it on a uk forum as well hope thats cool, share everything yeah















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## auratum

Cool! How will you be sealing the plywood?

Good luck with your build!


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## Coln

auratum said:


> Cool! How will you be sealing the plywood?
> 
> Good luck with your build!


 West system 105 Marine epoxy


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## auratum

Cobain said:


> auratum said:
> 
> 
> 
> Cool! How will you be sealing the plywood?
> 
> Good luck with your build!
> 
> 
> 
> West system 105 Marine epoxy
Click to expand...

Did you buy it yet? You may want to check out Progressive Epoxies. The web site is a bit confusing, but I think you get as good as or better product for a lot less money. This is what I will be using.

http://www.epoxyproducts.com/


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## I3lazd

Also look at U.S. composites epoxy it was very well priced and works very good. I see you bolted the corners together but it looks like that is it. Are you planning on going back and lag bolting into each of the boards or are they already it is hard to tell in the picture? not sure but if not Just those screws will not hold all that pressure. I would also recommend putting braces on the top and bottom of each board. Can't be too safe. other than that is it lookin' good :thumb: . Good luck man it is an awesome project and well worth the time.


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## Coln

Already got the epoxy, am using 12mm/ 1/2" threaded rod to bolt all the panels together about
12" centres with 'lock' nuts


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## I3lazd

threaded rod is a pain in the a** to use. I tryed that originally then switched over to the lag bolts. Here is what I used to bolt down my tank, you just need to pre-drill as to not split the wood.








These are much easier to work with.


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## Coln

Think I need the strength of the 12mm bolts and cause the tank will be on two concrete block
walls I can get below to tighten the nuts. Plywood is 18mm and framing is 100mm x 50mm and
glued and screwed and is really solid


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## I3lazd

Those will works great I was just tryin to save you some time and hassel.


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## Coln

Frame enlarged, mate just built a house and had excess yellow pine cheers Neil :thumb:


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## Coln

Finished the epoxy well impressed with west epoxy really pleased with finish


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## I3lazd

are you going to just silicone the seams together or go back and fiberglass them together?


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## Coln

Going to silicon it all together, the silicon will just be a seal cos the bolts will hold the tank
together plus if it does have to come apart for any reason would be a bit easier


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## I3lazd

ya that is how i plan on doing my next one exactly how you are doing it it is way more effective. :thumb:


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## auratum

Looking good!

Did you use fiberglass cloth with the resin? If so, what weight cloth did you use? Did you do mulitple layers?

Thanks!
Patrick


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## Coln

That's the first time I've used epoxy and would use west again the stuff is easy to use unless all epoxy is the same but I doubt it.
Colouring the last coats is the way to see what you've coated


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## I3lazd

did you fiberglass it as well or just epoxy?


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## Coln

Yes, the base I used thick fibreglass from a mate that was for roofs so took a lot of epoxy but
with the weight of rocks will need to be super strong.
The walls have a thin layer but always better to have fibreglass in the epoxy makes it 
a lot stronger


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## Coln

Assembled tank today everything fitted well when bolted up, screwed rod was good for various lengths and easy to cut in the vice. Gonna coat front panel again as screw holes look coated
but are not final coat black.  On holiday for a week now so hope to get blocks built and last coat of epoxy and start planning for change over....


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## Coln

Blocks finished today, hope to move existing tank down next weekend and take old blocks down
to new level then start assembling tank


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## auratum

Cobain said:


>


Cobain - this looks really nice, but I have a concern about the back corners with respect to strength. The concern is due to the way that the side is connected to the back. I could be wrong, but from the pictures it looks like all the strength in the back corner is coming from the shear strength of the plywood. It would have been better to extend the framing of the side wall all the way to the back corner and then tied that into the back wall. From the picture, it looks like the side piece bolted to the back wall through the plywood is not connected to the rest of the framing for the side wall - that is the apparent weak point. If you replace that piece with two 2x4â€™s or a 4x4 and bolt or screw it to both the side and the back then it will increase the strength significantly for these back corners.

The way it appears to be built from the picture could allow outward pressure on the side wall to shear the plywood at the back wall â€" causing a failure at the back corner. You have the added benefit of the fiberglass strength, but if it were me, I would change how you tied the back corners together.

Good luck with your build - it is coming along nicely!
Patrick


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## scottiefish

i agree with auratum. it looks super, but the corner may be an issue. go with the 4 by 4 in the corners and bolt it to the sides and the back. cant wait to see more! :thumb:


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## I3lazd

I agree he shouldn't have cut the 2x4 off at the end, he should have left them so he could bolt a 4x4 into the bottom and bolt in from both sides of his support beams.


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## Coln

Thanks for input guys, the plywood is fixed with flooring screws and glued to all the 4x2 and the end piece of 4x2is screwed thru the plywood and thru the end post of the side panel.
It's totally solid as the 3 bolts that hold panels together each corner are used to hold big roof trusses together. I also plan to put metal supports on top of the panels at corners and further in to start anyway, pics of screws and glue :thumb:


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## I3lazd

If you mad that minor adjustment it would mean a world of diff. in support and be an easy and cheap fix. Just my 2 cents though.


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## Morpheus

I think it will be fine. The key is he said he screwed and glued the the 2 x 4 on the end frame into the cut down 2 x 4. For the tank to fail, it's going to have to have enough pressure on the back to pull those screws out, bend the screws that go through the plywood into the back frame, bend the screws in the cut down 2 x 4, break all the glue free, and bend some seriously big (3/4"?) thick bolts. Not to mention the fiber glass on the inside of the tank.


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## Mcdaphnia

I3lazd said:


> If you mad that minor adjustment it would mean a world of diff. in support and be an easy and cheap fix. Just my 2 cents though.


 I for one cent worth don't agree. At least not in the direction an adjustment might take. This tank is not so tall that it really needs any of the 2 by 4 ribbing at all. I've built 42" tall tanks over 500 gallons with out any ribbing, just plywood screwed together and never had any leaking or bowing problems. It looks solid as is, though if the ribbing had continued out to the ends of the walls, it would have looked tighter. A nylon strapping band just in front of the seam over and under the tank would do more than a 4 by 4 to keep the plywood from deflecting, which it probably would not at this water pressure. A 4 by 4 however introduces complications, from whether or not is is safe for interior use, to the tendency of 4 by lumber to twist and bow, taking the plywood with it.


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## I3lazd

updates???


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## Coln

Have built second block wall and taken original down to new level.
Planning to assemble tank in position on friday and fill on sunday.
That will be the moment of truth, will post on sunday pm my time.
Pic of the left side background in progress
How's your tank going?


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## auratum

Mcdaphnia said:


> I3lazd said:
> 
> 
> 
> If you made that minor adjustment it would mean a world of diff. in support and be an easy and cheap fix. Just my 2 cents though.
> 
> 
> 
> I for one cent worth don't agree. At least not in the direction an adjustment might take. This tank is not so tall that it really needs any of the 2 by 4 ribbing at all. I've built 42" tall tanks over 500 gallons with out any ribbing, just plywood screwed together and never had any leaking or bowing problems. It looks solid as is, though if the ribbing had continued out to the ends of the walls, it would have looked tighter. A nylon strapping band just in front of the seam over and under the tank would do more than a 4 by 4 to keep the plywood from deflecting, which it probably would not at this water pressure. A 4 by 4 however introduces complications, from whether or not is is safe for interior use, to the tendency of 4 by lumber to twist and bow, taking the plywood with it.
Click to expand...

I stand corrected then. Nice build & nice brick work! Looking good!


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## Coln

Assembled tank in final position today. Def a two man job to align all the bolts, panels etc
Used five tubes silicon and put metal braces on the corners, I take ideas on board and it can only
help. Still on schedule to fill tank on sunday, hard day there's a cold one with my name on it in 
the fridge


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## imusuallyuseless

Looks great :drooling:


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## Coln

Filled today have got small drips from side panel, hope to seal from inside


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## Coln

Decided to cut silicon back flush and seal the joints with epoxy. Silicon just does not adhere to
west epoxy at all, the epoxy does it's job but the silicon doesn't 
Filling on Sunday again, I didn't like the look with the silicon in the joints prefer the same all the
way round a the tank


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## Coln

Filled tank today so far so good if all is good fish in next weekend


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## Drowned

As I've never heard about such projects in my country, I wonder if it's cheaper way to set a big tank than a standard aquarium made of glass?

Anyway, looks amazing!


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## Coln

Way cheaper, 72"x30"x24" tank is about Â£450, this tank will be below that and is a lot bigger
but a lot of hours 'work'


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## Coln

:dancing: :dancing: :dancing: :dancing: :dancing: :dancing: :dancing: :dancing: :dancing: :dancing: :dancing: :dancing: :dancing: :dancing: :dancing: :dancing: :dancing:

Tank up and running today, lot of hours work to get here but the fish seem to love it
still loads to sort lighting and current stuff but well pleased, cheers Col


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## bell

looking good, i love the depth


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## Coln

Tank running for a week, all good still to sort out lighting
and have added another FX5 they are the boys!!


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## I3lazd

Looks great man good job!! :thumb:


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## Coln

Added more rocks and moved others, think this is the final positions maybe
Fitted 10 x 1.2watt led lights they are all on swivel arms so can alter the look
of the tank, pleased with leds low running costs as well


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## auratum

Beautiful!!!


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## Coln

Added more rocks and internal pumps, video not up to TFG but 
hope you can see everything


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## alanvickiuk

that looks amazing i would love to make something like this in the future 

great work


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## BinaryWhisper

sweet project.

You say you sealed the seams with epoxy, could you expand on that for me? Did you just bolt it all together and then brush a couple of coats of epoxy on the seams? Do you think you you can still separate the panels?

I have read 100's of threads on ply tanks and it appears to me that going though the trouble to make the separate panels rarely works out. I know it is much easier, and cheaper, to make a strong water proof box if it can just be fiber and resined together as a unit with no thought to being able to disassemble it. A well build fiber reinforced resin on ply box really needs very little, if any, bracing as long as it is not overly tall.

So what are your thoughts now that you have built one?


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## Coln

As the silicon wouldn't adhere to the epoxy cut silicon flush and put on matting in all the internal
corners and added coats of epoxy until it was all smooth.
If I had to take tank apart would have to cut all the corners, that would be a thought.
I fitted metal braces at the top holding the panels together and when it was full of water
there was pressure on them so think it better with some bracing.
Would build another but not for a while.....


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## Coln

Latest photos of tank, have added more rocks and algae is slowly starting on them which I want 
as the fish can graze on it. The volume of the tank is actually 300 gallon and have insulated the tank with quality 70mm foam. Still getting air in the eheim filter but everything else is good


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## Sapper

I would love to have the skills and funds for somthing like this! This is awesome! :thumb:


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## jb1234

I may have missed it but what are the dimensions of the tank?


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## R-DUB

Love this build. Very nice job! Fish look healthy and happy. Cheers! :dancing: :thumb: :wink:


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## Coln

170cm wide, 73cm high, 110cm deep, It's acually 300 gall increased size after starting post,
Had a small leak but have emptied tank and well coated the problem.


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## tripn

A++++ Awesome build man... I am green with envy!! :thumb: :thumb:


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## TNprogrammer

Cobain,
I too am looking at using the West Systems epoxy. I have a couple of questions. Do you mix the 105 with anything like one of their hardeners, or just use it straight out of the can? Also, their website doesn't give coverage rates. Any idea how much square area a quart will cover at proper thickness?
Thanks.


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## Coln

TNprogrammer said:


> Cobain,
> I too am looking at using the West Systems epoxy. I have a couple of questions. Do you mix the 105 with anything like one of their hardeners, or just use it straight out of the can? Also, their website doesn't give coverage rates. Any idea how much square area a quart will cover at proper thickness?
> Thanks.


I used the 105 with 205 hardener, dont go by the coverage on the website that must be okay for boats but not sealing and bearing weight in tanks if that makes sense.
The epoxy is sold by weight here 105 1kg with 205 0.2kg looks to be about quart size as nextup is 105 5kg with 205 1.2kg
My tank's area was about 5m2 and 10kg 105 with 2.4kg 205 would have done and that is with a thicker layer on floor of tank.
West epoxy is a bit on the expensive side but very little odour and I found it okay for a first attempt with epoxy.
Mistake I made not putting thick enough coats on meant more rubbing down and extra coats, not using different colours on coats ie one blue next black so can see coverage easier ( saw that in IceBlue's tank after I did mine )
If you do decide on epoxy buy a box of disposable gloves and if you get some epoxy on a glove change it or it gets messy and I used cheap brushes and just used them once
and binned them, good luck and feel free to ask as you go, Col


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## Rivermud

based on your specified measurements you tank is actually 375 gallons


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## auratum

Rivermud said:


> based on your specified measurements you tank is actually 375 gallons


US or Imperial gallons?

170cm wide x 73cm high x 110cm deep = 1,365,100 cubic centimeter 
1,365,100 cubic centimeter = 360.62 gallon [US] = 300.28 gallon [UK]


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## Coln

I think it's 300 uk gall now, tank size changed during construction but wanted to keep thread
name the same for peeps keeping up to date.
Did a rescape after some territory disputes, a lot calmer and have put main lights on 
for longer to get algae on the rocks


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## rwolff

wow, everything looks good. except for the rock decor. maybe after it gets more algae on them, they will all blend in well, but it doesn't work for me.

I suggest get a one or two really big round rocks and have the others scattered around them instead of having them kind of piled up. the big rock(s) will give added dimension and will truly show the tanks hugeness.

but the rocks r cool..i kinda am in a bit of envy.


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## Rivermud

i roughed it to 70 inches instead of 67 inches.. thats where the extra 15 gallons came from.. just a flub on my calculations. and yeah whenever i hear gallons i normally assume US gallons since only a few countries use imperial gallons and only Britain and Ireland have it as an official measurement and quite possibly scotland but **** if i know... my bad again


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## Coln

Rocks have got some algae on them now and all the fish feed on them.
Really pleased with tank and the led lights at night are cool but hard to
get a photo.Video link below


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## severseas

Nice Work!

I didn't see any details on the glass installation. Did you use glass or acrylic? How thick, and how did you seal it?

Thanks!


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## Coln

Thanks, used glass 6.38 laminate and siliconed into the frame similar to photo


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## impeza

nice tank setup..a lot of good info!!


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## sulcata2big

thats an amazing tank, im sure *** seen it on another site.

mick


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## Coln

Yeah, its on a Lake Malawi uk site


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## Coln

Long overdue update


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## Coln

Added more pipe to rock piles for height but no weight gain, looks a lot better


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## Coln

Shows how much I know, piles of rocks like that do not work.
I'm going to fix sandstone for the background and have small
height of rocks round the base, prefer it already and only half done


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## iwade4fish

Someone should make that a feature tank in a forum!!!


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## Coln

:lol: :lol: :lol: you have some crazy ideas danny


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## iwade4fish

and this forums DIY section is full of them!!! :lol: :lol: :lol:


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## Chunkanese

Love the music in your new update. I also like your new rock set up, half the fun is just rescaping in my opinion!

I have also decided i will build one of these tanks 10 years from now when i own my own house. Until then i will have to stick with a 6 footer.


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## Coln

Have added three big rocks on top, fish are going all the way up the tank now, can't believe its coming up to three years since tank was made bigger still adapting the lighting mainly LEDs but still use the metal halide to get some algae on the rocks


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## SoDakCichlid

That looks so cool, Great work!


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## Coln

Thanks, it's hard to get photos of the tank to do it justice


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## vann59

Wow, looks great. The rocks are very dramatic now. Like an underwater 'stonehenge'. It would look good to perhaps stain or paint the window trim.


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## Coln

The wood is varnished to match the house finishings which are yellow pine should have made that
clearer in original post.


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