Cory habrosus died today; some others seem listless or swim/lie oddly.

JoshOfMichigan said:

There's a website I used to determine compatibilities and stocking levels, well-known but the name escapes me right now. It recommended pH of 7-7.5.

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This points out another serious problem in this hobby. I don't know if you mean the Aqadvisor site, but it is not that reliable, and none of these can be anyway, because they cannot possibly factor in all the necessary data involved. And to recommend a pH of 7.5 for fish that are programmed to function best in a pH of 5 or 6...well, that's not reliable is it?

For most fish tank raised has not much to do with it. The fish species' genetic design is not going to be changed unless the fish can evolve over a period of many years. The "adaptation" of some species usually has a biological reason for it, and every species is certainly not going to respond the same.

@Bryon The issue with your example is that you have heavily planted tanks and quite low nitrate levels. In your case your nitrates measured would be within only the 1st category or division of the test, i.e. the resolution of the test is not precise enough to capture the change. If you had a test that was more precise I am sure you would find that if you removed 50% of the aquarium water and then added an equivalent amount of nitrate free water that the nitrate levels has to drop by approximately 50%, simply because you remove 50% of the dissolved NO3 during the water change. This is a basic chemical solute/solvent relationship, https://www.fishforums.net/threads/nitrate-test-assessment.468948/.

Right now pre change you might have an actual concentration of 4.5 ppm and after water change 2.25 ppm, both end up in the 0-5 ppm category so that shows no change. This is an nearly ideal situation and one you target, unfortunately I don't think the majority of aquarists have the same devotion that you have shown. It is also likely that the color changes in the test kit are not linear, though I cannot truly speak to that issue.

An example of the assumed nitrate readings from on of your aquariums:

• Starting nitrate 2.5 ppm
• After one week 5.0 ppm
• Delta 2.5 ppm per week (a week of nitrogenous metabolic waste build up = 5 ppm Waste from food and fish waste - 2.5 ppm diverted waste due to plant takeup of ammonia)
• Assume 50% change once a week.

In this case the total nitrate concentration never exceeds the 5 ppm level so you get no indication of a nitrate difference with the API test kit.



If you would look at a tank with the same schedule but perhaps no plants you might end up with something like below:

• starting nitrate 5 ppm
• end 10 ppm
• 1 week assessment
• Delta 5 ppm wastes from fish and food and no takeup from plants.

In this case the API results bounce from 0-5 range(Yellow) into the 10 ppm range (Green)



Using relatively low nitrate accumulation and typical 70s water change frequency you get a quite different result (20% every month), might explain why there seemed to be more "sensitive" fish then, they were slowly getting poisoned. Max NO3 47 ppm but we approach that level after about half a year or more.

Literally *everything* else I've read says keep nitrate low, with a reference of under 40ppm for most and under 20ppm for sensitive species like cories. & if you can get it lower, good. Sometimes it's been at 5ish, and that usually gets compliments, not "it's too far above zero". I'm looking to keep my animals alive and healthy, not create an exact natural biotope. I know you're trying to be helpful, but can someone less OCD chip in? I feel like this is becoming an opportunity for people to show off, not address my cories' needs.

I don't know what OCD means, but never mind. You can accept or reject my advice, that is your prerogative. The fact is though that nitrates above 20 ppm are detrimental to fish. Any ichthyologist or biologist will tell you this, and it is now being said by most all reliable sources. All cichlids are especially sensitive to nitrate, and on the cichlid forms they are advising to keep nitrates low, below 20ppm, as there is increasing evidence that diseases like hole in the head is nitrate-related. If you care about the health of your fish, you will work to keep nitrates as low as possible. The fish will be healthier for it. Nitrates weaken fish over time; the extent depends upon the species, the level of nitrate, and the exposure time.

Information changes as the science develops. Hopefully we move with the times for the sake of the fish.

Byron said:

I don't know what OCD means, but never mind.

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Obsessional Compulsive Disorder...a serious mental health condition, but one that is nowadays randomly and casually applied, usually in a derogatory fashion, to anyone with attention to detail.

Byron said:

The fact is though that nitrates above 20 ppm are detrimental to fish. Any ichthyologist or biologist will tell you this, and it is now being said by most all reliable sources.

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Agreed.

I actually have diagnosed OCD, FWIW. It's not attention to detail I'm complaining about, Bruce. If either you or Uberhoust has any useful advice, go ahead. Otherwise, why are you posting? At least I can act on *something* that Byron is saying.

My point is that I didn't come here either to be upbraided for not having a biotope, or for folks with 20 years of experience to have phallus-measuring technical arguments with each other so they can look smart. I *do* keep my nitrates under 20, generally *well* under 20. They're under 10 atm. I have a 9-month-old tank, though. It's not going to act like a decades-established aquarium.

I came here to ask for immediate help for my cories, within the *real constraints I'm operating under*, not to hear about every deviation from a biotope ideal. Now if anyone who gives enough of a rat's behind about my fish to do that wants to give me some practical advice, that'd be appreciated.

So far, I've been able to use Byron's information about potential risk from wood fungus to justify a deep-clean of the tank and decor, and I appreciate that, but that's been the *only* thing anyone's said that I've been able to act on.

I just checked the conditions of my hospital tank, and the pH is above 8. Since chemically altering that number has already been heavily discouraged, that rules out immediately moving the sick fellows over.

I'm tempted to try the triple sulfa I have on hand in the main tank, since it's relatively safe for animal cells and supposedly won't harm my cycle, but I'm reluctant to indiscriminately medicate and also to remove the entire cartridge that contains carbon. I have other pieces of old filter media in, too, too keep the bacterial colony high, but don't know how much of a blow it can safely take.

How about a yes/no on the wisdom of that, and also suggestions about anything else I can do in the next 24-48 hours or so (i.e., not a full tank breakdown and resubstrating or setting up entirely new tanks to separate animals that are, so far as I can tell, at least tolerant of each other)?

After all, this category is supposed to be for *emergencies*, not long-term improvements, isn't it?

JoshOfMichigan said:

My point is that I didn't come here either to be upbraided for not having a biotope, or for folks with 20 years of experience to have phallus-measuring technical arguments with each other so they can look smart. I *do* keep my nitrates under 20, generally *well* under 20. They're under 10 atm. I have a 9-month-old tank, though. It's not going to act like a decades-established aquarium.

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No...you came here because, in spite of your knowledge and experience, your fish are dying and you're looking for clues as to why.
You would then be hoping for possible solutions that you can then adopt.

Unfortunately, in order to be able to give valid answers, we do actually need a whole load of info. If we were sat around a table discussing this, the assessment would take mere minutes and then we could start looking at fixing whatever was the issue here.

JoshOfMichigan said:

folks with 20 years of experience to have phallus-measuring technical arguments with each other so they can look smart.

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You need to appreciate that whilst there is a lot of science, with very real facts involved, as opposed to opinions, there is also an art to fishkeeping and this is where discussion occurs and differences of opinion. This is especially true when we have different solutions to offer, based upon our own very subjective and usually unique experiences.

JoshOfMichigan said:

After all, this category is supposed to be for *emergencies*, not long-term improvements, isn't it?

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We'd also be hoping to fill the gaps in your knowledge with enough useful info, so that you wouldn't experience the same issues again, at some time in the future...so yes...long-term improvements would be considered and suggested.

JoshOfMichigan said:

It's not attention to detail I'm complaining about, Bruce. If either you or Uberhoust has any useful advice, go ahead. Otherwise, why are you posting?

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I was answering Byron's question.

You do not need to uproot the entire aquarium's scape to install a sandy beach area for the Cories to enjoy without being hurt by the gravel.......sadly the gravel can easily damage their barbels, thus introducing infection with the potential of killing them.

To place a beach area quickly and easily can be done when doing a water change. Drop the water level by around 75%, this will not harm anyone in the aquarium. Get a 2 litre or larger plastic water bottle (you can use a fizzy pop bottle as long as you wash it out extremely well). Cut the bottom off the bottle to make a funnel. Turn the bottle upside down and use the neck of the bottle to gently shift the gravel to leave bare glass bottom - try and do around 20 to 25% of the existing gravel to give the Cories lots of room to play and sift safely. Once you have your clear space, grab an extra pair of hands if you can, get a jug or large mug, fill the jug or mug with sand, hold the neck of the bottle no more than one inch above the glass bottom of your aquarium and very very slowly pour the sand down through the upturned bottle. Keep the bottle moving slowly to give a nice even coverage of sand to the bare area. Repeat until you have 2.5 to 3 inches depth of sand. Doing it extremely slowly with the bottle should prevent sand clouding the water.

That will give you a nice area of sand for the Cories to play, to sit and rest and to snuffle in for food etc.

Cleaning can be done with a turkey baster....spot clean by using the baster's suction....sand puffing to prevent noxious gases gathering by filling the baster with aquarium water and gently puffing the water deep into the sand, when you do that, there will likely be detritus on the top of the sand which can be spot cleaned with the baster.

Thank you. Any opinions on whether triple sulfa might help with the immediate concern of bringing some of these fellows back to health?

JoshOfMichigan said:

Thank you. Any opinions on whether triple sulfa might help with the immediate concern of bringing some of these fellows back to health?

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Without knowing the actual issue (and so far from this thread you/we don't), why would this Triple Sulfa be beneficial? I think I mentioned previously (though it could have been in another thread) that Corydoras are sensitive to any substance added to the water which can diffuse across the cell membranes and enter the fish's bloodstream, and as this product is intended to be dissolved in the water, it obviously can enter the fish. It is an antibacterial but nothing has been mentioned indicating this is the issue. Someone like @Colin_T is needed to look at this, though I see he did previously post here.

I haven't seen him post anything here?

My thought is that all this talk of gravel and sand revolves around bacterial susceptibility. If it's something bacterial, triple sulfa might at least arrest their growth and give the ill cories a chance to fight off any infections, especially with how aggressively clean I'm keeping the tank right now.

That and the cory I thought was going to die a couple months ago and is now healthy (he had the same initial symptoms, but also jumped out of the hospital tank onto the floor, which put him in even worse shape for a while) was treated with triple sulfa, then kanamycin. I think kanamycin would be too aggressive a medication for a community tank, though.

JoshOfMichigan said:

I haven't seen him post anything here?

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Post #3 in this thread is Colin.

JoshOfMichigan said:

My thought is that all this talk of gravel and sand revolves around bacterial susceptibility. If it's something bacterial, triple sulfa might at least arrest their growth and give the ill cories a chance to fight off any infections, especially with how aggressively clean I'm keeping the tank right now.

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I am simply questioning the use of any medications unless one can be fairly certain of the issue. These antibiotics are not advisable unless they do target the bacterial issue if that is what this is; personally, I doubt it, but my experience with fish disease is so minimal as to be next to zero, and someone like Colin is far more experienced, not that he has tanks of diseased fish but more his years working in a fish store.

Kanamycin is good but only if the issue is a specific bacterial one. I did once have a form of columnaris, and with the asistance of an online marine biologist I used kanamycin and furanizole together; it worked, but it can also kill the fish if it is not being properly used because it then only adds more stress without any benefit.