mollies dead :-|

Question
hi, i recently bought 2 mollies, probly about 1 mth ago, and they were in a 5 gallon with 1 mini aquatic frog. They were doing great, but then yesterday one of them were dead, im pretty sure it was the female, and then last night the male was at the bottom a lot kind of laying on the rocks and then my mom found him dead thismorning, what could possibly be wrong? my frog is doing good and ive been changing maybe 30% of my water weekly with a syphoner or however u spell it. i also have 2 live plants in my aquarium and 2 plastic one, and i feed them regularily, i just hate not knowing whats wrong, because when the first 1 died i was planning on going out today to get a platie or another molly for a tankmate for the male but im afraid now to get more cuz i dont know whats wrong.

Thanx
Linsey

Answer
Hello Linsey. What kind of mollies are they? I'm pretty sure it might have been the water quality. From what you told me about the male, I think it might have been ammonia poisoning. I'd suggest that you get some ammonia chips that you can get from your local pet shop and put them in the filter cartridge. Hope this helps!