The other day I was coming up with my new method of water changes and I needed something to clean up the tanks since I was just pulling out water and replacing it with the new system. I went to Petco and picked up one of their battery powered gravel vacuums and it burned out in 20 minutes and I wasn't about to exchange it so I used to have an air powered one a few years ago and it worked well for me. I couldn't find one locally and the shipping was more than the vac so I figured I would just make my own. Click here
this is what I use to have.
So here's what I did, I took some:
1/2" PVC the lengths will depend on you tanks and you can make different lengths for deeper and shallower tanks. You want to make sure you have a long piece on the back end of it or you can end up shooting water out the back all over the place if your air is set up too high.
1/2" PVC "T" coupling
1/2" PVC 45* coupling
1 piece of rigid airline
1 air control valve
2 or 3 zip ties
A toe section of knee highs or panty hose
A section of airline long enough to move around your tank(s)
An airpump the stronger the better
A drill to drill a hole for the rigid airline
Here is my version, the T coupling bottom has a short piece of PVC in it to connect the 45* coupling to it and hold the sock on.
Here is the front of it. I bent the rigid airline by heating it with a lighter. Make sure you don't collapse the airline when bending it, go slow and let it cool a bit as you are bending it, use pliers if you have to so you don't burn yourself. I matched up my drill bit to be just a 1/64" smaller than the airline and I drilled at an angle so the air bubbles would follow up the PVC better not sure it's necessary or not. I cut the tip to be at an angle so I have a better view of what's going in it as I have mostly sand tanks.
Here is the back end I angled it so I could keep the airline out of the way while I was using it.
Here it is working in a tank
For best results you would want to keep the T and 45* area where the sock is closer to the water surface.I find with sand it's best to work backwards dragging it on the surface of the sand, this stirs up the mulm and gets less sand in it because the mulm is lighter than the sand.
When I get a chance I will take some pictures of it taken apart so you can see how it all fits together for the people that aren't 100% sure. I didn't think about it when I was snapping pics.