You can look on other posts that have similar problems for now. I am not an expert, and do not take my word for it, but you can give them both a Freshwater Dip. Pete has a huge tutorial on this, but do not be intimidated. It is a real simple concept. Get the ponies into Fresh Water. That’s it. Of course you ave to monitor them, and you cannot leave them in there for to long. Water Temps and Water Quality are important in a Fresh Water Dip. Put Something for them to hitch to and wait. I was told if they can go 8 min you are doing great, but you can’t just stop at 8 min. Let them go a little further or until they are really thrashing or look uncomfortable. If this happens before 8 mins. there is a problem. The less stress the better off they are, of course. But all of those extra things, may foul your water without proper filtration. I would yield to Pete’s postings, but like I said, don’t be intimidated. Chances are you will need to do this sometime if you are going stick with Saltwater Aquariums. I hope this helps, this forum has 100’s of posts, Pete has offered his support to us all, and I feel as a “Newbie” myself that we all should try and help whenever we can. You can do it, those little guys do count on you for most all of what they have, except their natural inclination to do whatever they are doing. That might help in a search for what is going on. If you cannot find it here, and cannot wait for an answer, use y he internet and research. Be sure you can find at the very least 2 sources to verify what ponies are displaying. Since you have had them this long, you also might have been able to deduct that each one has a certain “Character” about them. You know like are they feisty, strong, resilient, shy you know stuff like that. Have they been through much with your tank without question. Melafix and that kind of stuff, is a foreign substance that might initially have had an effect on them, so you might want to wait out the treatment. Just remember, that over time it does have an effect on your whole biological and mechanical filtration and depending on what brand, I cannot guarantee it won’t somehow foul your water. You can do it, kid!!!!!!! Got my fingers crossed……..