Haven't got a clue why my mollie fry/fish are dropping dead?

[Nyk0nn]

So I have 2 tanks that have Sailfin mollie fry/fish in them. One 75 gal densely planted tank with 15 mollie, 3 panda cory, 1 alb bn pleco and a 29 gal planted with 1 adult female and 7 one inch fry/fish in it with 6 Sterbai corys. Every time I have come home from work lately I am finding dead fish in my tanks. Most are 1 inch or bigger? My water parameters are stable and only difference is I have hard water but they were born in that. Why could they be dropping off like files? My wife tends to overfeed a tab so they are not starving? At one time I had 30 fry in the 75 gal but now I'm down to about 15... I'm not having any issues with any of my other tanks/fish?? Anyone have an insight? Is it just natural selection or growth/ development issues? My wife keeps asking me and I have no ideas.

Thanks as always!
B

 

[fishorama]

Have you tested your water lately? How often do you change water & how much? How long have these tanks be set up? I remember you have a few...

I have not kept mollies but at 1 inch the "fry" are more juveniles, they've made it past the "new fry danger zone". How do the adults look & act? Any aggression there? Any new tank additions plants or animals or even decor or filters?

Maybe your wife's overfeeding is at least part of the problem. A small amount of flakes once or at most twice/day is plenty. Fish really only need a couple bites of food/day...but they often beg whether they're hungry or not. If she feeds every time she walks by...well, it could be a lot!

There might be a seasonal water differences as we head into spring. Could your water co. or well water have changed? Mine did in MA & at a different times, here in CA too. We lived in north DE & had pretty hard water (mollies like it) but spring melt might dilute that. I see you live in PA, maybe an issue?

 

[Nyk0nn]

Yes, other than hard water everything is normal. I add RO water from the lfs as well to soften it up some. My other 2 tanks have no issues? My other 75 gal community has a few mollies in it and there isn't any issues in that tank. Same with my 20 gal neon. Other fish in the previous mentioned tanks are doing fine, shrimp and snails are good as well its just the mollies?? I haven't added anything new and thoroughly wash/rinse anything that goes in. She doesn't feed them like that its just she has a heavy hand if you will with the pinches of food, lol. No aggression that I can see. There is only one female adult in the 29 gal and it has 7 juveniles and five new fry but as of yesterday I'm down to 4 juv and 3 maybe 4 fry? The 75 gal has only juveniles in it and I just pulled another out yesterday?