Dying fish - unknown reason

[eaolson]

I'm fairly new to this hobby, having been at it less than a year. I'm losing fish, three in the past week, and I don't know why.

The tank as of a few weeks ago consisted of 6 zebra danios, 5 platys (3 adults, 2 younger fish), two ghost shrimp, and a snail that must have hitched a ride with some of the plants. This is a 29 gallon tank. Water quality is fairly good with undetectable ammonia and nitrite, and nitrates are 20-40 ppm. pH is about 7.8. It's been like that for about 5-6 months.

About two weeks ago, I got a dozen neon tetras. They didn't do so well, and within a week, the population was down to four, but has been stable since then. A week ago I added an air pump. Around that time, or possibly a little before, my platys have been dying at the rate of about one every two to three days. They seem to get lethargic, hovering near the surface of the water, then resting on the gravel, then they die. There's nothing visibly wrong with them. No spots or discoloration or lumps or anything else.

Because of the fact that this started not long after putting in the neons, I was worried about the dreaded neon tetra disease. But I'm not sure this would be this fast, and from what I've read online, bleaches out the color of the fish first.

This evening I noticed that the clear vinyl (Top Fin) air line wasn't clear where it was touching the water, but had turned white and opaque. I've removed it, but haven't been able to find anything online describing that. I don't know if it's just a coincidence or if there's something to it.

Any suggestions or ideas as to what might be killing my fish?

 

[Zagz]

Your fish hanging out at the surface seems to indicate water issues, whether it be quality or lack of oxygen. What kind of tests are you using? Liquid or strips? How often are you doing gravel vacs and water changes?

 

[Apocalypse_Gold]

Welcome to AA. We have a twelve-step program for...no...we don't.

What kind of test kit are you using? The test strips are notoriously inaccurate.

Neon Tetra Disease would be killing your neons first. It could be an internal infection. I like (to use) jungle's medicated food if I suspect bacterial infections. It could also be parasites or a fungus. Livebearers are prone to a particular "fungus" that shows no external signs. Try jungle fungus clear tank buddies and/or pimafix.

 

[Guest]

Agree with Zagz. Also, what tempature do you keep your tank at? I wouldn't worry about the airline, probably just some sort of buildup. Should be harmless.

Water quality is fairly good

Why do you say fairly?

I tend not to think it is neon tetra disease. It could be bacterial, parasites....The point that sticks out to me is that the problem started after you added new fish. How do you go about adding new fish, I mean the exact steps when you get home. Why I am asking this is for example, if you did not know and added all the water from the bag that you got the fish in, you may have introduced the problems that way. Just trying to narrow it down so we can come up with the best solution to help you.

And welcome to AA !!

 

[eaolson]

Your fish hanging out at the surface seems to indicate water issues, whether it be quality or lack of oxygen. What kind of tests are you using? Liquid or strips? How often are you doing gravel vacs and water changes?

Liquid for ammonia, Jungle 5-in-one for nitrite and nitrate. 5-7 gallon water change weekly, with gravel vacuuming.

They weren't gulping for air or anything, just hovering just under the water level back near the filter. I wonder if it was darker and the water flow less there. If it was a water quality issue, I don't understand why it would happen so suddenly, nothing other than what I listed has changed recently.

Agree with Zagz. Also, what tempature do you keep your tank at? I wouldn't worry about the airline, probably just some sort of buildup. Should be harmless.

Typically around 78. It's been creeping up to about 80-81 because of the hot weather we've been having here lately.

Why do you say fairly?

I was hoping to get the nitrates down a bit. I think I've read tetras don't like nitrates too much.

How do you go about adding new fish, I mean the exact steps when you get home. Why I am asking this is for example, if you did not know and added all the water from the bag that you got the fish in, you may have introduced the problems that way.

Usually hang the bag in the water for about an hour, adding a little of the tank water a few times. Tilt it sideways and let them swim out on their own. Yeah, I usually add all the water; only now do I read I'm not supposed to be doing that. Should I net them and dump them out instead?

Thanks for the advice.

 

[Guest]

Well there you have it! Yes, acclimate and then net the fish. You may have inntroduced parasites from the LFS water.

Also, the fish would not have been gulping for air. Hanging at the surface is an indication.

If the water gets to hot, run a fan across the top of it. This has helped me greatly. If it gets above 81 ,I would run an airstone or drop the water line IMO. Warmer water holds less oxygen

 

[Zagz]

You could also take a sample of water to your lfs for confirmation. Most lfs's will test water for free. Doing some extra pwc's will not hurt the fish and may help the situation.

 

[eaolson]

You could also take a sample of water to your lfs for confirmation. Most lfs's will test water for free. Doing some extra pwc's will not hurt the fish and may help the situation.

Confirmation of parasites, or confirmation of poor water quality or confirmation of low oxygen levels?

If it was low O2, I don't understand why it would affect one fish today, and not another fish until a few days later.