Disappearing Fish!

[adelinamz]

Hi. I'm brand new to fishkeeping and have recently set up a 29-gal
tank (7 weeks ago). I had 8 zebra danios, 9 neon tetras, 2 dwarf
gouramis, 2 orange platies, and 3 small angels-- a white one, black
one, and a black/white spotted one.

I had two black angelfish die (both the original and the one I replaced it with) I replaced the 2nd black angel with another and since then I had a neon tetra die (it was over a year old, from a small tank my son had) and found a zebra danio wrapped around the filter intake tube. And now, it's been two days with no sign whatsoever of the white angel and four of the zebra danios! I've carefully searched and searched and there's no sign of
them. I think 2 neons are missing too! Granted, we do have a lot of plastic plants in there but I really have looked very carefully, moving the tank away from the wall, peeling off the backing and examining the back of the tank as well. The other fish (including the new black angel that we got on Wednesday) seem to be doing fine.

This is VERY discouraging . . . Any ideas? The angel certainly was too big to be eaten and I'd say the danios were too. The tank is kept covered except for the hole where the filter hangs and another small hole where a heater used to hang--now there are a couple of air tubes going through there. It seems to me that a fish would have to try awfully hard to jump out of there. Although the water level was pretty high after my last water-change. But I've searched the floor around the tank and there are no signs of fish. . . <sigh>

I've been doing 30% water changes once/week although after reading in an aquarium book that frequent large water changes are best, I did a 40% water change 3 days after my last 30% change. Come to think of it, I think the fish disappeared a day or so later. Is it possible to do too much water changing? :? amz

 

[Hypostomus]

What is the temperature of the tank?
How did you cycle it before putting fish in it?
What are your Ammonia and Nitrite readings? (If you don't have tests then take a water sample to your LFS).

Neon tetras and angelfish can be particularly picky about water conditions (the neons moreso than the angels), and the neons definately do not belong in a new tank. However, since you are having danios die I suspect your Ammonia is high. Danios are in a class I guess best called "Super Fish"-- they are extremely hard to kill.

There is no such thing as too many water changes unless you are doing fishless cycling. However, are you using a chlorine/chloramine remover before adding the water? Is it roughly the same temperature as the water in the tank?

Finally, are the remaining fish showing any signs of distress? These include gasping at the surface, discolorations and reddening of the gills, trouble swimming, etc.

 

[Matthi]

How are you removing water? I use a siphon hose which is big enough to do the streak thing if a neon got sucked up... may account for the dissapearances. If this is the case, having a bucket at the receiving end or a grille at the intake would be in order.

 

[adelinamz]

I'm removing the water using a Python (wow, those things are great---except I live in the desert and hate wasting water). We do it very carefully so I know we're not sucking up any fish.

The temperature of the water is around 78-80 degrees. I make sure the replacement water is about the same temp and I add stresscoat to the tank just before adding the replacement water (enough for the #gallons replaced).

I cycled the tank with 6 zebra danios in it (I put them in 24 hours after setting up the tank). They did fine and after about 2 weeks (I think) we added two angels, 2 dwarf gouramis, and 2 orange platies. The two angels are now gone but the other fish did fine. About a week later we added neons. We had a black angel die and a couple neons disappear, replaced the black angel and added a spotted angel and a couple of needle-nosed fish; the new black angel died too, one needle-nose fish disappeared and we found the body of the other. We replaced the black angel and added a couple more danios and more neons (slightly larger ones).

Before adding fish I take a sample of water to my lfs and have it tested. I didn't add any more fish after the danios until the water tested well (no ammonia/nitrites) and since adding the second batch of fish it's always tested well. And the remaining fish don't appear to be stressed at all as far as I can tell (no gulping for air---they swim around the tank serenely). So I assume the tank is now cycled?

How long do danios live? The one that died may have been the one from my son's original tank, so it would have been over a year old. But I can't be sure that's the one we found. The others have disappeared. I think it's odd that a total of 7 fish have disappeared without a trace since the last water change (one not-so-small--the angel).

I haven't yet cleaned the filter (aquaclear) nor vacuumed the gravel upon the advice of my lfs. They said to wait until the tank was at least 2 months old to do this in order to avoid disturbing the bacteria. But I wonder if I can vaccuum tonight and see if I can't find the fish.

As I said, the water level after the last water change was very high. And we did have the house cleaned the next day. It's possible I guess that the cleaning person might have swept up the fish without realizing it?? I wouldn't think that's likely though--I mean, we're talking 7 fish! The angels, by the way, aren't big enough to eat the fish . . . amz

 

[Menagerie]

[center:f99c24747f] Welcome to Aquarium Advice, adelinamz!! [/center:f99c24747f]
By all means vac the gravel! Don't rinse the filter, but take it apart and look for the fish.
Dried fish are pretty small and may have been picked up by the cleaner .

 

[adelinamz]

Thanks for the replies & welcome! I have an update. Last night we did a 40% water change and took out the large "colloseum ruins" that takes up half the tank. The fish seem to love swimming in and out and through this. Well, the top is hollowed out so fish can swim up there and be out of sight. Well, there was our poor white angel. It must have died while in the ruins and then floated to the top and got stuck there. <sigh> Still no sign of the 4 danios and 2 neons. I'll have to look inside the filter. I haven't vacuumed or cleaned the filter yet, as I said, upon the advice of my lfs. They say I shouldn't disturb the bacteria colonies yet as they haven't had a chance to build up sufficiently (the tank is 7-weeks old). Are you SURE it's ok to vac the gravel at this stage in the game? Will taking out the media and removing any fish I might find disturb the bacteria? I think at this point I will NOT replace the angel and hope that the remaining two (a black and a black/white spotted one) will do well and get along. So far all remaining fish appear to be healthy and happy. But now my "school" of danios is rather small (4). I've read that danios and neons feel more secure and do better in groups of at least 8. I have 4 zebra danios left, should I get 4 more zebra danios? I have 7 tetras left--should I get a couple more of those?? amz

 

[Melody]

leaving dead fish in there and I think you risk getting a fungal infection on everyone else, Id get rid of the dead fish, just dont replace the filter... rinse off in a bucket of fish water when you do a water change...
from growing up in CA. I too am a little conservitive with my water and I pour it on my plants outside, they seem to do really well with it,
Good luck!! you'll get it right, I'd avoid any more Angels for awhile...

 

[Atlarge]

Angels can pick on each other, I'd only keep 2. And they may munch on your neonsonce they grow some...