DIY Yeast for 29g

After failing at a low tech tank I opted to try the DIY yeast. I did test mixes to see how long it took to get some bubbles and found that by using about 92 degree tap water it resulted in the quickest production of Co2 bubbles and lasted the longest. I've been using a drop checker with premixed water at a dKH of 4 and it's been registering green, and of course when CO2 starts to drop off the color starts to change. I've read that it supposed to last a month but it hasn't for me. I used 2 cups sugar, 1/2 tsp yeast and water. Yesterday I changed the yeast amount to 1 tsp and will see how that works. I had a ViaAqua in tank pump I had previously used in a SW nano tank so I'm using that for CO2 diffusing. I put a hole in the intake and slipped a hose barb in it and connected the CO2 line to it. The plants definitely look better and are growing faster.