1 white cloud and 1 male guppy died...

Sigh... 1 male guppy died in the morning and 1 white clould died when i came back after work... was it because i fed too much? I definitely set the feeder to too high a value... what works in 1 tank may not work for another one... a lot of food settled at the bottom of the tank...had to suck off the extra food on the sand by using a small pipe... then did a 40% water change...Then... did the earlier Male guppy died because I fed too little? Anyway decided to add a piece of card to the automatic feeder so that the amount of food per feeding is reduced by about 75%... hopefully this time round it works...