Xtreme_B

I bought 4 small Angelfish(about 2") 3 weeks ago.Three of them died within 2 weeks.I bought 3 more, one of them the same size and 2 medium Angels and they are getting along great.Last night I did a 25% water change and siphoned the gravel in the tank which is a 55g.And this morning I found the last one from the first batch dead in the tank.The odd thing about is that the water smelled like rotten eggs when it's in the bucket.The tank itself doesn't smell and neither does the water of my 29g tank.The water comes from the same fauced as the water that I put in my 29g and it's all filtered water.I have no Idea what's going on here.Any help is greatly appreciated.

Thanks,Susanne

jsalemi

Sounds like you may have had a pocket of gas (usually nitrite) built up in the gravel which you released when you were siphoning it. As I understand it, those can build up from overfeeding, where the extra food sits in the substrate and rots away. You can prevent it in the future by cutting back on the amount you're feeding your angels (remember, a fish's stomach is only about as big as its eye), and getting some bottom feeders ( a school of corys or a small pleco are good for a 29g) to eat the food that hits the bottom before it can turn nasty.

Is the tank cycled? What's the water chemistry like?

Isabella

Jsalemi makes very good points. I'd also like to know your water parameters: Ammonia, Nitrite, Nitrate, and pH.

How often do you perform your water changes and how large are they each time? Do you have any other fish (besides the Angels) in the tank? If so, what fish and how many?

When you bought your Angels, did you acclimatize them? If so, how?

When you do your water changes, it's always best to deep-vacuum the gravel with each water change. If you don't deep-vacuum it with each water change, at least stir the gravel once or twice a week, so that - as Jsalemi has pointed out - no dangerous gas pockets form in your gravel.

P.S. Oftentimes, you buy fish that are already sick, only the disease comes out after a while. This is why many people quarantine newly-bought fish for a month or so, before introducing them to the main tank.

Kevin

you could get a couple of snails, they keep the gravel stirred up really well...you could also get some bottom feeders to eat the extra food that falls to the gravel

sirdarksol

I second Isabella's question, and want to note that there are worse things that can build up in unsiphoned gravel than nitrite.
Pockets of non-oxygenated water can build up, allowing anaerobic bacteria to grow. The waste products of anaerobic bacteria are some of the most toxic substances on the planet. Botulism toxin, for example, is created by anaerobic bacteria.
My second question is "how strong is the rotten eggs smell?"
If it's a mild smell, it's probably just rotting food/waste buildup, and could very well be nitrites that killed the fish.
If, however, it's a very strong smell, it's very likely something worse, and your gravel needs a thorough vacuuming (pull any remaining fish, if there are any, out first).
As Kevin said, you might want to think about getting snails. Malaysian snails are great burrowers, and will eat some of the leftover food in the gravel, as well as aerate the gravel. No help for the fish already deceased, but aid for the future

Or, this might have nothing to do with gravel. Best to cover all bases, though.

Xtreme_B

I did a 25% water change and I always siphon the gravel really deep down every weekend.I did feed the fish once a day just a pich of flakes til Capekate told me that I might not feed them enough.So I feed them twice a day now a little more then a pinch.When I siphoned I didn't get hardly any food or dirt out,so I guess they eat most of it.I also have 2 Cory's in there.My water levels were all at 0ppm.I did cycle the tank for 6 weeks til it was completely done.Can all of you please let me know how much you feed your fish and how often?

Xtreme_B

Well the smell was really strong and I did siphon the gravel really good i thought atleast.Now the gravel in this tank is alot smaller then the one I have in my 29g.I have a picture up if anyone wants to take a look.It's like really tiny gravel.

sirdarksol

Alright, I'm guessing you had just missed a pocket, if the smell was really strong.

As far as how much to feed the fish, make sure each fish gets at least one flake at least once a day. I feed my fish twice a day (increases the chances that each fish gets at least one flake). A fish's stomach is about the size of its eye, and, being cold-blooded, fish don't need as much food, comparatively, as a human. Further, most fish can go for days without food and not suffer any ill effects. There are exceptions to this rule, though. Otos, for example, need to eat almost constantly. Thankfully, the majority of the exceptions eat algae or little bits from the gravel.

Xtreme_B

I think my fish get atleast 1 flake if not more.Do you think I should siphon the garvel again or wait til the weekend when I usually do it?

Kevin

i would wait...and you might not want to "siphon" every week, maybe "siphon every 2 weeks, but stir it up the week in-between

Isabella

To answer your question about feeding: I feed my fish 2 - 3 times a day, very small amounts.

Since your water parameters are perfect (with 0 Ammonia, 0 Nitrite, and 0 Nitrate), and since you said you deep-vacuum your gravel every weekend, then I am baffled at what might have caused the rotten smell as well as what caused your Angel to die. Once again: Do you have any other fish in the tank besides the 2 Cories and now 1 Angel (right?) ?

Xtreme_B

3 Angels and 2 Cory's.The only thing that I can think of is.When my tank finished it's cycle 3 weeks ago,I did a 50% water change but didn't siphon the gravel.Cause I was told not to.Then I bought the first 4 Angels and the 2 Cory's.A week after that I did a 10% water change and siphoned the gravel and now the 25% water change and siphoned the gravel and both times it had the rotten egg smell.Maybe I should have siphoned when I did the 50% cause I cycled with lots of flake food and then switched to a raw shrimp.Maybe there was still too much stuff in the gravel?When the first 3 Angels died I went and got 3 more,and now the last 1 of the first 4 died and I'm back to 3.....lol I hope I'm not to confusing.


Susanne

sirdarksol

I would vacuum every week. At this point, you might as well wait until the weekend, in my opinion. I'm with Isabella that this seems odd, but I can't think of any possible answers other than dumb luck that you somehow missed a pocket for several weeks in a row.

Isabella

I agree with Sirdarksol too. I mean, what else could smell so bad in a very clean and well-maintained tank?

Jim

wait, maybe I missed it somewhere, but what kind of filter do you have? is it an undergravel? I just wondered, because those are nitorious for having any number of nasty things build up under them. I had nightmares with mine, because every time I siphoned the gravel too deep, something from under there would kill off half my fish.

fishgirl

If you use an under gravel filter you should not deep vacuum it, you will suck out all the good bacteria. You should do ONLY light vacuuming of the gravel. I use BOTH under gravel and over the back filters and do light vacuuming when I do my water changes.

The only time I have had any problems with my tanks is when I covered the tank for 3 days to kill off the algea build-up after I was having my husband feed the fish and he was over feeding( Now he knows better)

sirdarksol

I disagree that you should not deep vacuum with a UGF. Failure to do so increases the chances that gunk will build up in the UGF and create non-oxygenated pockets.
I deep-vacuum every time I do a water change, and have never had any problem. The bacteria are small enough to wedge themselves into the pores in the rocks. Vacuuming is similar to swishing a used biomedia sponge in a bucket of water. It gets rid of th gunk without removing too much of the bacteria.

Xtreme_B

I don't have a undergravel filter,I have a Whisper Power filter which is the double filter 30-60g.The 3 Angels that I have right now are doing well,so hopefully they survive when i clean the tank tomorrow.