Wood Tanks?? Do they work... You bet

[Pegasus]

Hi everyone,

Recently submitted and article in the Technical/DIY section on All Glass Tanks. Here is a follow up. Please note that words in caps are not shouting, just very important points. Safety is important when handling glass, so take care.

This topic is not a new one by any means, and was discussed fully on the Krib website way back in the early nineties, but my successful attempts were 30yrs prior to this.

As mentioned in my other article, I take no responsibility for your actions.

The tank listed here stood for 4-5 years without problems or leaks.

You don’t need to make a tank of glass, almost anything that holds water will do, take wood for example. In an emergency, or for breeding, use a drawer, or any container lined with poly. Just make sure the heater is safe.

Back to the topic. As mentioned in another article, some years back I built a tank of 4foot by 4foot by 4foot, completely of wood, not counting the viewing glass of course, which was 36x36. (600x600mm)

For the ambitious among you, here’s how I did it.

The frame as such was 3x3 (75x75mm) pine, and all joints were half lapped or jointed and glued and screwed with stainless steel screws. NOTE. Avoid boric treated wood and such. My worst subject of all time was woodwork, but I managed, but seek help if you need to, it’s a great deal of water once filled.

Your aim is to create a complete box shape ready for the outer cladding, much like the old angle iron framed tanks used to look like, without the glass.

For the cladding I used 35mm high density flooring board, but you may want to increase on this size or use marine ply if you’re pretty well off. The front and rear top strips of 3x3 will tend to bend once the water is in, so put these the strongest way around, or use 4x4 if you feel unsure, the frame is never noticed and won’t be seen, trust me.

Avoid boards covered in laminates, as these over time can release toxins not good for your fish friends.

Note. All references to “Fastening†means screwed and glued.

Glue ALL boards when attaching to the frame, and attach by screws only, no nails, and place screws not less than 50mm apart along each of the panels, all the way around.

As the panel screws are on the outside, they don’t need to be S/Steel, but must be at least one and a half times longer than the thickness of your boards.

Fasten the baseboard first, (the bottom) to your frame making sure it doesn’t protrude beyond the frame at any point. Dress up if reqd.

Now fasten the rear board to your frame making sure it is flush with the framing, and again has no overhang. The sides, when attached will overlap the edge of the back edge giving a nice finish, while the front panel when finished (wait for it) will overlap the edges of the two sides. If you have the facilities, or can get it done, you can rebate or mitre the edges for a better appearance. (I didn’t, and mine looked great)

The Front.

The front, when placed into position, should overlap the two side edges, and be absolutely level with the top of your frame.

Now the tricky bit.

You need to cut a viewing area into the front panel, (I used a jigsaw) and you may need help here. It can be square, or rectangular with rounded corners if you wish.

I made like a picture frame of “L†shaped pieces to fit on the inside to hold the glass in position. These are really cosmetic, as the glass will be bonded to the front panel later, but my advice is to fit them as they help to avoid bowing.

These “L†shapes should be rebated to slightly over the thickness of the glass so that when fitted they hold the glass much like a picture frame, but not be that tight that they squeeze all the silicone sealer out when tightened up. (see later) This rebated stock is a standard item at your local h/ware shop. Use 2x2 if you can get it, it won’t be seen.

Just to clarify. These pieces go on the INSIDE of the front board, not the outside.

The size of the viewing hole you remove from the front board should be smaller than the glass front you will be inserting.

I made my hole 3†smaller all round, which gave the glass a good area to sit on and a good area for sealing.

You could of course fit the glass BEFORE you assemble the front, but not a good choice in my view.

Fitting the front glass.

As mentioned in my other article, I’m a bit of a daredevil when it comes to trying things out, and in my case I used ¼†plate glass, but if you’re nervous increase on this.

Note. Clean the glass with meths or white spirit before fitting. Any dirt or finger marks could lead to leaks.

Place the glass on the inside minus the “L†shaped bits. Position exactly where it will actually go and mark the area, not forgetting to allow the correct margin all way around. Now apply a good amount of silicone sealer to the area of the front panel inside your marks. Go on, shove a bit more on.

Now get the help of your mum, or someone, and gently lower the glass into position.

Don’t worry about the sealer spreading for the moment, just make sure the glass front is where it should be.

Just a note. The Krib site states that the silicone sealer will not adhere to the wood. I don’t want to start a discussion on this subject, but mine sealed and adhered perfectly, as stated, for 4-5 years untouched.

NOTE, VERY IMPORTANT.

When placing the glass inside, imagine you are glazing a window. Push too hard and all the putty spreads out leaving areas to leak. It’s the same here. You are aiming to create a thickness of sealer around a ¼†thick or more between the glass and the front wooden panel. You’ll see the sealer through the glass and will be able to tell if you have the glass uneven, or it’s not sealed somewhere.

Smear any extruded sealer on the inside to form a nice finish. CAREFUL. When smearing in this manner take care of the glass edge which may be sharp. Ideally you can cover this sharp edge with sealer.

Leave it for a half hour to skin, then fit your “L†shaped bits and screw them into position. You may want to apply a little sealer to these pieces along the inside of the recess, but it’s not important. Like a cylinder head on a car, screw them evenly, a bit here, a bit there. DONâ€T screw one up all at once, fit them and work around each one bit by bit. Common sense should tell you when all is right, so I won’t pursue the matter, but your care here could mean success or failure.

The screw holes you made in the front panel will have to be filled, and once done the front can be clad with self adhesive contact fabric as used for kitchen shelves and such, but in my case I used rippled hardboard which gave a brilliant appearance once varnished. Your own imagination comes in here, tiles, shells, you name it, just make it so good that your mates will gasp with envy. You can also create a picture frame look by fitting ornate picture framing around the viewing area and outside edges. Go for it, splash out a bit.

I’m going off the subject, but mine was in my shop. I had two hundred plus tiger barbs in it, nothing else, apart from the old 14†plecostomus and a few cory’s.

Customers would come in and stand gasping and spend all day looking at my tank, many leaving hours later and not bought a thing, but this is good business, they always returned spending big. The sight of 200 TB’s schooling in a tank this size with this magnitude of depth is a sight you never forget. I was offered 500 pounds sterling for the tank (1960s) big money then, but I refused. (Now where’s all those bits of wood I had)

To continue.

Hold on you guys, you can’t leave the inside like that.

All flooring has been treated in some form or other, so it has to be sealed, and after spending a fortune trying to find the right stuff I arrived at this.

Your country may have different names for different products, so just shop around and you’ll find the right product.

I used a product called “Pondsealâ€, and it’s used for sealing the inside of outside concrete fishponds. It’s non toxic, doesn’t grow fungus hairs, which many of my earlier tries did, and it’s available from your aquarium shop or pond dealer, hopefully.

Once dried, it forms a hardish skin of rubber like substance over the area it is applied to. I gave mine two coats, leaving two days in between each coat. Make sure the top edges of your boards are fully sealed, this is important.

The stuff I used was called “Aqua Blue†and gave a great appearance to the inside of the tank. Ensure EVERY nook and cranny is completely sealed, even the unseen areas around the “L†shaped bits.

Problems.

Well, not counting the 2cwt of gravel to fill the base, only one really, and that was planting. I had to don my wetsuit, mask, and snorkel to do it. Ha Ha.

Seriously, planting was awkward, till I made up a grab arm that gently placed the plants where I needed them. You DEFINITELY need a Plecostomus or something similar. Mine was 14†long and kept the glass and sides sparkling. Never once did I have to clean the glass in five years. Think of the area, and make your fish work. Some for the sides and flat surfaces, rocks and things, others for the plants, more for the gravel and bottom, and others for the top. Paint a living dream of a tank.

Heating… WOW… Power bills. I used three 250wat heaters with their own stats, as I learned early in life not to rely on one heater or one thermostat. Also one heater works harder and longer to maintain temp than three, plus if one fails you don’t lose your mates, and you get a better distribution of heat, ie, no cold spots, no white spots, ha ha. Place the heaters as low as possible, but not touching the gravel. Heat rises, and placing heaters high in a tank causes cold spots, no matter how much air you have flowing from your filters and airstones.

One of the major causes of white spot is….. Geez… That’s another story. Get you’re A into G Bill, concentrate.

The tank was fitted with an U/G filtration system of my own design, and had a 250gal hour circulation system that sprayed the return water over the surface. The fish loved it, and I can’t ever remember losing one. Algae was no prob, my Pleco saw to that, and the interior never deteriorated or harmed the fish in any way. Plants, I can’t remember them all, but it was so dense I had Myriophlum and Cabomba, Aponogetons, Amazons, Vallis, Madagascar Lace, growing over six foot long, in just a short time, and I use to spend more time “Gardening†my tank than anything, as plants grew so fast I could hardly keep up. (Excellent for the shop sales though). Pygmy Chain Swords would shoot the length of the tank in just a few days, along with Vallis and ferns.

I awoke one morning to find the surface of the water covered in flowers from the Aponogetons, something I had never seen before.

Lighting was two four foot Growlux.

Brilliant stuff. Dream about it, Think about it, Make it happen.

Well, this old guy has rattled on enough, hope this helps someone, and you can get further info if you need it, just contact the board, or e-mail.

Also hope the site doesn’t mind these long articles of mine.

Best Regards

Pegasus NZ.

[Caryl]

FNZAS members can check out the Aquarium World May 2000, page 22, for an article by Max George about his African set-up made out of 18mm construction plywood with fibreglass reinforced corners and resin coating for the inside. No details like Bill's article but an interesting article all the same.

This 600 litre corner tank has recently been moved to his workplace, as he is shifting house, but most fish survived the shift (as did Max). I think he lost two.

[Warren]

Hi Pegasus,

I'm currently building an aquarium using a similar method. I had considered using all wood (except for the front glass), but chickened out due to the size and seismic considerations.

I have settled instead for a RHS Steel frame with 19mm Plywood sides fitted to the RHS members. The whole lot is then fibreglassed and sealed (epoxy resin is not waterproof!). The 19mm front glass fits inside the frame also. The RHS frame is galvanised first of course.

The aquarium is 3000mm x 1200mm x 1000mm (LxHxW) and will weigh in at about 4500kg when full (including tank/gravel/water). Due to its weight I was worried about it cracking on a corner join in a decent earthquake. At least with the construction method used it will be the last thing standing after the house has fallen down.

Anyone who wants detailed construction drawings for their reference can email me an I will send you a big .pdf file.

[Pegasus]

Hi Warren,

What a great project. Rolled Hollow Section was obviously the way to go for a tank this big. Hope you are on the ground floor due to the weight

Some pics would be choice if you have some.

Kelly Tartons beware, you have competition approaching

Regards

Bill (Pegasus)

[Warren]

Will send photos when finished.

Floor has 8 new piles under it. The piles are set in 500mm x 500mm of conrete, - didn't want them to move. My current tank is set on 6 piles - no concrete. It only weighs about 2000kg's and it sunk a bit at one end after 6 months. Luckily I'd used adjusters on top of the piles so re-leveling the tank was not a problem.

[cees]

Will send photos when finished.

[Warren]

No Hurry, is likely to be 3 months at least until the finished tank is planted out and looking good. This could be overly optimistic at the rate it is currently going (costing too many $$)! Will then submit a step-by-step photo gallery of the tank as it is made.

[Pegasus]

Hi Warren,

Got any future plans for what you might be putting in your new tank, you're gonna have heaps o room. The gravel and plants alone are gonna cost a small fortune, let alone the fish

You too may also may need your wetsuit to plant it out as I was joking about, but in your case it might be true.

Regards Bill (Pegasus)

[Warren]

The Tank will be an Amazon Biotope containing only plants found near Manaus in Brazil. It will also of course have Discus in it as well as a few other decorative local Tetra's (Rummy Nose, Cardinals, Rams, etc).

The plants will not be a problem. I am already growing on some of my propogated plants in my fishroom. I have a 1200L 8 foot tank that provides a 10L bucket of plants every week. There'll be no problem there.

If you have Takashi Amano's Nature Aquarium World - Book1, you can see a similar style I will be copying on page 138/139. It will require a little modification to become an Amazon Biotope however.

The fish won't be a problem either, I'll just breed some more. It would cost more than the whole tank setup to buy all the fish. I plan to buy 2-3 pairs of quality imported Discus and breed lots. I plan to have about 30 adult discus in this tank + 500 Cardinals and 500 Rummy Nose. None of the above mentioned fish are difficult to breed. I've bred heaps of Discus and some Rams in the past, but not Cardinals or Rummy Nose. Have had good success with Black Neons however and the others are supposed to be very similar.

The lighting is turning out to be the biggest single cost for the system. I haven't got it yet, but it looks like it will cost between $3-4k. I need 6 x 150W 6500K Metal Halides. I'm currently looking at using 20x58W Fluro's instead (way cheaper) but don't know if they will reach the 1m depth ok. They have the same lumen output so they should.

Water will be salinated RO. I use my own mix to stabilise the RO water as not a drop of tap water goes into the tank (we have a 6-8ppm Phosphate problem with our tap water). I mainly follow the Dupla system (but make all my own fertilisers and stabilising salts) to get good algae free plant growth.

The new tank will effectively be a big brother to my current tank. The two will actually end up being linked on the same filter system.

Will add more as the project develops.

[Pegasus]

You certainly have it all meticulously planned out Warren. What a fantastic project, and I, as many others, can just about see the amazing sight it will be once finished. Sound like your going to need shares in your local power company, the heating bills alone will possibly be staggering.

I am in absolute awe, and thank you tremendously for your posts and hope you will keep us all informed.

Just a little confused about the salinity bit, and the RO abreviation?, thats if you have time. Do the species you mention need the salinity, I know they like it pretty soft and slightly acid.

Excellent stuff Warren.

Regards Bill (Pegasus)

[Caryl]

Hurry up Warren, we wanna see the photos!! I am sure the finished set-up is going to look spectacular. I have a copy of the Nature Aquarium World and was able to look at the pages you say your tank will be based on. Will it be ready by conference? :lol:

This may sound stupid but...if lights don't reach down to the required depth, why can't you use underwater ones? Are they not the right sort of light, or not strong enough?

[Warren]

No, tank still has a long way to go. The empty tank will be very close to finished by conference, but will still be at the shed I'm building it in. Then of course it has to be filled. It will take my RO unit over a week to fill it (it only makes 400L a day!) The tank will have 3300-3500L of water in it. Then the plants will have to establish (3 months minimum). It will not look really good for some time. It looks like we are going to make a special page for it where I can put a project history (including photo's) for other DIY people to check-out. The page will not be developed however until there is a decent amount of content to add to begin with. There is nothing worse than looking at a fairly barren web page! Once the tank is finished I will assemble the info and post it in a page. I can then add extra pictures as the tank matures.

[Warren]

The water will not be salty at all.

All water must have a certain amount of hardness, both carbonate and general. If not the pH will not be stable. Water hardness is due to alkali earth metals (Calcium Chloride, Magnesium Sulphate, Potassium Sulphate, Sodium Carbonate etc). These are salts. Most people think of salt as the stuff you put on food. This is only Sodium Chloride. There are many other salts ase well. When I talk about salinity it is nothing like sea water.

The water is still very soft. I use only 1-2dH Carbonate Hardness and 2-3dH General Hardness. I can get away with this because I am doing at least 50% water cahnges every week. If not, the plants and fish waste products would exhaust the Carbonate Hardness salts and there would be a pH crash.

I add enough of the correct types of salts to give pH stability and macro nutrients for the plants. In effect the water has salinity (most water does). The salinity is so low however that it can be deemed almost pure.

African tanks have a lot of salt in the water. This is why the pH is so high. The water still tastes fresh, but it is still more saline than South American Water.

RO stands for Reverse Osmosis. This process removes nearly all dissovled salts, gases, organics and heavy metals from the water. It has no pH stability.

[Pegasus]

Thanks Warren for your very informative replies. I'm not too clued up in this aspect of water and such, but I'm certainly better informed now, and when you mentioned salinity I must admit I thought of Sodium Chloride. Silly Billy :oops:

Hope you don't mind me starting the other thread with the announcement of your name and tank, but I'm hoping we can get other big tank owners to tell us about their projects.

All the best with your project.

Bill (Pegasus)

[Rob]

Warren, have you investigated using compact fluorescents for your tank. I'm not talking about the energy saver type used to replace domestic light bulbs, more the strip type (look like a very narrow elongate 'U'). I see them advertised in TFH magazines and saw some when nosing around one of the local MaserTrade shops. In stock they only seemed to have 86's, not sure what other numbers are available. They're definitely more expensive than standard fluoro's, not sure how they compare to metal halides. They're supposed to have a higher light output/watt than standard fluoro's.

If you were using metal halides would that mean you'd have an open top tank?

[Warren]

Have actually used them. They run much hotter. At the time only colour 84 was avaialble. I did not find them as good as a full length tube. The colour faded faster too. I only got 6 months out of the compact fluro's compared to 12 months out of full sized ones. The higher running temperatre probably shortens the usefull bulb life. They are a lot more expensive! (I get 58W full sized tibes for $4.87ea but the compacts are $22.50ea).

I'd have to check the colour 86 bulbs to see if they have the correct colour rendering specturm. I have now moved to using colour 96 lamps. They have even higher colour rendering capability than colour 86 lamps. They are 3 x the price however!

[Benny]

pegasus,

have you seen on the net for the plans of making an aquarium completely out of plywood. I thought I might try and make a 5x2x2 tank for my growing giant gourami and fire eel. With regards to what to paint on the plywood to stop it from falling apart, on your tanks do you use epoxy paint?

[Pegasus]

Hi Benny,

The product I used to seal everything was called "Pondseal" and when applied it forms a firm rubbery seal to the inside of the tank. They may have a different name for it over here, as I was in the UK at the time of building my tank. It (Pondseal) was designed for outside ponds and pools, but was a great success on the wooden tank I made.

Some products I tried fungused after a short while, or peeled off but this product passed all the tests and never peeled or split and stood up to the rasping of the Plecostomuses.

Two foot deep might be a bit shallow for your Goramy, because you won't be able to take advantage of the full two foot depth as you have to leave an area to support the glass, and I recommend a minimum of three inch (75mm) all around supported against the wood front which would only leave the viewing area of 18" (450mm) which might be a bit small on a tank the size you are planning.

Going to 5'x3'highx2'wide would be good, but 5x3x3 would be better. If you have the room the deeper size would be a better approach. Email me if you need some construction help.

Regards Pegasus (Bill)

[Warren]

I am using standard packing grade prlywood. It is 19mm thick (3/4 inch) and I'm using 2 layers. This is covered by copstrand fibreglass and polyester resin. I am not using epoxy resin as it is not water proof. The top layer is gelcoat (black) used to seal the tank. The gelcoat is very hard and quite resistant to abrasions. My only concern is cracking the gelcoat if a rock ever falls over.

It may be better to use the stuff Bill is mentioning. I've seen it before and it is available in NZ. It is used on Ponds and Pools to seal the concrete. It is not cheap however (probably at least $100 for a tank the size you propose) beacuase it a very speciallised paint.

I'm using Gelcoat because a freind can bo it for me really cheap with a spray gun. Likewise, the chopstrand and polyester get sprayed on using a special machine. All you then have to do is roll it out and you're all done.

[Pegasus]

Hi Warren,

My project was in no way as technical as yours and in many cases it was a "Try it and see" approach, but I knew from the very start that the front and sides would bow and that any form of paint or resin would crack as the tank flexed. This was the reason for using the product I did. Luckily I got the construction right first time

Just out of interest, how are you going to heat that tank of yours. Must have shares in the power company

This is my biggest concern once I do start up again, as I don't want to dabble, I want a real fish house setup with perhaps a couple of dozen tanks, to start with at least . (Don't tell the missus )

I'm working on a heating system that will add nothing to my power bill or incur any additional costs apart from the initial installation, uses no fuel of any sort, requires no maintainance, will supply any amount of individual tanks without mixing water from one to the other and is not dependant on the power company if the power fails, and on paper it looks pretty good, but would not be suitable for general use. Sounds impossible, but most things can be worked out if you think hard enough, and I've done a lot of thinking

Now if only I could get the lights to work for nothing I'd be on to a winner

BTW. I did several tests on bits of wood covered in various resins, paints, and sealers. I dropped them into an established tank and weighted them down. Many fungused after a short while and were unsuitable, but the Pondseal didn't and this was another reason I used it. Might be a good idea to do some tests before you go the whole hog and splash out on expensive coverings. Many of the silicone sealers in the early days suffered from fungus attack, but I was fortunate enough to do the trials for Evo, the adhesive company in England who supplied me with as much sealer as I wanted FOC. None worked until they added the fungicide and from that point on it was all go. This was before Dow Corning had brought the sealers onto the market and before all glass tanks became popular.

Regards

Pegasus (Bill)

[Caryl]

I was interested in your second to last sentence Pegasus when you said you had problems until they added fungicide. I thought you had to make sure your paint or sealant did not contain fungicide as it was toxic to fish? Obviously not or are there different sorts of fungicides?

[Pegasus]

Hi Caryl,

Not too sure about the tech details, could have been a fungicide or a fungus retardant, but all I know is that it worked. The guy came into the shop one day and made me an offer I couldn't refuse, namely to test these new sealers they had developed for glass free of charge, and if I did they would supply me with all the sealer I needed. Many didn't have the strength, others broke down after time, and others fungused. They never told me the "secret ingredient" but it certainly worked as far as the fungus was concerned.

Regards

Pegasus (Bill)