just read awwww i'm sooo sorry for your losses i know how you feel. I went away to manchester for a weekend i came back monday afternoon to a cloudy tank, filter hardly working (never found the cause) Pepper cory dead upside down, albino cory was half dead and tried to save him but died in the night. 1 female guppy was dead underneath a plant and the tank was very cloudy due to the filter not working properly. I was gutted about my cories as they were my first cories i had ever bought, left me with 1 bronze cory which took ages to socialise with the new cories that i bought a month after.
I don't like other people looking after my animals, with my fish i usually use feeding blocks that you drop into the tank and slowly dissolve and they also keep the water fresh and i use a timer to operate the lights. My sister looks after my hamsters but tends to fill there dishies too high of food and they end up wasting it all over their living quarters.
So i know how you feel when your tank goes belly up.