I liked the different recipes on http://www.doylesdartden.com/fruitfly.html so I decided to make slight adjustments to one to make it a little more cost effective.
Here is a quote from The Power Mix recipe by Chris Miller.
"1/3 cup Brewers Yeast (the key ingredient)". So how important is it? I couldn't find any at Albertsons or Ralfhs, so I guess I will try Trader Joes.
This one recipe caught my attention because it was noted that there was an increase in production. I changed a few items to suit what I had around the house. I ended up using mash potato flakes, 2 bananas, powdered sugar, kaytee baby bird formula (had extra lying around and thought it couldn't hurt), baker's active yeast (I wonder if I used too much), methyl paraben, and some water. Sounds ok?
The picture below is an example of what it looks like now. It is still cooling down. I will use a coffee filter with rubber band on top. I am getting my fruit flies tomarrow and hoped to use it. I still need to buy some screen or something for them to create more surface area.





Thanks for the suggestion.