I have a 55 gallon tank with Angelfish, Cardinal Tetra, Cory Cats and an Emperor Pleco. The tank has been up and running for almost two years now, the water tests fine and I do a 50% water change weekly. I have done a couple of different stocking schemes with it but I am very happy with my current setup. The tank has smooth gravel, lots of driftwood and is fairly heavily planted. I have never had issues with fish dying and am stumped by this one. I have had 6 leopard cory cats for about a month now. Over the past few weeks I have slowly been picking them out of tank, and today I removed the last fallen soldier. They were very active for the first week or so, as expected, and then they just started laying around doing nothing. I make sure food reaches the bottom for them and they seem to be eating. What is totally blowing my mind is the Angelfish and Cardinal Tetra are completely fine and I would think they would have health problems long before the cories, but I have not lost any of them. I need to figure this out because the cories complete the biotype and I really like the activity of healthy cory cats. Also, my plan now is to do Sterbai and they are running about $10 a fish in my area.
Cory Cats Dying?
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This is not that uncommon, but there is always a reason so let us work to help you find it.
Can you test and post results for ammonia, nitrite and nitrate?
Live plants? And some wood (real or artificial) on the substrate?
Temperature?
Water hardness for tap, you can find this out from your water supply people; I agree it is likely soft/medium hard, but let's check so we can eliminate or deal with it.
Which water conditioner?
What food reached the bottom, just flakes or actual sinking foods?
How large is the pleco?
Byron.
Can you test and post results for ammonia, nitrite and nitrate?
Live plants? And some wood (real or artificial) on the substrate?
Temperature?
Water hardness for tap, you can find this out from your water supply people; I agree it is likely soft/medium hard, but let's check so we can eliminate or deal with it.
Which water conditioner?
What food reached the bottom, just flakes or actual sinking foods?
How large is the pleco?
Byron.
6.8 pH
6 dH
0, 0 , >10
Amazon Swords, Anubias, Valisenria, driftwood, average aquarium gravel
I use Prime with water changes and Flourish comprehensive weekly. My pleco is about 6 inches (largest fish in the tank), could he be messing with the cories? I would prefer to have a large school of cories rather than one pleco. I use mostly flakes, but I feed sinking pellets every other day.
6 dH
0, 0 , >10
Amazon Swords, Anubias, Valisenria, driftwood, average aquarium gravel
I use Prime with water changes and Flourish comprehensive weekly. My pleco is about 6 inches (largest fish in the tank), could he be messing with the cories? I would prefer to have a large school of cories rather than one pleco. I use mostly flakes, but I feed sinking pellets every other day.
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This is a bit warm for the cory's who would much prefer 75 degree's to perhaps 77 degrees F.
Those I have kept at temp's much above 75 degree's F, seldom lasted longer than a few month's to a year with exception of Sterbai corydora's.
I believe they would benefit from shrimp pellet's, blood worms,chopped earth worm's,spirulina pellet's,bit's of krill,all offered after light's off for the evening.
Much bacterial activity takes place on substrate and in my view,this could result in low oxygen level at substrate where these fishes spend their majority but this is only my feeling.
Could also be that bacterial activity (decomposing organic's) make these little fish more susceptible to bacterial infection's but It is speculation on my part.
Creating some movement along the substrate by use of powerhead or positioning spray bar differently may help.
I personally quit keeping these cory's (False Julii ?) for I too was having problem's with them dying despite what I felt was proper care after only a few month's.
Wish I could help more.
Did note that the ones I lost ,,their Barbel's slowly deteriorated before succumbing, and it seemed to make no difference whether they were moved to sand substrate, or left in tank with smooth gravel.
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Aside from the temperature, I don't see anything of concern in your numbers and responses to my earlier questions.
Corys are sensitive fish. When something goes wrong in one of my tanks that has corys, they are without question the first fish to show it. Example, when I had a problem with fungus from Mopani wood, it was the change in behaviour by the corys that alerted me; I know of others who had corys die from this fungus but not other fish. When the canister on my 115g got a bit clogged, it was the sudden change in behaviour by the corys that caused me to notice it. The point here is that they must be acclimated carefully, but also they suffer a great deal by collection, transport, poor conditions in the store--and all this takes a toll. They are highly sensitive to ammonia and dissolved waste, and here I'm thinking of their transport to the store and perhaps home to you. It only takes a very minimal level of ammonia to seriously affect any fish, and the damage may not become obvious [i.e., by death] for some time.
On the temperature, assuming you have tank-raised angels and not wild caught, you should lower your temperature to 77-78F. Wild angelfish need warmth, but not tank-raised. Higher temperatures quicken the metabolic rate of all fish, requiring more oxygen, higher respiration--in short, the fish is working overtime the higher the temperature is, and this means a shorter lifespan. Always maintain fish at the lower end of their temp range, or as low as possible when considering all fish species in the aquarium. I have found 77-78F (25C) to be suitable for the majority of tropicals. Some require higher and need that--discus, wild angels, some gourami. But most manage fine at 77-78F. A couple degrees may not seem like much, but to a fish that is dependent upon the temperature for all its internal functioning, it can be significant.
Byron.
Corys are sensitive fish. When something goes wrong in one of my tanks that has corys, they are without question the first fish to show it. Example, when I had a problem with fungus from Mopani wood, it was the change in behaviour by the corys that alerted me; I know of others who had corys die from this fungus but not other fish. When the canister on my 115g got a bit clogged, it was the sudden change in behaviour by the corys that caused me to notice it. The point here is that they must be acclimated carefully, but also they suffer a great deal by collection, transport, poor conditions in the store--and all this takes a toll. They are highly sensitive to ammonia and dissolved waste, and here I'm thinking of their transport to the store and perhaps home to you. It only takes a very minimal level of ammonia to seriously affect any fish, and the damage may not become obvious [i.e., by death] for some time.
On the temperature, assuming you have tank-raised angels and not wild caught, you should lower your temperature to 77-78F. Wild angelfish need warmth, but not tank-raised. Higher temperatures quicken the metabolic rate of all fish, requiring more oxygen, higher respiration--in short, the fish is working overtime the higher the temperature is, and this means a shorter lifespan. Always maintain fish at the lower end of their temp range, or as low as possible when considering all fish species in the aquarium. I have found 77-78F (25C) to be suitable for the majority of tropicals. Some require higher and need that--discus, wild angels, some gourami. But most manage fine at 77-78F. A couple degrees may not seem like much, but to a fish that is dependent upon the temperature for all its internal functioning, it can be significant.
Byron.
So I guess I will start by lowering the temperature gradually, but I have more questions. Are there species of Cory Cats that are hardier than others? Is there one that you would recommend? I don't care for the Bronze Cory Cat which seems to be the most abundant. Also, when cleaning the tank, I am a little confused. I had read not to siphon the gravel because of the plants, but how do I remove the collected fish waste and decomposing food?
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On the corys: the commonly-available species are usually [emphasizing "usually"] the hardiest as most are tank raised. C. panda is an exception. C. anaeus (the Bronze you mentioned), C. paleatus (Pepper), albino forms of these, C. sterbai and its albino. C. trilineatus (sold as julii but almost never is). Other species are likely to be wild caught and available sporadically. If the tank is mature and stable, all will settle in fine in my experience. I have several wild species, and they are fine; but they go into an established tank.
To the substrate. You shouldn't be seeing waste and excess food; the latter means too much feeding. I have fine gravel and sand substrates and unless I deliberately poke into it I don't "see" anything. The waste gets pulled into the substrate where it is broken down by snails and bacteria.
I sometimes think people expect the substrate to be sparkling clean, but that is unrealistic. I may have as much stuff on mine as you do--if I take a magnifying glass I can see it;-), so it could be our individual perceptions? Just a thought. This is where a video would help.
Byron.
Waste is not visible on the substrate, I only see if I sift through the gravel with the siphon. The reason I brought it up was because of 1077's comment about bacterial activity on the substrate causing infection in the Cories barbells. I usually only feed once a day and I don't feel that it excessive, because I never see spikes in ammonia. As I said earlier in the post I do 50% water changes weekly and usually just glide the siphon over the gravel in the areas that are not densely planted.
Maybe, I will go with the Peppered Cory Cats, but they look kind of dirty. One of the fish stores in my area has had a supply of Metae Cory Cats. Are these Bandits? Do you have any experience with them.
Maybe, I will go with the Peppered Cory Cats, but they look kind of dirty. One of the fish stores in my area has had a supply of Metae Cory Cats. Are these Bandits? Do you have any experience with them.
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Yes, the Corydoras metae are nice; I have some in my 115g. I actually prefer Corydoras melinni, they are very similar but a little "sharper" looking in the dorsal stripe. We have many of the usually-seen, and several rarely-seen, species of cory in our profiles, check them out; each has at least one photo.
Barbel degeneration of corys is usually caused by one of two things: from sharp substrate, and from high nitrates. I find it very difficult to believe it can occur from organics or waste in the substrate. These fish in their habit dig through decomposing organic matter all the time, that is why they have barbels, to find food. Nitrates in their habitat are non-existent; all tests of Amazonian streams that I have ever seen have had nitrates never exceed 1 ppm, and often so low they cannot even be detected. My aquaria have nitrates around 5ppm, which is pretty low for an aquarium, and rarely do I see any barbel degeneration. Sharp substrates is easily avoided. The enriched substrates, both Eco-complete and Flourite, are in my view too sharp for corys; I in fact removed my corys from the 70g and moved them into the 115g which now has sand, and they seem much happier. The C. panda were having barbel issues in the 70g.
Your substrate "waste" sounds fine, exactly what I have, and that is perfectly normal and natural.
Byron.
you have to get the muck out of the gravel or at least stir up half of it. Sand is different, but you implied rocks. Sand is "glide over" and rocks are "dig in" Sometimes you have to replant stuff with small roots (the fast growers all have small roots) - but you can get a tool that simplifies that for under $15 so you don't need to get wet. i personally don't mind getting wet while cleaning/tidying a tank.
The consensus seems to be to only vacuum half the tank's gravel per water change.
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With respect I will disagree on this. I never touch the substrate, and most aquarists with planted tanks do the same. You can read how this works in this article on bacteria:
http://www.tropicalfishkeeping.com/freshwater-articles/bacteria-freshwater-aquarium-74891/
I believe it is always preferable to let nature do the work; it is after all very experienced after millions of years.:fish
rovided the tank is not out of balance, this works well.Byron.
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My apologies if I muddied the water so to speak, by posting my opinion's/ observation's,, as to possible causes for bacterial infection's or otherwise poor health of species in question.They were/are, merely observation's and my feeling's as stated ,not to be confused with cause and effect.
Stream's that these fish are found in and video's I have seen of same, indicate very little decomposing matter laying about or excess NitrAtes, due in large part to current's which carry organic's and waste away, and plant growth is sparse due to tree canopy in many area's, that block's light that plant's need.
Usually nothing but leaf litter and root wads,sand substrate, or smooth river stones along with moderate current in area's that these fish choose to inhabit.(my observation's)
I do not believe they use their Barbel's to dig ,so much as they use them for locating food by smell, or scent, in same way as many other catfish species do.
They do enjoy sifting through sand as opposed to gravel in my opinion while searching for food and it then becomes easier on Barbel's than rooting around in gravel be it sharp gravel or otherwise.
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If barbel degeneration occurs, check the nitrates. There may well be other causes, I only mention the two that are cited by the catfish people like Dr. David Sands.
To pick up on 1077's correct observations, organics are present in the sand substrate of streams. If there are worms, crustaceans and insect larvae in the sand that the corys are looking for, these creatures must be eating something. Plus there is natural waste from fish, birds, whatever that falls into the water. All this gets pulled into the substrate just as it does in the aquarium if there is a proper flow of water down into the sand. The fish/water volume ratio is obviously very much higher in the aquarium, so this is more evident. Plus there is the leaf breakdown creating its own organics and micro-plankton life.
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I think you are doing what can be expected.
It was unclear to me, as it often is without further info throughout post's, to determine what substrates are being utilized, and what food's and frequency of feeding's are.
With plenty of plant's ,there will be less problem with organic's creating problem's on substrate as there would possibly be otherwise for plant's will use the organic's as fertilizer's.
I also use (believe Byron does as well), trumpet snails to help further keep substrate clean of that which plant's don't readily use.
I keep a dozen (six each) of schwartz corydoras, and Melanistius corydoras, in planted tank and have yet to vaccum the substrate in nearly two year's.
I also as mentioned ,offer them a variety of food's as opposed to just letting them scavenge for what flake food the other fish receive.
I could not vaccum substrate if I wanted to due to plant mass, but I am careful to not overfeed the tank as you are as well.(once a day)
I have kept many species of these little fish and it is only the species in question here that I have had trouble with.
I do believe they fair better on a whole as species go, in fairly well established tank's of a few month's old as opposed to newer tank's, and I would not discount possibility of sick or weak fishes when purchased to be problematic due to stress of shipping,and or poor water quality in holding tanks at fish stores.
Just keep up with tank maint,qualtiy food's,and fishes will have best chance.
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I've found that comprehensive plant fertilizers are meant for tanks without a lot of fish. With my highly stocked plant tanks I only use micronutrients. The fish waste provides plenty of phosphorus and nitrogen. Those nutrients are high to begin with, and when you add your comprehensive fertilizer you are spiking the nitrogen and phosphorus. That could be your problem.
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