Instructions regarding construction of breeding tanksBy Tim Gautrey
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I have just completed a little project in between the others on the go to build some breeding tanks. This has been very successful and so I thought it would be helpful to share the method of construction with you all, hopefully saving you money!
The method is simple, cheap and effective. The object is to build 4 breeding tanks as a single unit, which can sit on a shelf, mount on a wall or almost anywhere you have space.
Over the next few days, I will be building another one, and will keep a record of the progress for you to see how it is done.
1 sheet of 12mm polycarbonate sheeting (3m x 1m) 2 tubes of aquarium safe silicon 1 roll of masking tape 2 pieces of glass. (For this build, the measurements will be 7"x36" but can be cut to suit your own requirements) 1 100W heater (Short type, Hydor do a nice one just the right size for this build) 1 Small powerhead filter (Fluval 1 would do, so long as you can connect a pipe to the outlet) 1 pack of Fluval 2 filter media 1 length of 2" electrical surface trunking 2’ length of pipe to fit the outlet on the powerhead. (I used the tubing from my gravel vacuum!)
With a lot of the above materials, you will have enough to make several of these units, so keep them handy!
Decide on the measurements. For this build, I will make the unit 18" high x 6" deep x 36" long. this size fits very well onto wall shelving and will hold 4 x 2 imperial gallons.
Mark and cut the polycarbonate sheeting to the sizes. When cutting the sheet, cut through the center of the ribbing over the size you require and then trim back to the rib on both edges. (See drawing 1A,B,C & D) Be very careful not to break through the ribbing. It is a bit of a tricky thing to do, but once you get the hang of it, it’s easy. (I used a small angle grinder with a steel cutting blade to trim mine back, but a sharp craft knife and glass-paper will do the job just as well)
For this build, the back panel will be cut at 18 x 36, ribbing running horizontally two side panels at 18 x 5 1/2, ribbing running vertically bottom will be cut at 6 x 36, ribbing running horizontally upper-bottom at 5 1/2 x 35, ribbing running horizontally center divider is cut in two parts, one at 11 x 5 1/2 and the other at 6 1/2 x 5 1/2. ribbing running vertically.
Fill the ends of the ribbing on the upper bottom panel at both ends and smooth off. Now things get a little more difficult! Use a drill to make holes in the polycarb as follows:
Drill a row of 10mm (7/16th) holes through the one skin only, in one of the end panels 1 1/2" from the bottom edge and another at 16 1/2" (Drawing 2 & 3) and fill both ends of the ribbing with silicon and smooth off. (don’t block up the drilled holes though!) These holes will be the channel for the water flow from tank 2 to tank 3.
Drill a 20mm (11/16th") hole 10" from the bottom of the other side panel through both skins, and another hole the same size as the tubing from the powerhead 17" from the bottom. (Drawing 4) Again, fill all the ribbing with silicon and smooth off. In this instance, seal the broken ribbing inside the large holes with silicon. This will take the pipe from the powerhead in tank 4 to tank 1 and let the power cord out.
The two center dividers need to have a row of holes drilled at the bottom on one side and the top on the other side as drawing 5, 1 1/2" from the bottom and 5 1/2" from the bottom. This allows water flow from one tank to the next. As above, seal top and bottom with silicon and smooth off.
Once everything has been cleaned, de-burred and drilled, you are ready to start assembly. If you have never used silicon before, practice on some offcuts until you can get a nice even bead running along the edge of the polycarb. The nozzle can be trimmed to suit yourself, the smaller the nozzle the finer the bead you get. I would recommend that you have a nozzle of about 3/8th inch trimmed at a 45 degree angle for best results.
Start by arranging the pieces in order and pre-cut the masking tape into roughly 4" strips. You will need quite a lot of strips, so make about a dozen to start with. You need to decide which side you want the pump now. All the water flow will depend on whether the pump is on the left or right. I instictively install my pump on the left, but you might want to have it on the right.
Take piece 4 and stick some tape strips under the back edge, leaving about 2 1/2" free. Take piece 1 and run a silicon bead along the bottom edge. Place the bead firmly onto the back edge of 4 and run the tape up over the join onto the back panel. (This will be very unstable and an extra pair of hands may be useful to hold this join while you get the next piece ready.)
Take piece 2 and bead the back and bottom edges with silicon. Stick a few more strips of tape onto the underside of the bottom on the LHS and also on the LHS of the back panel. Carefully place 2 onto the bottom LH edge, tape and then bring the back panel onto the bead and tape there too. Press firmly on all joints, squeezing the silicon out of the sides of the joint. You now have the start of the unit!
Don’t hurry this, take your time to get it right, it will save problems later. Adjust the joints to align the edges flush on the outside and press firmly into position. You should have the LHS and Back sitting on top of the bottom panel, and, if you got the sizes right, the front edge should be flush too.
Ok, so far, so good. The silicon will stay workable for around ten minutes, so once the joints are right, you can use the back of a spoon handle dipped into soapy water, or your finger to smooth the inside into a curve across the joint. If there isn’t enough silicon squeezing out of the joint, run another bead down the inside of the joint to ensure an even curve all the way along. when it’s done, it should look like image 6!
Be very careful now, as these joints are still unstable and will slip out of line if you’re not careful. Now take 3and bead the bottom and back edges as you did with 2. More tape and sit it on the RHS of 4. You now have three sides and a bottom. Line up the edges and bead it in as previous. You may find it easier to lay the assembly onto the back panel now.
Now mark the center of the back panel with a pencil or felt pen. this is where the bottom center divider, (6), goes. Check that the flow direction is correct, with the top row of holes on the opposite side to the pump. Bead the back and bottom edges and place on the center line, pressing it firmly against the bottom and back panel. This cannot be taped into place, so you may have to re-position several times before it’s right.
Take piece 8, the glass front panel. bead all the edges of the polycarb, bottom, sides 7" up, center divider. carefully align the glass panel onto the beads and tape in place on all sides. smooth the inside round now, as you won’t be able to get to it easily later.
Leave the assembly to dry for an hour or so, or until the silicon has skinned over. This will help to stabilize the assembly for the next phase. Take the electrical trunking and cut a piece long enough to fit between the front and back panels. (Should be about 5 1/2 "). Remove the top cover and trim off one leg, leaving an L shape. Silicon this in place level with the bottom of the top row of holes, leg facing upwards. This is a bit fiddly, but it works. The bottom two tanks are now complete!
Measure 7" from the top and mark on both ends. This will mark the top tank base. (Assuming the measurements and cuts are right, it should sit straight onto the bottom center divider.)
Bead the back and both ends of 5. Also run a bead along the top of the center divider. Again, a second pair of hands is useful here. Ease the side panels outwards slightly and slide 5into place. The polycarb should give enough to do this without breaking the seals if you are gentle. Release the sides and press firmly against 5. press 5 firmly against the back panel. As long as the silicon hasn’t gone off too much, the panel should push into the rounded beads on both sides. If it doesn’t, just trim them with a knife where the panel fits in, so that they don’t stop it sitting tight to the back. (Difficult to explain, I know, but I hope you can understand what I’m getting at.)
Bead and fit the center divider, (7) again making sure that the flow runs the right way, (top holes same side as the pump). Press firmly into place and bead the inside of all joints.
Now you can fit the other glass front, (9), by beading all the edges and carefully positioning and taping in place. All things being correct, the top should line up all round. If the glass is slightly below the top, you can adjust it by sliding it up a little to line up flush with the top of the polycarb.
Allow the silicon to skin over before fitting the other two trays to the top tanks. Seal these in place and leave overnight to allow the silicon to fully cure.