Re: DYI Substrate Heating

                    Modified CPVC Substrate Heating
                    by Allen Sandifer
                    Orginal Design by Earle Hamilton

The orginal idea for the substrate heating system was derived from an
article in Aquraium Fish Magizine by Earle Hamilton. His orginal design
was a manifold system using 3/4" Ts and 1/2" cross tubes. Wanting to
keep everything small I used a continious loop system using all 1/2"
CPVC fittings and pipe. This design is an open system but could also be
done with a closed system like Earle's one model in the article.

Parts List:
    3 10' sections of 1/2" CPVC
    17 1/2" 90 degree ells
    2 Large Lee's Speciman Boxes
    1 Ebo Jager 50w 9" heater
    1 100 gph power head (the output is a little low should be 145+)
    2 1/2" slip unions
    1 Tube GOOP Plumbers Glue
      CPVC Cement & Cleaner


    The resivior was constructed by cutting the bottom out of one of the
    Lee's speciman boxes. Put a bead of GOOP Plumbers Glue around the
    bottom edge and slip this one into the top of the other one. This
    will give you a resivior aprox. 9 1/2" deep. Set this aside to dry,
    it will take aprox 24 hours.

Heatng Grid:

    The heating grid was constructed using the 1/2" CPVC pipe and the 90
    degree ells. I measured it out so that the grid tranversed the
    bottom of my 55g tank 6 times. This gave me aprox. 2" on center for
    the pipe. About 1" above the top of the gravel I cut the
    inlet/outlet pipes and install the 2 slip unions. The unions were
    only glued on one side. This allows for the inlet/outlet pipes to be
    removed for easier installation or removal. On the top of the
    inlet/outlet pipes I glued 2 90 degree ells to form the U to get
    from the tank to the resivior. Note: Remember to leave enough room
    in the U to fit over the hanger of the speciman box.

    outlet->| |<-inlet          waterflow -->
            | L_______________________________________
            |_______________________________________  |
             _______________________________________] |
            [_______________________________________  |  heating grid
             _______________________________________] |

                         1/2" CPVC Heating Grid

            The pipe comes out roughly to 2" on center
            Corners are 2 90 degree ells

    After all the glue was dry i laid the grid in the bottom of the tank
    and install the inlet, outlet pipes & resivior. I put the heater and
    the powerhead in the resivior and filled the system with R/O water.
    By using R/O water there is less chance of algae growing in the
    system. Distilled water would do the same thing. The entire system
    hold just a little over a gallon of water.

    The heater is set to 85 degrees and it is keeping the tank water at
    aprox 78 degrees. At the present time I am losing about a cup of
    water every 3 days. I have a cover over part of the resivior but
    there is still plenty of room for evaporation. It would be fairly
    easy to construct a lid for it from the bottom that was cut off the
    one speciman box.

    So far I am very pleased with this system. The only thing that I
    would do different is I think I would use a closed system using the
    heater camber from Rainbow Lifegaurd. The cost of this would be just
    a little more than what the 2 speciman containers cost, plus
    eliminate the evaporation all together.

    For those cold days of winter that we have in Missouria I also have
    a backup heater in the tank set to 77 degrees.

    My thanks to Earle for writing the orginal article and giving me the
    idea for this project.

    Allen Sandifer