You get the grand prize! As I said, none of my old tricks work well in shallow water. So I got some 1/2" CPVC pipe and end caps and made some DIY air “stones”. They will cost me about $.75 each.
The CVPC stuff is much smaller than regular PVC pipe and fittings, but Im sure the regular stuff would work just fine.
These look to me like they will work great with much less chance of clogging up or growing bad stuff than normal air stones - I hope.
2ea end caps = $.64 (you can probably buy them in 10 packs for less)
1ea 1/4" air hose barb ell = $.10
1" of pipe = $.03 ( a 5ft piece costs $1.96. That will make 60 “stones”)
You dont need any glue. Just press the parts together. Here are some pics.
I drilled a 3/16" hole in the cap, then ream it out carefully until the barb fitting almost slips in. You want the hole too small, but not toooooo small.
I wrapped the fitting with some teflon tape, but I dont think thats necessary. No big deal if it leaks a bit - thats just more bubbles.
I use my vice to press the fitting in place. If the hole is sized properly, the barb on the fitting will snap in and hold it pretty tight.
All done.
Next, I drilled some 1mm holes in the second end cap. Thats the smallest drill bit I had handy. I tried 4 holes, 6 holes and 8 holes. More holes gives more water movement, but takes more air. I have a 900 L/Min pump and it looks like it could handle at least 6 of these with 6 holes each.
You can even make a curtain wall type or probably a circle or square if you wanted. I tried an 9" long one and it worked well, but it has to sit pretty level or the bubbles are not evenly distributed. It also takes a lot more air with all those holes. Im going to stick with the small ones. Probably 6ea in the tote - Two at each end and two in the middle.
This is two of them in a 5 gal bucket running with the air turned down. Really boils the water well.
I ordered a couple of WaterFarm plumbing kits to do the drip since my tricks were not working. Ill test one out as soon as it gets here. They are only about $11ea on Amazon.