I decided to go back to CO2 injection into my 72 tropical. However with the new DIY sump I added there was no place to add my old tall CO2 flame reactor (which I never posted but it was 100% effective/efficient). And I did not want another pump running all the damn time. So I used an Idea had seen before somewhere (proably here) and decided to use a gravity powered Vortex diffuser.
It simply will spin the water around inside a tube while the CO2 is injected up top. and the water swirls around inside and takes it as it can. the force of the bubble wanting to float keeps it from exiting the tube. To help the water spin I made the pipe come in flush with the tube.
To do this I just drilled a 1" hole straight in. Then took a 1 inch wooden rod and put it in. Heated it with a heat gun till the plastic could bend then pet it till the pipe could enter at that angle and blend nicely into the side. I glued it in place and then heated the pipe so that the hole side of the pipe is flush and not just the crest of the circle.
I left the bottom funnel unglued for maintenance. It sits in the bottom water disperser with it slittle factory flange. I figure if I want more spin on the water I can open it up and use a series of reducers to make a more tornatic shape and push the funnel up higher for quicker water spinning and to draw the CO2 bubble out. However I am not sure this is needed yet.
The hardest part was making it conform to my height restrictions. I had to cut all the fittings down so they all fit into each other nice and compact. I simply held them with needle nose pliers and used (as I do with all PVC) for old warn dull fine tools saw blade. I don't make it cut I mearly slowly slowly lower it into the pipe. the heat melts it and it tosses it away in strings. You have to let th blade cool every few moments by keeping it spinning but not cutting. You know when you can feel heat all over your hands.
Here you can see the heated and bent out pipe.
here you can see the pipe going in flush and the hole the CO2 will be entering.
and the stand thing that holds the lower funnel and such. I need to buy a one inch reducer for it I think.