My 360g plywood tank - The official build log

S

SamIam

[OK finally figured out how to post pics in the gallery! (The applet never loads, and I just saw the other tabs to let you add pictures :rool eyes: )

I'll start with a little background. I bought a house about 3 years ago that was a rental, had original 1979 Shag carpeting w/stains, original H/W heater, at least 3 layers of stickem tile, you get the idea. I took it down to sheetrock, replaced all doors, molding, baseboards, celing texture, floors, plugs, switches, light fixtures, raised ceilings, etc. Anyway, one of the things I did was converted a bedroom to an office, and built along one wall a book shelf, computer closet, and 72g Bowfront. I always wanted an In-Wall tank, and all the construction made it a perfect time to do it.

I looked at several options, but couldn't find a tank to fit the space 7'x34". Most tanks are 2 or 3 feet deep and 6 or 8 feet long. I read about plywood tanks for a couple of years, and I thought it would be a fun project. So I decided to do it. Knowing what I know now (1/2 way finished), and knowing wht the glasscages tanks go for, I might have just bought one of thoes instead. That's a good option if your not very good with woodworking.

In the middle of my house renovation, mom sent me a card saying your almost there, and in side was a picture of me working at my mom's house helping grandpa with drywall. I was about 3 feet tall. So I've been doing this stuff for a while,a dn just have a natural ability to figure stuff out. :)

That tank has been set up for about 3 years now, and it turned out great. My office is the favorite room in the house. I'm in here 10+ hours a day as I work from home. When I bought the house I had always thought the spot in the living room would be a great place for an in wall tank. Well, all the other interior projects are done, so I decided to start on the tank. Here's what I put in the space when I moved in.

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That's taken from the living room, and the fireplace is on the Left, Foyer and dining room is on the right. I planned this for a long time, and over a year ago, I drew up this plan:

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The actual tank is not much different than this. The stand is 7' long, 32" deep (to fit through the front door), and 36" tall.

The tank is 7' x 32" x 35" tall. Instead of a overflow box on the side I did a wall that goes all the way across and takes up 9" of one end of the tank. I'm surprised the tank came out so close to my origianl design since I did it so long ago.

Ok. I'll stop there, and start with Construction in a new post.]
 
[Here's some of the prep work that went on:

The stand started with a trip to the scrap yard. I found this cable spool, and had it cut in 1/2.
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That cost 5$, and I used the spokes as the upright to the stand.

These were in another scrap yard, and cost about 10 bucks. We used them for the top and bottom of the stand.

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All of this was rusted, so we sanded them down and painted them with an oil based rust preventer paint. Christy took on the painting and did a great job.

We took all this down to the farm for a weekend to build the stand. My uncle has a big shop that has all the tools we needed.


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Christy helped out some, and went fishing the rest of the time.

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[I built the top and bottom rectangles, then fit the upright posts into the corners. They didn't fit, and I had to grind one corner to make them fit. Then I welded every edge.

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Then we cut the center supports to sit on top of the channel bar, and also cut out the tank bottom supports. The corners have so much welding on them, I didn't feel a need to add any angled braces. There's really not that much horizontal stress on a fish tank. The weight is straight down. Then the inside supports we cut and set on top of the channel bar instead of inside. Again, the force is down. I also added some supports in the center to support the tank bottom. Since this is a plywood tank, it needs supported just like an acryllic tank would. I'm putting 3/4" oak plywood on top of the stand, and shiming that to get it perfectly level. Then the tank bottom is 1" plywood as you will see.

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Ok, she did help out a lot . . . :uhoh:

And the almost finished stand:
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Edited By SamIam on 1094493656
 
[The stand went together nicely, and cost about 30 bucks compared to probably over $200 using new steel. I had actually planed to make it a bit smaller, but Christy wanted it to be big. So, I uped the dimensions, and come to find out, ... it didn't fit the space. I had to knock out the side of the brick fireplace. If you build something like this I would suggest you make sure you can make all the turns, etc. Also think about where you place it in your house. a 600gal tank on the corner of a slab foundation will break it. Keep that stuff in mind.

Anyway, here's what I did to prep the space:
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Started by cutting out the carpet, it was rotten from the 135, and smelled awful (remember this was new when I moved in, and the 135 was setup for about 2 years, with your occasional spill, but nothing major. It helps to have a brother that owns a flood restoration company. :grinning: Christy was scraping paint, etc off the floor so the stickem tile would be flat and level.

Here's what I ended up with:
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The vent goes to the pantry in the kitchen on the other side. That's going to draw in cold air from the house and let some of the noise escape to the kitchen. You can see frinm the pics, I used each space for something. As you can see I pulled out all the sheetrock, and replaced it with backerboard.

The bottom of the sheetrock was also rotted. If you do this I would recommend you use backerboard as well. Greenboard is cheaper, but it's just sheetrock with a vinal instead of paper coating. Backerboard is an improvement on concrete board. It's lighter, you could throw it in a pool for a month, pull it out, and hang it with no problems.

Here's the fireplace I had to knock out. There was sheetrock behind it, and I riped that out as well. I later read that backerboard will let moisture pass through it and rot the boards (your talking years out however), so I put up 3 or 6 mil plastic sheeting, and then put the backer board on that.

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I also ran another 20A circuit. (If you don't know what your doing, then hire an electrician) I'm an electrical Engineer, which means I have a slightly higher chance of getting electricuted than the average person. :laugh long: I got lucky, and everything went ok.

Then I also ran 3 sets of 5/8 tubing to tank. 2 go to the garage where I have 2 50-gal drums for fresh and salt, and one goes to the drain stand pipe for the kitchen sink. I should be able to do water changes by turning a few valves and pumps on and off. The other line is for top off water. I got 2 dosing pumps on reefs.org for 40 bucks each. They are 12V DC, and work great. I wasn't sure if it would pump through the attic, but I tested it yesterday and it works great. The pumps are about about the size of a pint glass, and compared to the reef filler I had planned to use they are quiet.]
 
[Anyway, on to the tank! I started by deciding what height the tank would be as that is a key factor for everything else. 34" Is what I finally decided on. That meant I needed to brace the corners or use 1" plywood. I decided on 1" plwood, and started calling around. I found it eventually for $60 a sheet from the plywood and door manufacture corporation listed in the local sources post in this forum.

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To cut the plywood, I used a circular saw. Not the best tool for the job, but at 1" each sheet was at least 60lbs, not to mention 4x8' and not that easy to move. I went and bought a new 40 tooth blade to do the cuts. I just took it nice and easy, and the came out pretty good. Then I spent hours and hours and hours sanding.

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Then I got an electric sander. :nod: It takes a lot of tools to put something like this together. I have NPT pipe taps from harborfreight.com from 1/4 to 1-1/2 inch FNPT. I also got a rubber mallet, corner clamps, bar clamps, 1/2" drill, biscuit joiner, planer, 1/2 inch bit to drill large holes for the bulk heads. If you have a budget for the tank, keep this stuff in mind.

So I cut the bottom and sides:

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Then I cut the ends. I sanded the edges to fit, and it came out great. Once I can get the pics off my camera, I'll post the assyembly pics.]
 
[To build the overflow box, I needed to know how big to make it. I decided to just section off one end and make the whole thing one overflow, but I still had to decide how deep to make it. For this I ordered my first attempt at plumbing supplies:

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I also have flexible PVC that I'm using for the pipe runs. Most of the fittings are 2". Anyway, I built mini durso standpipes and sized the box like so:

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Then I marked and drilled all the holes, and then assymbled it. Here's the finished product:

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I put one hole in the wall in case I decide to add a closed loop later. I also have 4 bulkheads where I really only need 3. No harm in putting it in now, and just not using it. One of the great things about plywood vs. Glass.

Another side project popped up. I was looking at a solar tube for the tank to suppliment the lighing, and allow me to run the halides for maybe only 4-6 hours a day, at 10 amps that's a huge savings in electricty and bulb replacement. Plus you get real moon cycles and sun rises on the tank. In doing that, I came across a couple of good threads on RC in the large tanks forum. People were doing it with success. I had always thought it would work, but 3 years ago, people were saying, no, you just loose too much light, etc. (Don't believe everything you hear)

Anyway, I found a Velux skylight 2X4 venting and electric. I could leave this thing open, it would close automatically when it rains, and would take care of the humidity problem. However, it costs $600. I almost got one, then I came across this at home depot:

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The outside was broken, and the guy told me to offer the manager 10 bucks for it. (Originally $87) He took it, so I bought it. I got rid of the acrylic smoked panel, and there's another bubble under that that's clear. I'm also adding a 6mil double wall sheet of clear polycarbonate (Acryllic places have it), which is the stuff they use for greenhouses. It blocks UV, and lets the full spectrum through.

I still have to worry about venting the humidity, but 10 bucks vs 600, I just couln't turn down.]
 
[Oh yea, I forgot to add here's what the tank looks like now:

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As you can see, I got the two windows cut, the aluminum top back, and some sanding to do.

I also did a little work on the water prep area. Here's a picture of it' that's almost self explanatory.

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[Looking good! A friend of mine had a couple of Solartubes installed at his house. Even on a cloudy day, the amount of light is unbelievable. They are almost to bright at times. Keep of the good work.]
 
[Awsome pics and comentary, keep us informed of the entire process. I would love to tackle a project like this one of these days. :beerchug:]
 
[The braces across the top connecting the front and back are very important. I hope you have enough reinforcement around the frame of the tank itself. I had a 240 wood tank in my garage that I gave to a guy. it had 2x4's for the main structure and it still bowed bigtime when he filled it. He had to tack on some more bracing from the front to back. Here's a pic for you:

240 wood tank]



Edited By tesfeld on 1095093863
 
[Very interesting! The two windows are larger than I expected, and I feel a bit worried about the corner between the two. That looks like a real pressure point. Did you say they would be glass or acrylic? If acrylic, you could bond the two windows into a 90 degree, then affix it to the wooden tank and reinforce that corner.

The solar skylight confuses me. You said it was $600, but that was $87. Or do you mean they marked it down to $87 and still couldn't sell it?

What is the backerboard made of?

I strongly suggest you move that dart board for people with bad aim. :laugh long:]
 
[Thanks for the comments all, I'm in Denver this week, and I'm going to the Austin City Limits music festival this weekend, so I won't get much done on the tank. Anyway, a few of you had questions:

Solatubes, My mom as 4-5 in her house, and I agree they are very very bright. I won't have the polished aluminum reflectors they come with, but I will be using reflective mylar exactly like this guy did:
500g tank w/skylight

It should let me not have to turn on any lights until about 2-4 PM, and let them run till 10-11. (I'm not a morning person, sleep late and stay up till about 11) That means I should be able to use the halides from 2/4 until 8/10 so I only run them 4-6 hours, which should make a huge difference. I'll run the PC 03's around 8 hours a day.

As for the skylight the Velux electric skylight was 600, the one I got was $87, but because it was broken I got it for 10 bucks. I just couldn't pass that up. I still have the venting problem to fix, but it's really not that big of a deal.

Top Bracing, i agree that thoes cross braces are key. I tried welding them myself at first, but that didn't work, so I took it to a welding shop. It cost $60 but it was heliarc welded, and you can see just how thick the welds are from the picture. It's not going anywhere That will keep the top from bowing.

On the bottom there are biscuits and screws every 1-1/2 inches. I'm really not worried about it pulling apart. You have to keep in mind this is 1" birch plywood with no internal voids. I can flex the 3/4 stuff you buy at HD, but this stuff doesn't give.

Assuming the top and bottom are secure, the weakeast point then becomes the center. As Marc pointed out, that outside edge is a bit weak.

However, think about your glass tank. It's basically glass bonded with silicone, with 2 metal frames for the top and bottom. The only thing holding it from bowing is the strength of the glass and silicone.

When I add the two pieces of glass, I'm going to join them the same way with silicone inside the tank. In addition, they will have that wood to brace them. That corner will be more than enough to hold the glass, and it's going to give me a place to hide a return plumbing line. So other than the aluminum cap, there is no external bracing.

Tony, thanks for the picture, that was helpful to look at. Do you know what thickness plywood was used? It looks like 1/2 inch. I almost did the internal corner bracing like that tank does, but in the end decided on the biscuts. Although I could add it along the back before I paint.

I got most of your questions Marc but here are the others:

The front pannels will be glass, and I have pretty much decided on Acrylic for the bottom, back and overflow box. I hope to use silicone to comepletely seal off the paint from water. I could probably get away without the epoxy paint, but I want it there as a failsafe. Anyway, if it turns out right, then the water won't ever contact the epoxy paint, olny glass acrylic or silicone.

Not sure what backer board is made of. Has to be some form of concrete. It chews through sawblades like you wouldn't believe. Cutting out a plug will grind smooth a new jigsaw blade with 1/4" teeth. It would have been easier to use greenboard, but after researching it, I found out it's only rated for occasionally wet/damp areas. That and the rot on the old sheetrock pushed me to spend the extra money on greenboad. It's not cheap, at 10 bucks for a 3x5, but It was worth it to me.

:) Yea, on the dart board there's a story behind that. Brian got a little drunk one night at a party and put a hammer through the garage wall. So to make up for it they bought me a dart gun. Yea, I didn't quite follow the logic either, but I can't wait till they get there own houses. :devil2:

I have to unpack and get ready for tomorrow. Keep the questions comming, you may catch something I haven't considered. Once I paint, I think it will be too late to make many changes.]
 
[I've actually had some time at home after getting back from Penn state, and I got some work done on the tank. I painted a first coat on the outside of the tank to protect the wood from the humidity and occasional splashes. I didn't want anything warping or rotting the wood. Here's how that came out:

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The stuff on the inside is where I had extra paint and didn't want to waste it. Anyway, the paint smells awful. It doesn't even wash out of your brush with lacquer thinner. Plan on throwing your brush away. I bought 4 cheap ones for 8 bucks at Lowe’s, use them once, and toss em. Also make sure you have a respirator and long rubber gloves. It burns everything. My eyes even started stinging towards the end of a painting session.

It's also kind of hard to spread. It's very thick but also has a very low viscous friction, meaning it drips off the brush everywhere. :) That's what the spots are on the bottom of the tank. If you put it on too thin, then it doesn't coat evenly, too thick ad it makes huge sag lines. Once you put it on, it starts to dry and get sticky, so going back over it is also hard. I just ended up sloping it on there, getting a thick coat, and fixing the runs as best I could.

You have to let it dry for 4 hours before adding another coat but after 24 hours you can't touch it for 72 hours and you then have to sand it. So I put the above coat on, waited 3 days, roughed it up with 220 grit, and put a black coat covering the entire inside of the box. Then I waited about 16 hours and got the second coat on in Blue. I bought 2 different colors so I could alternate them and ensure even coats. This really works well and I would recommend it to anyone trying this. Here's what's drying in the garage:

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Jacob, I may have enough paint left over for you to do a sump. I'll know In 3 days when I decide if I'm going to put on a 3 or 4th coat.]
 
[Thanks for keeping us up to date. :smart:]
 
[I moved the tank inside to trace the cutout for the side facing the dining room. It looks a lot bigger in place. I threw a 5 gal bucket in there for sizing, and the camera makes it shine a lot. Under normal lights it's shiny but a dark blue.

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