Corys Hypersensitive To Nitrates?

[Rynofasho]

2 of my 6 Corys look a bit off, and 1 actually looks like he is now going to die. I noticed today that their barbels were very short in comparison to the other 4, and their coloration was very dark. The also seemed a bit sluggish, and their pectoral and anal fins looked clamped, like they are just in straight lines with no texture.

I know my nitrates yesterday were maybe a touch over 40ppm, however all other parameters were fine. Since they looked suspect, I changed 30% of the water and started vacuuming where an algae wafer had been, and I pulled a TON of crap out of the substrate. I'm talking tons.

I'm afraid of high volume water changes dues to my abnormally high tap pH, so typically perform several small ones and may perform another tonight in a couple of hours.

To make things worse, my tap water suddenly is loaded with ammonia which scares me, so I doubled up on the Prime dosage.

No other fish in the tank show any signs of stress. It is also worth noting that the two Corys who appear to be dying are the two smallest.

A few questions here:

I have gravel substrate which I know isn't optimal, but the stones are smooth and every other Cory looks great. I have about 1.5" of gravel though. Is that too much? It seems like I'm just begging for a build up of gunk down there. How deep of gravel do I need for root plants?

For those who feed messy bottom feeders, how do you feed them? For example with that algae wafer and the few others I put in there, the Danios and Cats tear it up and I'm sure that most of it now ends up buried in the substrate. Perhaps put the algae wafers in a dish (the catfish wafers dont seem to break up and make such a huge mess)?

Do their barbels ever grow back if lost? I've seen mixed opinions.

 

[waterdrop]

In my opinion cories do appreciate well changed and low nitrate tanks. I would hope their barbells could grow back but I'm not an expert on this. It is also true I believe that most cories appreciate a softer, more acid environment, but as usual, stability is more important. Sorry not to be of more help. WD

 

[notg2009]

2 of my 6 Corys look a bit off, and 1 actually looks like he is now going to die. I noticed today that their barbels were very short in comparison to the other 4, and their coloration was very dark. The also seemed a bit sluggish, and their pectoral and anal fins looked clamped, like they are just in straight lines with no texture.

I know my nitrates yesterday were maybe a touch over 40ppm, however all other parameters were fine. Since they looked suspect, I changed 30% of the water and started vacuuming where an algae wafer had been, and I pulled a TON of crap out of the substrate. I'm talking tons.

I'm afraid of high volume water changes dues to my abnormally high tap pH, so typically perform several small ones and may perform another tonight in a couple of hours.

To make things worse, my tap water suddenly is loaded with ammonia which scares me, so I doubled up on the Prime dosage.

No other fish in the tank show any signs of stress. It is also worth noting that the two Corys who appear to be dying are the two smallest.

A few questions here:

I have gravel substrate which I know isn't optimal, but the stones are smooth and every other Cory looks great. I have about 1.5" of gravel though. Is that too much? It seems like I'm just begging for a build up of gunk down there. How deep of gravel do I need for root plants?

For those who feed messy bottom feeders, how do you feed them? For example with that algae wafer and the few others I put in there, the Danios and Cats tear it up and I'm sure that most of it now ends up buried in the substrate. Perhaps put the algae wafers in a dish (the catfish wafers dont seem to break up and make such a huge mess)?

Do their barbels ever grow back if lost? I've seen mixed opinions.

High nitrates and ammonia might have damaged the gills. You can use something like this (what I use) to turn toxic nitrogenous chemicals into a non-toxic form that your bio filter can still break down and use. Also sharp edges of gravel can damage their barbels, which in turn can get infected by some parasite. I'm not an expert on corys, but maybe gill damage is something you should look more into. Take a look at this page for some general info on corys: CORY CATFISH
I have gravel in my tank and have not noticed any problems my corys having with it, but they can certainly damage their baebels.
I use shrimp pellets to feed them, and these pellets stay intact for some time until they eat it all up.

I hope they stay alive and get better. good luck.

 

[Rynofasho]

Welp I can tell you the ammonia is not high as I test it regularly. As menial a task as it may be, perhaps I'll go through and remove much of the gravel that is not perfectly smooth.

I realize it is rather hit or miss, considering only two look affected and they were the runts anyhow, but I'm hoping I can at least learn something from all this.

The one is not dead but may as well be, the other looks decent, fins mildly clamped (in all honesty they almost look deformed). The dorsal fin is not clamped which I would expect it to be if he was really stressed. Barbels are definitely short, but don't look red or irritated.

I suppose I will just keep my eyes on all of them and closely monitor my water chemistry to bring those nitrates in check. I guess this would also be a good time to finally get some more live plants to suck up the nitrates as well.

 

[notg2009]

I searched the web and couldn't find anything specific. Have you ruled out fin rot? Fish Diseases

 

[Aqua Tom]

Markings are dark? Not usualy a sign of a problem. If a fish isnt well it usualy looks washed out colourwise.

Live plants cant do any harm & may actualy help. Carefull or you will get hooked like I have.

I am now addicted to seachem flourish.

 

[waterdrop]

(watch out Tom, the next stage of addiction is all 6 of the flourish types and seeing what dosing variations can do for you, lol)

 

[Rynofasho]

Yep, he's super dark. BARELY breathing this morning. Wish I had some clove oil

Going to change the water again this morning before I head to work, but he is in the same spot as 7 hours ago and gills are barely moving at all.

 

[karin]

Have you posted this in the cory section? Maybe more help there. I can say that throughout this start up year of my tank I have had variable nitrAtes and the corys have made it through very well. I think with a lot of the fish that are very popular they are just so bred and inbred that there are a lot of weak individuals out there.

I have a tank with sharpish gravel and I won't get anymore softbelly fish until I change it out. I've lost 4 plecos to it I think. Good oxygen is also important to corys, So good disturbance of the filter outlet and/or a bubble bar or airstone. While I know that everyone says an airstone does nothing, I have seen it revive fish in tanks that were having an oxygen problem so I always have one around to through in. Maybe it is worth a try, at a minimum the corys seem to like bubble bars to play in. Corys also like cooler water. 24-25C.

Good luck but it doesn't sound great.

 

[Rynofasho]

I ended up putting the one Cory down He hadnt really moved at all in over 24 hours, and his gills were barely moving at all so I thought it best that I put him out of his misery.

I've vacuumed the heck out of the tank, cleaning up GOBS of nastiness, so I think I just let the nitrates / detritus get away from me as I didn't think that so much of the wafer food was finding its way through the substrate (even though I clean weekly).

The long term solution I'm going with is sand substrate -- obviously it's easier on the barbels and it will greatly reduce the amount of crap that gets out of sight and contributes to poor water quality. I won't be able to get all the plants and have the time until next weekend, so I'll keep up with 30% changes and thorough gravel vacuuming and hope that everyone stays healthy until then.