i could be troubled that something is inflicting the deaths of your tetras different than overstocking (it is, in spite of the undeniable fact that, a different danger). make certain you do a splash analyze, and verify out your water parameters, to make certain which you will no longer in simple terms kill any new fish you get. remedy the issue you have now till now getting greater fish. Theoretically, in case you had 8 tetras, you may desire to upload a trio of guppies or platies. Or 5 danios or harlequin rasboras. Or one male dwarf gourami, or one male OR lady betta.
Dail is easier to remember. If you feed twice a day, don't feed alot at one time. Feed what they can consume in afew mintues. Once or twice a week replace the regular food with somethinglike frozen brine shrimp or bloodworms for treats.
you know it really depends on how many fish you have. I mean even if you gave them just a little pinch right be fore bed time at least you would keep it consistent.I always feed my two tanks right at bedtime and then turn the lights off. It works because I know they have been fed when the lights are off and nothing to worry about.