OverFlow Box, Instructions Options

[X-D-X]

Overflow Box (By SupernatePiranha)



This picture isn't to scale, but is merely to give you a vague idea. The inner boxes pipe needs to go closer to the bottom and the pipe in the bulkhead wont need to go as high either, just make sure it is above the bottom of the inner boxes pipe.







In order to use a wet/ dry filter you must be able to remove water from the tank and send it to the sump. This can be accomplished in two ways, the first is a drilled tank with a spillway, and the other is a hang on overflow box.

Construction:

The overflow can be made in a variety of ways to accomplish the same task, so I will first explain the theory behind the whole thing. There will be two compartments which will call the inner box and outer box. The inner box will have some sort of perforations on the top where you wish the water level of the tank to be, this box removes the water from the tank. The outer box is the box that sends the water to the sump. When constructing your box several things should be kept in mind, the first is that the inner box needs to be higher than the outer box, the second is that the stand pipe (described later) must never lose its siphon, the bulkhead has a pipe attached to it that is water tight and the top of the pipe must be higher than the bottom of the stand pipe in the inner box and finally the size of the boxes is determined by flow rate and tank size.

For the simple explanation of constructing the overflow I will use Rubbermaid containers, however the possible container options are endless, I merely choose a cheap and highly available one for simplification. You will need two of these to build the overflow.

1. In order to attach the the 2 container together you will need a piece of L-shaped aluminum bracket which can be bought at most hardware stores. You will cut 2 pieces of it slightly shorter than the width of your containers.

2. The next step is to cut about 1/4 - 1/3 of the height of one of the containers off the top and this will be your inner box.

3. Once this is done attach the L-shaped brackets to the top of both containers so that the protruding piece is on the top. I merely used aluminum pop rivets to do this which made it very easy. In most cases the L-shaped brackets will be wide enough to fit over the rim of your tank, but if they aren't you will need to buy some flat aluminum sheet and make a piece to widen them. Attach the two L-shaped brackets together using a screw and wing nut. On the outer box drill out and oval hole the diameter of the screw to allow a front to back adjustment of width. I suggest using two screws to attach them together with. On the inner box just drill two holes for the screws to come through.

4. After that you can connect the two containers together making sure that the bottom of the outer box is at least 3" lower than the bottom of the inner box.

5. Now to construct the stand pipe. Using the PVC piping and PVC cement we will create our stand pipe. All that is needed is a piece of pipe (I used 1 1/4", but you may need bigger tubing), a tee connector, and elbow and a cap as well as an adjustable air valve. Make the pipe for the inner box so that it is about 1.5" off of the bottom of the container. Then make the pipe for the outer box so that it is about 3/4" off the bottom of the container. By looking at the picture it is fairly self explanatory but you will need to cut small pieces of PVC pipe to go in between the elbow and the tee as well as in between the tee and the cap. Then you will use your PVC glue and put your pieces together and let them dry for 15 minutes. Now using your we need to drill a hole to install the air valve into. Drill it slightly smaller than the air valve threads. Now put a slight amount of aquarium glue on the threads of the valve and thread it in all the way.



Below is a picture of my stand pipe, I modified it slightly so I could use a foam pre-filter. The brass piece on top is the air valve.



6. Tapping the rear box for the bulkhead. Drill out a hole just big enough for the bulkhead to fit through on one side of your outer box. Install the bulkhead but don't over tighten the bulkhead because it may make a leak. Then glue a piece of pipe into the bulkhead.

7. Now you need to drill holes in your inner box for water to flow through. The size of the hole is up to you as long as you have enough water flow to keep up with your return pump. Make the holes where you want your tank water level to be at. Drill them the whole way around your inner box.

8. Next you need to attach your stand pipe into both of your containers. Put the pipe at the opposite end from your bulkhead. I merely used zip ties through the container wall then around the stand pipe to secure it into both boxes, however you may use any method you want just keep in mind that you want your stand pipe air tight! Now you want to cut a piece of PVC to glue into the bulkhead so that it will be 1/2 an inch above the bottom of the PVC pipe in the inner box. Make sure this part doesn't leak or you will lose your siphon.

Preparation for Use:

We need to let the aquarium glue dry for 48 hours before using the overflow. Once that is done you can put the box into the tank. Attach your hose for your outer box to drain into your sump with. In order to start your siphon you will have to pour water into both containers so that the stand pipe openings are submerged, this is very important! Then you will add water into your aquarium until enough water flows into your overflow. Next you attach and air hose to your air valve and open the valve, start sucking in on the hose until water is sucked from the inner box. Once this happens continue sucking until you get the air valve closed all the way. Now continue to pour more water in you tank which will go through your overflow boxes and fill your sump enough to keep your return pump submerged. Now you have created a continuous siphon, which will never lose siphon unless you take water out from the boxes.

This post has been edited by SupernatePiranha: Jan 20 2005, 03:31 PM

[wickedpuffers]

The pictures are gone!!

[glider]

not 4 me