Upflow Calcium Reactor build

[framerguy]

Ok, I’m going to document my calcium reactor build (for real this time...this is not a test!)for anyone who may be interested. It is a dual chamber upflow reactor. I built it bigger than it needed to be because if my tank can’t be bigger than Terry’s, then by golly the stuff that runs it can! I used 4 ½” clear acrylic tubing and 1/4” clear acrylic sheet for the base. I used 1/4” black acrylic to the flanges (because I had it). You can get it from .. http://www.estreetplastics.com/Acrylic_Tube_s/45.htm ..E street plastics. I got the thumb screws from… http://www.4coral.com/diy_parts.htm ..4 coral. The PVC and speed fittings all came from Lowes.

I’ll show you the final product then tell you how I got there…


I began by building the base. I decided how far I wanted the tubes to be separated then measured and came up with 13” wide x 11” deep x 10” tall. Cut the pieces to size.
Top: 1@ 11” x 13”
Front/Back: 2@ 13” x 9 ¾”
Ends: 2@ 10 ½” x 9 ¾”
Bottom: 1@ 7” x 10 ½”

Cutting acrylic on the table saw is extremely noisy. Always wear ear and eye protection!!!

I used a table saw to rough cut the pieces 1/8" oversize. Make sure to rough cut each of the same widths at the same time so they all come out the same size. I then set up my router table with a straight bit so I could joint each edge. I set up the fence at distances from the bit so each piece would come out the exact same size. For instance, for the 13" wide pieces (which were overcut to 13 1/8” ) I set the fence at 13 1/16 and passed one side through, then set the fence at 13" and passed the other side through. It is tedious but necessary for exact dimensions. It creates very clean and smooth sides for good glue joints. A jointer can also be used but you may or may not get exact sized pieces.

The method I used to glue the pieces looked like this...


Since the reactor is finished and I didn't take photos of this step, I created a mockup to take a photo. Imagine those finish nails are toothpicks (I am out of toothpicks now). I used four plastic speed squares. Notice the corner of the square has been mitered. Locate the square so that the side will be flush with the end and tape the square in place. Set up the side and used a spacer made of toothpicks to create a gap and use another square to hold it up and straight. Then carefully fill the gap with Weld-on 16 glue. As if by magic the glue is sucked into the seam. Let it sit for a 30 second count then remove the toothpicks and the seam welds itself. Let it sit for at least an hour before gluing the other sides, this is time consuming.

Once the front, back, sides and top are in place then glue the bottom in. Glue it to the front and back only, you’ll see why in a moment. I chose to put my pump on the left side so I put the bottom to the left side so it would leave the right side of the bottom open for plumbing parts. The bottom is inset about 1/8”. Mine will be sitting on a concrete floor and I didn’t want the bottom to interfere with sitting on a possibly uneven surface.

Next open the sides up for access to plumbing and the pump. I used a laminate trimmer for this.

Make a jig out of plywood the size of the opening plus the size of the offset of the bit from the edge. Clamp that onto the box and route the opening. Doing it this way gives greater strength to the structure than merely gluing strips around the edge instead of using a solid piece, although the strip idea may be adequate.

The base should be complete.

[framerguy]

The next mission is to decide how tall the tubes should be. I had a 50” piece left over from another job so I cut it in two 25” pieces. 18” would have been more than sufficient and in retrospect it wouldn’t have been so hard to reach to the bottom of the tube once it is in place. If I had it to do again it would be 18”.
CUTTING THE TUBING: Cutting the acrylic tubes is relatively easy on the table saw. You will need to make a sled to provide support for the pieces while you rotate them. Mine looks like this...


I would like to re-emphasize the importance of wearing eye (preferably full face) and ear protection while cutting acrylic. And guys, although it may be tempting in this hot weather, it's also a good idea to wear a shirt. Those little plastic pieces hurt.

Ok, cut the acrylic tube pieces by pushing the sled with the acrylic piece until the blade just cuts through the tube. It's handy to have an assistant hold the sled once the acrylic is in the blade. Then rotate the tube until the entire cut is made. Go slowly to avoid cracking the tube.

Although simply gluing the tubing right to the top of the box may be adequate, I made an acrylic ring for the tube to sit in for added strength. Here is a photo of the ring in place…


If you decide not to use the ring, drill the bulkhead fitting holes before gluing the tube in place.

Creating the rings uses the same method as making the flanges so I will go into making flanges now. First let’s cut the parts to size. Cut two squares (For the rings) 5 5/8” x 5 5/8” and four squares (for the flanges) 6 5/8” x 6 5/8”. I used clear acrylic for the rings and black acrylic to the top flanges. You can use clear or black for all of them, it doesn’t matter. Leave the protective paper in place. Using a straight edge, find the center by making a line from corner to corner. "X" marks the spot! I didn't use a protractor although it would have made things a lot easier...I lost mine in the move and haven't gotten another. Instead I very precisely measured from the center mark and made tic marks where the outer edge of the router bit would be. I will go into building the top flanges first, then the rings will use similar but simpler technique.

Making the 6 1/2" flanges: Mate two pairs of squares and tape them together one on top of the other with masking tape. First I marked where the thumb screws would be located. There is an "X" already, so I divided each section in half and made another "X". So you should have a nice star pattern of lines now all meeting in the middle. The circles of thumb screws will be 2 ¾ " from center so make a mark on one of the lines at 2 ¾ " from center.

Slow the drill press speed down to 1/2 speed (that's 1500rpm for mine). Drill through both pieces at center with a drill bit the size of the nail pin.

One note here, if you intend to tap holes for the thumb screws then use the 17/64 bit. If you plan on using the screws and wing nut, then use a 5/16” bit. Put a 17/64 (if you are tapping) bit in the drill press. Locate the acrylic so the bit meets the mark you made for the screw and set the pin into the wooden drill table. Next carefully and slowly drill through both pieces , then rotate the acrylic to the next mark, continue until all holes are drilled. Drill the other pair of 6 1/2" pieces the same way. In this photo the outside is already cut. If I do it again, I will leave it square to do this so I don’t have to change the bits so often…


Separate the acrylic and peel back a little paper at two corresponding holes and scribe into the plastic something to tell you those two screw holes are mated. I scribed the words "top 1" and "bot 1" on one pair, and "top 2" and "bot 2" on the other. In a perfect world it shouldn't matter and the holes should line up no matter which ones you match, but my world isn't perfect so I have to adapt .

[framerguy]

To cut the outside diameter I used a ¼” router but with a ½” shank. A larger bit of 3/8” would probably have had less vibration. Increase the drill press speed to top speed (3600rpm for mine). Place the bit along the outer tic mark so the bit is to the outside of the mark…

…then set a pin in the center hole.

Using the press’ stop feature…


…set the bit to drill 1/8” into the acrylic…


Then set the bit to drill all the way through…


Go slowly and hold the pieces tightly as the bit wants to spin them for you…don’t let it! Cut all four pieces before moving the pin. Once the two top pieces are routed they are done for the moment, so set them aside.

[framerguy]

Next let’s make the inner opening and rabbet of the bottom sections of the flanges. I created a rabbet for the tube to sit in for added stability. Since the pieces have been mated and marked make sure you are cutting the rabbet into the BOTTOM of the acrylic. Set the pin so the outside of the bit is aligned with the inner part of the 2 ¼” tic mark. Set the depth stop for 1/8” deep then route the rabbet ring…


Test fit the rabbet on the tubing, if you need to make adjustments in the pin setting and redo it, now is the time. (I had to). Cut the second piece before moving the pin.

Now cut the inner edge. Move the pin location so the bit leaves a 1/8” rabbet. Cut the opening in two passes. On the final cut make sure you go very slowly just before the pieces separate so the bit doesn’t grab. There will be a small burr that will be filed away.




Now that you know how to cut the outer and inner parts of the circle you can cut the two rings to mount the tube to the box. The inner part of the circle should fit the outside of the tubing. Once the rings are made then glue them to the top of the box aligning their outside edges about ¼” in from the back and sides. See photo above for final location.

[framerguy]

Next let’s make what I call a bubble plate. Bubble plate: Here is what we are making...

Cut one of the 4 1/2" pieces of acrylic into a 4 1/2" diameter. You should be a pro at it by now! After it is cut, mark cris-crossing parallel lines 3/8" apart to make a grid. It should look like a checker board. At each intersecting line drill a 1/8" hole all the way through. Next use a countersink bit...


and countersink each hole so it looks like the picture. I set the drill depth stop just as the bit hit the table.

In one of the bubble plates, drill a 7/8” hole offset to one side for the recirc tube. Lay that bubble plate in the right hand ring and mark the location of the hole then drill two 7/8” holes for the bulkhead fittings.

To make the bulkhead fittings I used ½” plastic electrical conduit male and female fittings. They aren’t tapered and can be screwed all the way together. Since the treads aren’t long enough on the fittings to add a gasket you will need to use aquarium silicone to seal them, then screw them together and let it dry at least 24 hours.

[framerguy]

In the left hand ring drill a hole for the size speed fitting you are using. I chose a ¼” speed fitting with a male end. I drilled and tapped the hole for the threads. See the photo below.



Next make the spacers for the plate to sit on. (See above photo). They are strips of acrylic cut 2 ¼” long and glued to the inside of the tube. Once dry then glue the bubble plate in place. Once that is dry then it’s time to glue the tubes in place. Cut a ½” PVC pipe to length so it leaves a space about 1 ½” from the top of the tube and locate the right tube so the hole and bulkhead fitting align and glue the tube in place. It may not be necessary to glue the recirc ½” pipe in place although I did. Glue the left tube in place and leave to dry for one hour.

While that is drying you can cut the gaskets. I got the ¼” neoprene material locally, but heavy pond liner material may work also. Use the bottom flange to mark and cut out the material. Then drill the holes for the screws…


Drill out the holes for the top plate if you plan on tapping the flange holes to screws. Drill the holes in the top with a 5/16 bit so the ¼” thumb screws have extra clearance. Then tap the holes in the bottom flange pieces with a ¼”-20 tap.


You will notice I already glued the flange in place so if you haven’t done that yet then it’s time to do so. Remember to put glue on both pieces and give a 30 second count before joining the pieces.

Now let’s drill the top for some fittings. The right tube will get three fittings while the left tube gets one. I used ½” 90’s for the speed fitting in the left tube and for the CO2 recirculation fitting in the right tube top. If you have access to ¼” speed fittings with a ¾” male thread then use a threaded 90 fitting. Other wise use a plug drilled and tapped for the normal 3/8” threads. Drill and tap the plug if necessary and glue the plug into place in the 90.

[framerguy]

To drill the rabbets for the fittings I used two forstner bits…


Use a 1” bit to drill the rabbet and a ¾” bit to drill all the way through. Position the top plate in place (remember to align the marks) and decide which direction the fittings will face. For the left tube simply drill the hole in the center. For the right tube you want to catch the edge of the center hole with the outside edge of the rabbet so the hole will be off center. For the small 90 degree effluent speed fitting, drill and tap the hole. Use Teflon tape and screw the effluent fitting into place. Now glue the 90’s with attached speed fittings into place aligning them in the direction you like so they are between the thumb screw locations. I used the PVC fittings so any CO2 that accumulates at the top could be directed out through them.

To make the pH probe port I used a ½” speed fitting. I removed the inner plastic insert and gasket with a screwdriver, then drilled out the fitting with a ½” bit. Replace the gasket and insert. If you have a tap big enough for the threads then drill and tap the hole. I don’t, so I drilled a ¾” hole and used a plastic nut and silicone to hold the fitting in place. Make sure to place the hole so it doesn’t interfere with the recirculation tube. Here is a photo of the top…


Notice the valve fitting in the left tube and a simple coupling in the right tube.

I used filter foam material to make the media barrier. I cut to shape and had my wife put it in because my arms were too big (which is why I would use shorter tubing next time). Put the flange top in place and install the screws.

[framerguy]

Let’s move on to the base plumbing. Here are photos of the finished product…




I carefully measured to the center of the input and output of the pump. I used an Eheim 1250 pump. The intake side of the pump connects to the recirc tube. I put ball valves on each bulkhead so I could close them to remove the pump for cleaning. I made precise measurements for the ½” PVC and cut the pieces to length. Choose appropriate size tubing for your pump. The fit should be snug but easily removable. I used 5/8 tube for the intake and ½ tube for the output. On the pump intake side of the plumbing, I drilled and tapped a hole for the CO2 input tube. I used a “T’ fitting with a ¼” speed fitting for the CO2 recirculation tube. I used a threaded/slip 90 with a barb fitting for the water input fitting and the pump input fitting. On the output side I used a threaded/slip 90 and ½” barb fitting. I needed a barbed 90 but didn’t have one so I made one with CPVC pipe and fitting. The tubing slips easily over the pump fittings and is held in place with pipe clamps. Here is the final product again…

[framerguy]

Notice I used the strip method to make the end pieces of my box and not the much stronger solid piece with cut out. Like I said, if I had to do it again I’d make it right. I used 1/4” tubing to connect the effluent outflow from the right tube to the intake in the bottom of the left tube. I also used the same tubing to connect the CO2 recirculation fittings. I think that’s it. If there are any questions I’ll try and answer them. It’s hard to determine what it cost to build it. I got the pump from E-bay, the tubing and flat acrylic was leftover from another job, and the fittings were stuff I had on hand also. Almost certainly you will save money building it yourself, plus you have the satisfaction of having done it yourself.

[Loverotties]

Nice job!