Last of the old guppies died yesterday...

Yesterday, the last of the first batch of old guppies died... was already quite sick the day before with redder than normal gills, which from the net seems to be caused by high ammonia levels... and the main cause of that seems to be over-feeding... will try to control that... also...my guppy fry also died... sigh... whats left of my first batch of fish is now the 3 neon tetras...hopefully with the 6 new tetras, they have a higher chance of survival...