This is a small simple and cheap DIY 12 volt / Solar operating Air / Aerator system for pond (but can be used for other stuffs as well that you people can find uses for).

The idea came to me when I really needed a simple solution where I would require little power to aerate my pond because of the water turning green due to being still and lack of oxygen. I tried to go for commercially available ones but they were nowhere to be found and if found would be too expensive and too big for my pond.

So after some research and looking at aquarium system the idea came so that I could get the parts myself and assemble them in order to make a cheaper and more efficient system which I will show to get the parts and build them.

Step 1: Gathering of All the Parts

Here are the parts required for the system and I assume that you have all the parts to assemble the system such as screwdriver, knife, solder, soldering gun etc.....

- Air pump operating on 12v and lower (I choose two pumps as I wanted air to come in another part of the pond as well)

- Soft Oxygen Air Hose (to connect to pump and airstone that will bring the air into the water. Size 4 * 6mm )

- Air Stone (a stone to diffuse the oxygen into the water)

- Weatherproof Pump and electrical housing / enclosure (I choose to have a Plexo box rated IP44 where I could easily house everything)

- Red and Black Wires to connect the pump to power supply.

- Heat Shrink tubing to put on electrical joints to prevent short circuit.

- Two way terminal block to connect the pumps to power.

After parts have been gathered, planning upon how the system will be built will be drawn on paper.

Step 2: Designing the Plan on Paper to Know How to Proceed With the Assembling.

The fastest way is to use pencil pen and paper. Here is the plan below that I drew before doing the real thing. The advantage of doing this is that we can go several times over and find any missing steps and correct them now instead of in the process of having to go back and modify (if possible) that might end up in doing everything again and even the need of buying broken parts.

First I made the planning of where I wanted to place the air stones in my pond so that there would be enough movement in the water as well as to add a bit of decor in it.

Afterwards I make the planning for the Air system of how everything will be arranged and connected together.

Step 3: Preparing and Assembling the Parts

The first thing would be to solder the wiring to the pumps as after this process many parts would be fused together thus less cluttering the place / area of work. Prepare the wires by cutting the length that would be required to attach to the pump and the electrical socket, then move the wires apart, red and black apart just to be enough to be able to reach the polarities / terminals ( + and - ) on the pump and then peel a small bit of the plastic on the wires to expose the copper part.

Then cut the shrink tube just enough to cover the soldered part and up to the wire where it isn't bared. Then insert the shrink tube on the stripped wire further onto the plastic as when soldering we do not want that to get in the way and just shrink in place.

Before attaching the wires to the pumps and solder them, any existing wiring and solder needs to be removed by desoldering and cleaned up. After the cleaning process the new wires can be attached to the pump, for security reasons and standard, I've put + and - signs onto the pump terminals and attached the Red wire to the + terminal and Black wire to the - terminal. Now prepare the solder and heat up the soldering iron, by the time it is being heated, double check the wiring if has been properly attached and in the right setting and don't forget to put the shrink tubing onto the wire. Now begin to solder the wires to the air pump and finally slide the shrink tube over the solder and the plastic part of the wire and heat the shrink around until it shrinks and make a tight seal. A good and fast way to shrink the tube would be to use the iron tip onto the heat shrink tube and seal it.

Since everything is going to be stored into a tight enclosure, it is much better to connect the pump and the wires together outside as it will be much easier. Also once everything has been connected the parts can just be put inside the box easily and close it.

Now to the part of assembling outside the box. First put the two pumps side to side and then twist the two red wires from both pumps together and then do the same with the black wires. Then take the twisted red wire and insert it into the 2-way terminal on one side and then insert the twisted black wire into the other side and screw in place to secure the wire, use the picture as reference. NOTE: any wire can be inserted into either side, it's just that the terminal doesn't have any polarity meaning no positive or negative, what I did was to mark the positive and negative sign on the terminal so that I don't get confused and put the wrong wires into the wrong holes that might damage the components or even cause injury. Once everything has been connected, add power to see if everything is working as it should and if something is, now would be the time to fix it.

Step 4: Placing All the Components Into the Box / Enclosure.

Before even placing all the components into the box, ensure that the final resting position meaning where the box / enclosure will be permanently mounted / positioned to know the power wiring entering the box will be and where the air hose will be attached. For my case which is an electrical outdoor plexo box, I can cut the bushings in all 4 sides so I need to make sure that the one I cut will be the ones that I will use and in the correct position as well. In step 2 there is a planning and because of that I know where to place the box and where to cut exactly.

Based on where the air stones will be placed in the pond, the distance between the air pump to the area where the stone will be placed, measure that distance in depth and length then cut the air hose to the required length for each pump. Once the areas where the electrical wire and the air hose will go have been located, I mark them (In my case I mark the Bushings). Then the size that the air hose will use, I only cut the size a bit smaller so that the tube needs to be pushed in tight as we want it to be waterproof and the same goes for the power cable.

Once the holes have been made, the air hoses are the first to be inserted as these will require much force to get into. Once completed, the hoses are pulled in further in order to ease the connection to the pumps. Now that the air hose have been connected it is up to you if you want to glue the hose to the pump outlet or tie a zip tie over the air hose onto the pump outlet to prevent it from detaching. In my case I just snapped mine onto the pump which seemed tight enough to be removed by it own. Once these have been connected it is time to put everything together. For me since the box is tight, I need to squeeze everything inside, thus the extra air hose that was pulled in to ease the connection now needs to be pulled out slowly and gently while holding and pushing the pump inlet slightly inverted so that it fits inside the bushing until the pumps are properly housed.