DIY Refugium
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I bought my current tank used 2 months ago. When I bought the tank it included a sump - wet/dry filter loaded with bio balls. After reading various posts on Reef Central I decided to build my own sump. The old sump was 12 X 12 X 24 and was just barely small enough to fit through the cabinet doors sideways and still turn inside the stand so that it could be used. The stand that came with my tank has a center support which leaves me with two doors that measure 16 inches wide. When I started to design my new sump I had several goals in mind:
1.) Get rid of the bio balls
2.) Incorporate a refugium
3.) Slow flow rate through the refugium
3.) Increase the volume of water of my sump
4.) Be able to install and remove the sump without removing the center support on my stand.

I sketched out a design and ordered some plumbing parts from . Next I went to a local Acrylic materials supplier to price the Acrylic. (Tap Plastics has a store here in Bellevue, WA ). For $6 per square foot they would cut the 1/4 inch clear acrylic to any sizes that I wanted. I also bought two types of acrylic cement from Tap Plastics.

The cement cost me about $10 between them. The first can of cement has the consistency of water and is used to assemble the sump. The tube of Weldon 16 has the consistency of maple syrup and is used to seal the seams after the sump is constructed to make sure it is water tight.






When I ordered the Acrylic I ended up with 19 individual pieces of various sizes. After cementing the first few pieces this is what it looked like.








The acrylic went together very easily. After about 45 minutes I had the sump half done.




The design I came up with was to connect two different cubes together using a pair of 1 inch bulkheads and a PVC union. The first cube would have the drain from the tanks overflow box, the skimmer, heater, the return pump and a Mini-Jet 606 Power head that would pump about 100 GPH to my refugium which would be in the second cube. When the water level in the refugium reaches the level of the bulkhead it simply spills through the bulkheads and union into the first cube again. Each cube is 14" X 15" X 18". At this size each cube can easily fit through my cabinet doors, and it increases my sumps water capacity by 17 gallons over my old sump.  Here are the finished cubes.


Since this is my first experience working with acrylic I decided I had better test it out in the garage to make sure there were no leaks. So I filled it up to the level the water would reach during a power failure, and let it sit in the garage for a day.


While that was sitting I went to Lowes and bought 50 lbs of playground sand to use for my sand bed. Now it was time to make the switch. Since my old sump was in the way there was no chance to test fit the new sump inside the stand, but fortunately my calculations were correct and it was a perfect fit. After I got it up and running then ran to my Local Fish Store for some LIVE SAND to seed the sand bed with and some Caulerpa (macro algae).  When I was looking for the sand I just wanted to make sure I got small grain size and I tried to avoid Silica. Since silica dust can be harmful the playsand mix advertised on the bag that it contained no silica. Here is a good article about sand beds that I read.


The light I installed for the refugium was a clamp on camping light fixture from Home Depot with a spiral fluorescent daylight bulb that is rated at 6500K. It consumes 19 watts but is rated as a 75 watt bulb. The fixture cost $5.29 and the bulb cost $7.49.  It has worked great.



This picture was taken 4 weeks after the refugium was set up.  If you compare this with the picture above you can see my macro algae has probably grown to 3 times the original amount I purchased.  You may also notice that the water level in the refugium is now higher.  I added a PVC elbow to the bulkhead in the refugium to raise the water level to make room for more macro algae to grow.





I have had a few people request a schematic drawing in personal messages, so I thought I would just post it here.



Hopefully my artwork will make sense. When the water first flows in from the overflow I have a shelf with holes drilled in it so I can put some carbon in if I choose. After passing through the carbon and the holes in this shelf the water has to rise over a small wall and then pass under one the goes to one inch from the bottom. The other half of my drawing shows the return pump chamber. The water enters through an opening one inch from the bottom, then flows over one wall and under another and over one more before reaching the return pump. 

I spaced the baffles in each of these chambers one inch apart, if I had it to do over again I would have made them a little farther apart (1 1/2 or 2 inches) because now the water flow through the baffles is fast enough to take some micro bubbles all the way through to the return pump. It is not a big problem, but it just bugs me that any bubbles are getting into the tank. If the baffles were farther apart the water would flow through more slowly, allowing the bubbles to rise to the surface easier.


I went to my local Tap Plastics location and spoke with one of their acrylic guys. He recommended the two cements that I used. If you need a source to buy them they also sell the cements online.

He suggested the capillary method described here to cement the acrylic sheets together.

He recommended the Weldon 16 to seal and reinforce the seams after the acrylic was assembled. The Weldon 16 has the consistency of maple syrup. To use it I tipped my sump up on one edge at a time, ran a bead of Weldon 16 along the full length on the seam, and then let it dry for 15 minutes per edge while the sump was propped up between some 4x4 posts to keep the Weldon 16 from running. Something like this.

If anyone is thinking of an acrylic DIY project this is an excellent how to booklet online: