Step 1: Supplies
1) at least one 10mm high brightness LED's (you can have as many as you want)(radioshack has the ones)
2) Some small gauge wire such as 18-22 gauge.
3) Epoxy or similar glue
5) 6 volt lantern battery.
1) Wire connectors
3) Soldering Iron
Step 2: Main Body Modifications
First you will need to drill a hole, about an inch below the caps bottom end, large enough for your wires to fit through (you can drill two small ones too) next you will want to pull enough wire to work with, out of the tube you will want at least 4 inches to work with.
Step 3: Wiring the LEDS
First cut the insulation just where it comes out of the top of the tube, you then want to slide it about 1/4 inch and expose the bare wire(don't completely remove it!) do the same with the other wire. Now it should look like the picture. Next use a small pointed object to make a small hole in the bare section of wire, now slide one end of the LED into the hole and fold the lead around the bare wire, and then twist the power wire to close the hole around the LED now you can use either solder or superglue to secure the LED lead in place. Now repeat this step with the other side of the LED. After that you are ready to cut a new strip into the wire for your next LED jus follow this step and you can finish the LEDs, you want to put them about an inch apart.
Step 4: Inserting LEDs Into the Tube
Now that your finished with the LED wiring you can snipp off the excess wire, then you want to take the slack out of the wire so it pulls the LEDs into the pipe now arrange them in a circle around the inside of the tube and try to aim them at the nozzle. Once done you can glue them to the side walls of the pipe but since I only used one I will let it hang free as seen.
Also i know it sounds crazy but the wires need no insulation between the terminals!!! That is because normal water does not conduct electricity as show in the second picture it requires salt water to conduct electricity efficiently enough to short it.
Step 5: Wires
Now mix some epoxy and thouroughly coat the wires on the outside of the holes to seal them in as pictured. (if you use superglue the water pressure will force it out)
This is optional but you can put a conector on the wires for the battery or you can leave them bare and wrap it around the battery terminals.
Step 6: Wrap Up
Finally put the nozzle cap on and test the lights you should get a bright concentrated dot out the end as seen. Be sure you DO NOT LEAVE THEM ON WHILE DRY!!!! The lights get very hot when being driven at this voltage but when the water is running you have your own water cooling system so you can use them till the battery goes dead!!! The light looks purple in the picture but it is actually a 5mm ultraviolet LED, i would not recommend them as they are not as bright as the bigger 10mm bulbs such as the blue ones, if you can find big ultraviolet ones then you can use them. The light wasn't as bright as I thought so it only illuminated the beam when it got an air bubble in it or it started to break up, but brighter lights would solve this.
Step 7: Fin.
So now you have a functioning illuminated Laminar Flow Water Jet. This be my last laminar flow instructable for a while as I have to make a cutter and possibly multicolored- fading LEDs. I am planning on using an arduino to controll everything, I am open to any suggestions, but until next time happy instructable-ing.