One Of My Platys Is Dying. Help!

[TheBuuri]

Fish Symptoms (include full description including lesion, color, location, fish behavior):
Hello. One of the platys that I currently have in my tank is acting very strange and I am thinking that he might be dying. He has an odd bend in his side, and keeps floating as if he is dead. Whenever I remove the lid from my tank, he starts swimming erratically, sort of spinning as he swims. His eyes are sort of bulging out. I noticed this last night and thought that he was going to die, but he hasn't yet. Here is a picture of what he looks like:

 
Tank size: It is my roommate's tank, she said it is 8 gallons but I believe it is only five.
pH: unknown
ammonia: unknown
nitrite: unknown
nitrate: unknown 
kH: unknown 
gH: unknown 
tank temp: between 70 and 80 degrees (it is hard to read my thermometer)

Volume and Frequency of water changes: I change the water every few weeks to a month. I have to add water about every week because the water level gets low.

Chemical Additives or Media in your tank: Unknown

Tank inhabitants: Another platy, a red-tailed shark and a zebra snail

Recent additions to your tank (living or decoration): Not since I added these four about a month ago

Exposure to chemicals: Unknown

 

[RRaquariums]

Well your not going to like this but you have way to many fish in that tank even one platy is to much for a 5 gallon if that's what it is the shark really needs to be in something way bigger.
As for the sick platy I've had two of mine in the past do the same thing you described it was because the tank I had them in was to small and the build up of nitrates was deadly.
I don't think the sick one can be saved that's coming from personal experience my suggestion is euthanize him and then do a 90% water change on the tank after that I would look for a new tank that's at least 15-20 gallons if your going to try and keep the shark Petco has a dollar per gallon sale once in a while and you can get a 20 gallon long cheap.
If you can't get a new tank do a 50% water change once a week.

 

[TheBuuri]

Well your not going to like this but you have way to many fish in that tank even one platy is to much for a 5 gallon if that's what it is the shark really needs to be in something way bigger.
As for the sick platy I've had two of mine in the past do the same thing you described it was because the tank I had them in was to small and the build up of nitrates was deadly.
I don't think the sick one can be saved that's coming from personal experience my suggestion is euthanize him and then do a 90% water change on the tank after that I would look for a new tank that's at least 15-20 gallons if your going to try and keep the shark Petco has a dollar per gallon sale once in a while and you can get a 20 gallon long cheap.
If you can't get a new tank do a 50% water change once a week.

Like I said, it might be an 8 gallon tank which is still probably too small. My other two fish are completely fine. Where I am living currently only allows a fish tank up to 10 gallons, so I will only be able to get a tank that big. Thank you for your help. 

 

[RRaquariums]

10 gallons is still better also lots of water changes will help.
Sorry about the sick platy that always suck

 

[Ninjouzata]

Really sorry about your platy, agreed a 10g would be better, as well as picking up a liquid test kit.
Also I'd return the shark, their minimum tank size is a 55g.
 
Most do 25% WEEKLY water changes, so you may want to improve upon that too.
 
I'm not trying to be rude, it's just hard to say what the reason for it acting that way is without water parameters. I imagine RR is right though.

 

[TheBuuri]

When I was at the store getting the fish, the woman I talked to said that those three would be perfectly fine in the tank size I have them in. Everywhere else I've read said my shark would be fine as well. I guess that's my bad for believing the "professional" at the store and anyone online. Haha.. 

 I am going ASAP to get a bigger tank. But my shark seems perfectly find and content and I don't think I will have a problem with him.
 
Also, my platy has still not "passed on". He floats and still has the bend, but he is still breathing. Every time I go to move him he starts doing the spiraling-swimming thing. I honestly do not know what to do with him.

 

[Ninjouzata]

Unfortunately the pet stores are not the best to listen to, they want to sell you something after all
 
Glad you're going to pick up a bigger tank.
 
Your shark will become increasingly territorial as it ages, usually they stay on the bottom but I'm not sure if they'd end up going after the upper level fish with the small tank size.
 
HERE is some more information on them.
 
Sorry your platy still is not doing well..I wish I could help. The only thing I can think of is more frequent water changes. It'd help if you could get us the water parameters..until you can get a liquid test kit, some pet shops will test the water for you. Do make sure they're using liquid test though & ask them to give you the exact readings, not just "it's fine"

 

[attibones]

Definitely sounds like an issue with the nitrogen cycle. Have a read on cycling. You can find it in the beginner's section. Rehome the shark. His growth will be stunted and his lifespan drastically shortened. Complete daily 100% water changes, invest in a liquid based water test kit such as API freshwater master test kit. Do your best to make life comfortable for the platy until he does. Removing the ammonia from the water will help.

It is just a theory, but perhaps this guy suffers more than the others is because he was already a genetically weakened fish. PetsMart does not always get the healthiest of specimens. The ammonia or, at the very least, nitrate levels can cause the eye symptoms you are describing.

 

[TheBuuri]

Unfortunately the pet stores are not the best to listen to, they want to sell you something after all

 
Glad you're going to pick up a bigger tank.
 
Your shark will become increasingly territorial as it ages, usually they stay on the bottom but I'm not sure if they'd end up going after the upper level fish with the small tank size.
 
HERE is some more information on them.

 
Sorry your platy still is not doing well..I wish I could help. The only thing I can think of is more frequent water changes. It'd help if you could get us the water parameters..until you can get a liquid test kit, some pet shops will test the water for you. Do make sure they're using liquid test though & ask them to give you the exact readings, not just "it's fine"

My shark has been doing perfectly fine. He usually hangs out in a little gazebo looking thing I bought for the inside of their tank. I think he is going to be fine.
My fish is still acting strange today. I am taking a sample of their water to the pet store today and looking at prices for bigger tanks.
 
Thank you all again for the help.

 

[TheBuuri]

Hey everyone! I took the water to get checked. The ammonia levels were pretty high, so I am going to change out the water.
 
I looked more into what is wrong with my fish with a friend of mine, and we both think (judging on pictures and list of symptoms) that my fish is having Swim Bladder Disorder.  I am going to isolate him from the others and do the steps that is says to do to treat his disorder. If you have any advice, I would be glad for anymore help!