And we have gone through this once before not that long ago.

I have a 36gl with Platies and neons. ALL of my platies are sick. They all have clamped fins, puffy gils (well one does) and one had shredded fins.
Now we JUST had this issue and we thought we had it all clear. Everyone was healthy swimming, eating, and being crazy and frisky as always.
I come back from vacation yesterday(my boyfriend took care of the fish while i was gone. they are his also) To them being sick again, and worse! he lost one over the weekend, and we just lost another one this morning :-( We've has these fish for almost a year. Nothing like this has ever happened before until last month. We have always done weekly water changes. API results the two weeks wernt HATEFUL but not perfect either so we did water changes and treated the tank with medicine (Marycen?? i believe) That is what cured them before. Now they are much worse and I dont know what else to do.

ANy advice ? I dont have updated test reults.... and we havent done a water change in maybe two weeks (which has happened before but never anything bad came from it).

:-(

we have 5 platies left. the neons dont seem to be affected.

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Test the water and see what the results are, and do a water change immediately, and go from there. Maybe add some aquarium salt to the tank as well

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"Being ignorant is not so much a Shame, as being unwilling to learn".-- Benjamin Franklin

Should i try salt first before treating the tank with more meds?

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Yea it cant hurt. Follow the directions which are 1tsp per 5 gal i believe. Unless you have scaleless fish (like plecos etc) then half it.

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"Being ignorant is not so much a Shame, as being unwilling to learn".-- Benjamin Franklin

ok. We plan on doing a water change and vacuming tonight, then Ill start on the salt. I should raise the temp a few degrees too, right? I think it sits at about 78-ish

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I cant believe we lost two of our babies in 2 days. Its been forEVER since we lost a fish. And we've had our platies almost a year. so sad

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I would do a couple water changes in 40-50% range a few days in a row. I don't think your fish are sick. Sounds like how fish act with prolonged periods in high nitrates. A good weekly water change schedule with changes in the 35-50% range, would do your tank wonders.

Reinforcing Ben's advice - what was your water changing schedule before this? Were you dechlorinating the water you add to the tank?

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Officially fishless until after the move....tune in later for details!

I agree. Some people call it 'old tank syndrome' because levels can slowly get out of whack when you have been doing the same thing for a long time and often get a bit lazy too. Also maybe your stocking level has gotten high because of fish growing and having babies, or they have been overfed while you were away. I'd go with water changes rather than meds unless you know what's causing it because meds are often strong enough to finish off weak fish.