Silver Mollies

Question
My sister and I have 2 silver mollies and they started out looking like all the other silver mollies.  My sister's been keeping different mollies for over 2 years and she's a bit stumped as she's never seen this.  The two mollies in question (one in a 20 gallon, the other in a 10) are atleast 6 months old. Recently though, their dorsal fins became longer so it doesn't stand up unless they're actively swimming and they're turning a spotty brown.  She doesn't know if this is bad for them or not, or if there is something that will be wrong later on. She loves the fishes to death so she just wanted to be sure.
Also, I wanted to ask for advice on popeye. Another silver molly of ours got (I think) popeye about a week and a half ago.  I've been using the Maracyn brand of medicine and put in the aquarium salt but it still has the popeye.  The tank has been up for atleast 6 months, and I did a water change a few days ago.  I was wondering if I am doing something wrong or if it is even popeye.  Only one eye is protruding and the fish seems to be okay, if only a little lethargic.  We've never seen a fish with popeye but to us it sounded similar. Thank you for any advice in advance.

Answer
Sounds like you have a sailfin mollie. They are very pretty and have huge dorsal fins, unless there is something else I am missing there should be nothing wrong there.
If it is indeed popeye, the best thing you can do for him is lots of small water changes. And by lots I mean at least every other day. Fresh water always does the trick. Do a 25% every other day and keep him stress free.
There's no such thing as too many water changes, but there can be too little!