Tank plumbing

[Ed Seeley]

Hi everyone,
I'm looking at a new tank for my new house. I have a great space under the stairs in my living room that will let me fit in a 5ft long, 2.5ft wide by 2ft tall tank! A friend's going to custom-make me a cabinet for underneath and at the side of the tank and the plan is to have the top open with 3 LED spotlights to illuminate the tank. This isn't going to be a heavily planted tank but a Tanganyikan tank (it's bascially going to be an upscaled version of what is in my Rio 180 at the moment) so the only plants in there will be a bed of vallis in the rear right corner. In the other corner will be a large pile of rocks and the rest of the area will be open sand with patches of shells.

The problem I'm having is this. This tank will be filtered (and heated) with an Ehiem 2128 I already have but I want to eliminate any pipework from inside the tank so I was going to fit an overflow in the corner and then have a fitting through the glass to connect to the filter and another for the feed back to the tank from the filter. However when the water level drops this will starve my filter feed won't it? As I don't have an open sump the only water level that will drop when the water evaporates is that of the weir chamber!

So is there anyway I can use an overflow with my ehiem filter?

Or should I just put two fittings through the tank walls and live with seeing those fittings inside the tank?

 

[foxfish]

Ed sounds like you need to drill the tank, either two holes in one end at mid water or one either end, one low one high.
I normally use two one end to get a nice circular flow.
You can buy nice looking threaded fittings from marine chandlers, some of these have barbed tail ends, angled ends or glue fit ends.... http://www.aquafax.co.uk/pdfs/03_cat.pdf

 

[Ed Seeley]

Ed sounds like you need to drill the tank, either two holes in one end at mid water or one either end, one low one high.
I normally use two one end to get a nice circular flow.
You can buy nice looking threaded fittings from marine chandlers, some of these have barbed tail ends, angled ends or glue fit ends.... http://www.aquafax.co.uk/pdfs/03_cat.pdf

Thanks for the reply. Definitely planning to have holes for the pipework but thinking I might not be able to run a weir and will just have to have holes in the tank side for the inlet and outlet. Will put them both in the rear right corner as I've found previously that this filter really belts the flow out and will circulate the whole tank nicely enough I think.

Was just thinking of having a weir as I might switch to a sump filter as the stocking in the tank increases but I guess I can always add that later as long as the holes have been drilled at the start.

 

[foxfish]

I love sumps! I love the benefits of extra volume, skimmed surface & hidden equipment.
A lot depends on the siting of the tank when it comes to positioning of a sump feed hole, I recently built a 2' cube that had a situation that allowed viewing from all sides (on a kitchen island worktop) so the sump feed was drilled dead center in the bottom of the tank. A simple 75mm pipe was used for the central overflow.
My own tank has a 32mm sump feed hole situated 150mm down on the right hand side because the tank is set in a false wall the flexible feed pipe that takes the water to the under tank sump is not visible.
Very often i install sump feed out though the tanks back but most often they are drilled in the base.
I don't like to much daytime flow because I feel you might be losing to much gas so you can get away with a 25mm hole however I always drill a 32mm just to be sure

 

[Ed Seeley]

Both holes will be in the side, the inlet to the filter probably about 10-15cm off the bottom, the return from the filter up near the top, probably roughly the same distance from the top of the tank. Then if I go down the sump route later I can just clean the tank down, add a square sump around those two holes and silicone them in place.

The tank will have a cabinet directly at the side where the external filter, and subsequently the sump, will be positioned about 18 inches below the base of the tank.

Will look at a 32mm hole for the inlet, but will probably stick with a smaller one for the return, unless you think I may as well go for 32mm for both? If I go with the sump I will be looking at a much more powerful pump than the external.

 

[foxfish]

Sump returns are best fed back over the top of the tank unless you use a non return valve to avoid syphoning!
I would use a 18mm return hole if you go that route - allowing for the fitting that will give you a 12mm actual hole.
I am on my phone at the mo but I can give you more details tomorrow if you need them.

 

[Ed Seeley]

More details would be good and non-return flapper valves will be used if I switch to a sump!

 

[foxfish]

Your overall plan sounds great Ed however - I wish I could tempt you into building a plywood & fiberglass tank with a glass front or even, front & one side if that will be visible.
Really not that difficult especially if you can get your friend to build you the box, the benefits are then huge not only from a security point of view but because you can drill holes anywhere you want with a standard wood bit & have no fears of cracking.
I will have time later today to talk but, pretty busy this morning, can you tell me the height & length of your under stair space?
Exciting project.....

 

[foxfish]

Hi Ed, I managed to find this one of a ply tank with a 32 pipe fitting drilled through the back & a pic of the overflow pipe before is was painted to match the tank.
The problem about non return valves is the amount of water resistance they produce & there is always that little uncertainly they wont work when the inevitable night time power cuts happens!

 

[Ed Seeley]

Was toying with the idea of a fibreglass back and sides as I will never be able to look through the sides. The only reason I've currently discounted it is that I'm probably not going to be in this house a huge amount of time and figured I can either re-use or sell an all-glass one but not sure how mobile a wood/fibreglass one would be?

 

[Ed Seeley]

The dimensions of the space is 92"(2.35m) long, 68" (1.73m) high by 37" (0.94m) wide. The sloping section is to the right hand side as you look at it. There's a short vertical section 20" (50cm) high on the right and a section of flat ceiling 36" (92cm) long on the left hand side. The rest of the ceiling then slopes down to the short vertical section at about a 45 degree slope.

The current plan is the 5ft by 2,5ft wide (though may go wider) by 2ft high glass tank on a high quality softwood frame about 2ft tall. This will then be fronted and carcassed out with oak to match the wood in the room. Where the tank stops to the side there will be the fish-stuff cabinet that will be used to house the filter. This will be about 4ft tall at the tank side and slope down to 20" on the other. Will give lots of room for a sump if I change over to that in a year or so.

 

[foxfish]

Hi Ed, a fibreglass tank is far more durable & movable that an all glass tank.

Why don't you go for a sump straight away?

You can use a polythene container or an old fish tank & you dont need anything complicated in the sump just a pump, a heater, a bag of bio balls & a power head.
I normally run the return over a sponge that is washed every week & I fit a sponge in front of the pump - real basic stuff really but, the benifits are fantastic.
I really like the fact that the main display is always kept full to the brim & the amount of bio balls you can fit in even a small sump will far outperform any external power filter.

 

[Ed Seeley]

Need more details of tank construction then, if you don't mind? How do I make it robust enough that the tank doesn't flex and how do I form the frame to sit the front glass in? Have a mate who's an ace fibreglasser, I'd just need to make the frame for him to work to.

I'm not going for the sump straight away as it'll be a lot of extra cost to sort the sump out and pump. And If I do the sump I'll do it properly as a static K1 filter followed by fluidised K1 so it's incredible easy to clean as well as very efficient and don't want to go to that hassle and expense when the Ehiem's there.

I've already got the Ehiem 2128 on a tank I'm about to mothball and it is a great filter that will also heat the tank. And as it's a Tanganyikan tank I'll only need a sump if I change the stocking as this tank will probably only have 25 or so fish in it until they breed! I might never need to put a sump on to be honest, but if I put a colony of Tropheus or switch to mbuna or something that will put a much heavier load on the tank.

 

[foxfish]

Basic carpentry skill required - use 18mm w.b.p. (exterior grade) ply to make an open fronted box, glue up all joints with polyurethane glue & use 4.5 x 60mm decking or s/s screws, pre drill all screw holes.
How you make the frame for the front of the tank is a matter of design preference & how you want it to look.
You could use hard or soft wood & glass the inside or as shown in my pic - offcuts of ply temporary fixed in place & then removed after glassing to leave a 3mm thick frame. This can then be covered in your choice of wood.
On a tank the size you want, you will need 2x1 wood bracing along the back edge to stop the ply bowing but probably best to use 2" ply strip all around the top edge & glass it in.
If you friend knows his stuff then it will be a simple job for him to glass the inside & get him to resin coat the outside to.
I think you will need 12mm float glass for the front, or possibly 16mm if you don't want a centre brace.
I have built 8' long tanks in a similar manner but actually built a complete box & then cut out for the top & front ply sections leaving a 2" frame.

 

[Ed Seeley]

Thanks for the info. Considering this carefully now! The woodwork and glassing is fine, but I'm a little unsure about the retaining flange for the glass. How large does that need to be and will solid oak be ok as that is the plan for the cabinet finish?

Also the glass - does it need to be toughened or laminated or just plain float glass? Ideally I'd like it braceless so will look at 16mm glass.

 

[foxfish]

The return flange should be the same size as the finished frame - so if you had a 2" oak frame, that could be fitted to box (glued screwed & Plugged) & glassed on the inside.
The reason for using scrap ply wood as a temporary mold for the glass fiber return edge is just to prevent the finished frame from getting stained during the glassing. (you could just use masking tape over the oak)
I get the float glass cut 10mm smaller all around, you can lay the box down on its front, apply a generous bead of silicone to the fiber glassed return edge & lay down the glass on top, then add silicone around the edges to fill the 5mm gap.
If possible I would also get the float glass edges polished otherwise be very careful when smoothing out the silicone with your fingers (the voice of experience!!).
You might like to get some optiwhite glass priced up?

Ed there is loads of info on the net although most just paint the inside of the box, I feel fiber glassing give a far more robust & safe tank.
You can google glass thickness requirements too...

Here is just one of many articles http://www.canadianaquariumconnection.c ... .php?t=529

 

[Ed Seeley]

Cheers mate (sorry, can't see your name in any of your posts),
I've costed up the wood and am seriously thinking about this. I'll need two (2.44 x 1.22) pieces of 18mm Exterior grade plywood, 10, 1.8m lengths of 50mm square timber, plus the oak for the visible fronts, the fibreglass and epoxy resin, the glass and a few tubes of silicone. The wood will come to about £60 so just need to work out how much fibreglass to get, and how much the glass will cost. Then I'll know what to do!

Not sure I'll bother with Optiwhite - will see what the damage is on the plain glass first!!! I have read a few articles and would definitely fibreglass if I do this.

Thing is this will not only be a bit cheaper but will also give me the look I'm after as it will be totally braceless (Braces will be on the back and sides behind the wood, not like on a glass tank), will have black back and sides (which I'd paint an all-glass tank with anyway!) and will allow to put loads of insulation into the frame to reduce heat loss to the walls around the tank. Will have to talk to my mate who was kindly going to do stand and see if he fancies doing the whole tank too!!!

 

[foxfish]

Great, I would use polyurethane glue to stick everything together, it comes in a tube that's fits onto a mastic gun just like the silicone, (available from B&Q).
Ply comes in sheets measuring 2.4 x 1.2 (8'x4') sheets vary in price but again B&Q will cut cut & supply at a good price.
I would recommend getting the ply pre cut as you will get accurate square edges & sizes.
I dont think you will need any epoxy for anything, you can get your friend to use some styrene in wax with some pigment to get a great finish on the glassfibre.
PS....polyurethane glue is an amazing product but, nothing - but nothing - will get it off your hands!! so budget for some disposable gloves too

 

[Ed Seeley]

Cheers for the info. I'm still not sure whether I like the idea of a wooden tank in my living room but as this is the only way I can afford an open topped tank I'm very, very tempted!

Here are the current plans;

First the view from the front;

This is the end view of the alcove and tank;

Finally the plan view;

The whole front of the tank and frame will be faced in oak cladding and the stand under the tank will have either oak doors, drawers or shelves - a friend who is an amazing woodworker is going to work that out with me. The frame will be 50mm pine, the plywood will be 18mm exterior grade plywood and coated in black fibreglass. Along the back you can see the horizontal 50mm plywood strengthening ribs. I'm thinking of adding vertical ones too to further reinforce the plywood. All the gaps around the ribs will be filled with 50mm Kingspan insulation to neaten everything off as well as reduce the heat lost through the back wall which is the exterior wall. I may even look at coating all the back wall (That above the tank) with kingspan that is coated in fibreglass. It will help with spalshes on the walls too!

To the side, where it's currently shown as empty space will be for the filter and to store stuff to do with the fish tanks. It will have either one large oak door, or two smaller ones for easier access.

Oh an I can't find the black bulkheads I've seen on some tanks like this. Anyone know where I can get them over here or do I have to order them from the States?

What do you all reckon? Would love to hear thoughts!

 

[foxfish]

Sound great Ed...King-span Polyurethane high density foam is seriously expensive if you go for the effective 75 or 100mm thickness where as polystyrene is very effective & cheap but flammable!
The ply & glass will have good insulation properties in themselves!
Re the black fitting - I can get them from my locale boat chandlery shop but, you can just use white & coat them with either G4 or gelcoat & wax.