From: steve@celia.UUCP (Steve Tyree)
Newsgroups: rec.aquaria,alt.aquaria
Subject: [M][R][Long] PVC Matrix for Captive Reef Live Rock
Keywords: coral reef marine live rock pvc matrix circulation
Date: 8 Sep 92 20:24:18 GMT
Reply-To: celia!steve@usc.edu (Steve Tyree)
Organization: Rhythm & Hues, Inc., Hollywood


 I have constructed the pvc matrix manifold for the right 1/3 section of
my 180 gallon reef tank. The actual construction was more difficult than
I had expected. I used schedule 40 pvc joints and schedule 80 3/4 inch
(inside diameter) electrical grade pvc pipe. The entire matrix is pri-
marily made up of joints. I water tested it last night and no leaks
were detected. The 4 corner joints also have a 90 degree 1/2 inch thread
joint into which I installed a plugged extender. These 4 legs should be
enough to support the entire matrix and no additional support will be
required. This matrix will be elevated about 2 inches, since the tank
is 24 inches tall this loss of height should not be a problem. You
could use 1/2" pvc for shorter or smaller tanks. You should have some
previous experience with pvc construction before attempting to make a
matrix. Assembly is tricky. Also, the costs of pvc and glue was 30 us
dollars and the water pump was 50. These costs could be cut by using
1/2 inch pvc parts or purchasing parts via mail order. The matrix is
primarily a option for large tanks which need additional reef circu-
lation.

 pvc parts   (12)  3/4" slip x 3/4" slip x 3/4" slip [T]
             (9)   3/4" slip x 3/4" slip x 3/4" slip x 3/4" slip [cross]
             (4)   1/2" thread x 1/2" slip [male adapter]
             (4)   1/2" slip [plug]
             (4)   3/4" slip x 3/4" slip x 1/2" thread  [side outlet]
             (1)   3/4" slip x 3/4" slip x 3/4" thread  [water in T]
             (13') 3/4" ID schedule 80 pvc tubing.
             (1)   4 oz pvc glue.

pvc schematic

  CCPOOOPTTTPPPPPTTTPPPPPTTTPPPPPCC
  C       T       T       T       C     C - Corner side outlets
  P       P       P       P       P     P - PVC pipe 3/4 inch ID
  P       P       P       P       P     T - pvc T's
  T       X       X       X       T     X - pvc crosses
  TTPPPPPXXXPPPPPXXXPPPPPXXXPPPPPTT     O - water input T
  T       X       X       X       T
  P       P       P       P       P
  P       P       P       P       P
  T       X       X       X       T
  TTPPPPPXXXPPPPPXXXPPPPPXXXPPPPPTT    note - corner pieces have 1/2" male
  T       X       X       X       T           to female slip converter with
  P       P       P       P       P           1/2" male plug installed. 
  P       P       P       P       P           These extensions are adjust-
  T       X       X       X       T           able feet.
  TTPPPPPXXXPPPPPXXXPPPPPXXXPPPPPTT
  T       X       X       X       T
  P       P       P       P       P
  P       P       P       P       P
  C       T       T       T       C
  CCPPPPPTTTPPPPPTTTPPPPPTTTPPPPPCC

 Here is a schematic for my 180 gallon reef acrylic tank with the center
overflow chamber as installed by the tank builder. The design was reco-
mended by the retail store manager. He said that it provided lots of 
water flow over the surface of the reef. The only problem is that the
flow is real light in the bottom rear of the tank. Originally I had
buried submersable pumps in the reef rocks in the back of the reef. This
did not seem to work very good.

 Key for the following schematics 
         :::   water flow
          <    water flow to left
          >    water flow to right
         high  water flow occurs high up in tank
       middle  water flow occurs in middle vertical area of tank 
         low   water flow occurs in lower area of tank
         ret   water return from main pump
        over   overflow sponge filter chamber
         OO    pvc matrix water input pipe

========================================================================
|                high   |     |          |     |   high                |
|    ::::<:::::::::::::<| ret |   over   | ret |>:::::::::::::>::::    |
|  ::                   |=====|==========|=====|                   ::  |
| :                                                                  : |
|: middle                                                      middle :|
|:                                                                    :|
|:                                                                    :|
|:                                                                    :|
| :::>::::::::::::::::::::::>              <::::::::::::::::::::::<::: |
|                low                               low                 |
========================================================================

 Here is a schematic showing the pvc matrix manifold circulation system.
All water flow originates in lower area of tank. The first matrix will
be installed in the right 1/3 section of the reef.

                                                   New Reef Manifold
                                                    Subsystem Area
========================================================================
|                       |     |          |     |**OO*****************  |
|                       | ret |   over   | ret |*    *    *    *    *  |
|                       |=====|==========|=====|*********************  |
|                                               *    *    *    *    *  |
|                                               *********************  |
|                                               *    *    *    *    *  |
|                                               *********************  |
|                                               *    *    *    *    *  |
|                                               *********************  |
|                                                                      |
========================================================================

 Now I will need to drill holes into the matrix. I will use a 1/4 inch
diameter drill bit. One question I have is should the diameter of the
holes increase as the head length increases ? I will have holes aimed
at the floor of the tank with the direction of flow out towards the
perimeters. Also, I am thinking about drilling holes at junctions with
the attempt to direct water up into the reef. The other complication 
deals with how to direct flow towards the front and towards the right
side of tank simultaneously.
 In summary, any design improvements discovered will be installed into
left 1/3 matrix. The finished product is very sturdy, clean and will
last a long time. Probably overkill. The matrix is 5x5 rows and a small-
er dimensional matrix might work. This should solve the animal trap pro-
blems and allow algae grazers to still get at bottom of tank. The flow
will help move detritus to front edges and additional flow directed up
into reef will improve reef circulation. The number of live rock bottom
contact points should be decreased due to matrix bottom. The only pro-
blem will be in hiding the matrix itself. I might put a panel on the 
outside acrylic that matches the stand. 
 Note - Assembling the matrix is difficult. One wrong move when putting
        assemblys together might result in a hardened matrix which is 
        uneven. Will update this post with additional information when 
        matrix is installed and operational for awhile.

 Steve Tyree - Reef Breeder