Help with female black lyretail molly!!

[ItchRinse]

hello all. i got 3 black lyretail mollies just over a week ago, and on sunday, one of the females died. She had lighter (whiteish) areas on her scales, and always just sat at the bottom. I'm thinking it was Ick or however you spell it. I've been meaning to do a 25% water change.... buuuut haven't yet ) And now my female-male ratio's 1:1 but i don't wanna get more fish and have them die on me, also.

Anyhow, the reason i'm posting is because the remaining female (Slit), her back end is either floating up, or her "nose end" is too heavy. She's also obviously pregnant, and i think its the front end that's too heavy because when she was beside the filter tube thing she kinda nosedived straight down. This doesn't seem all too normal.... So, i'm asking. what's wrong wit 'er? No white-ish patches on slit, either. The male seems fine, so far.

(also from Pantera (the dead female) she started getting sick like right after i put this bridge think into the tank. but the other fishes didn't get the same reaction. I took out the bridge thing tho, just in case. I stupidly let my mom clean it and it may have been in the tank with the long-ago goldfish that died of Ich... but it wasn't as fast acting as it was with Pantera..... )

Sorry for making this so long. but please, Help!

 

[canis_lupus]

i really don't know......i guess u could check the water parameters and do a water change and c if that helps.....my mollies act wierd before all the other fish like when i had a bit of nitrite inthe water. sometimes they just act strange even when things r fine. sorry i can't really help