Today, I set up a diy yeast co2 system and I need a diffuser. Right now, I just have a chopstick stuck in the end of the hose. I do not want an entire reactor, just a diffuser, and I would like for it to be cheap if possible.
Cheaper, it's th cheapest thing I could thing of.
With and airstone most of the air goes straight up and goes into the air instead of the water.
You said it was a diy system.
Make a diy deffuser, try you tube.
I'm sure there are some awesome cheap ideas.