Sick Fish! Not Sure Of Cause

[Purdysboy]

Hello,
I'm new to the forum. I'm having some problems with my fish. I have a 20 gallon tank that has been up and running since this April. It houses 4 Tiger Barbs, 2 Long Skirt Tetras, 3 Neon Tetras, 2 Mollies, 3 adult Platies and 8 plus Platy fry. Several of my fish have been getting sick and dying quickly lately. Symptoms are not eating, losing weight fast and then they just seem lose control of their fins and drift around the tank before dying. I can't understand what's happening. I haven't got any new fish lately, I keep the tank very clean and do partial water changes at least once a week. Please help me figure out what going on, another Platy just started showing the symptoms. Thanks, Joe

 

[Blitz]

Hello, welcome to the forum.

How old is the tank? When you first got it, did you cycle it? Have you tested your water?
I must say, that tank is overstocked and those fish aren't supposed to be kept like that. It could be a sign of stress (hmmm, could it be?) or they're feeling overcrowded. I highly advise you to upgrade to a 55gallon. The tiger barbs should be kept in odd numbers. For, they can become very aggressive towards each other and nip each other's fins. If there's an odd number, they won't pair up and begin to nip on another. The skirt tetras also need to be in groups of AT LEAST 5, same with the neon tetras. If you get the 55 gallon, let the future platy fry be, and the new gerneration of platys won't start and make your tank overcrowded. So, I HIGHLY ADVISE you to upgrade to at least a 55 gallon.
-5 tiger barbs
-at least 5 skirt tetras
-at least 5 neons
It'll be better if you have a bigger tank. Two reasons, 1) will be a lot better for the fish, especially barbs and tetras. 2) might be a little easier to take care of it.
I do believe some fish keepers do a 10-15% water change everday. That's the way I learned it: Do a 15% water change everyday and never overstock!

-Blitz