Cory Tank problems......

[bulati]

Hi, I hope someone can help me on some problems I'm encountering in my Cory tank.


1. Water parameters
a) 26c-28c
b) pH:7.4
c)Ammonia:0, Nitrate:10-20, Nitrite:0
d) Water change frequency:1x 40% a week


2. Tank set up
a) 20gallon
b) small round gravel
c) eheim 2213
d) Plants and mosses, some ornaments...
e) 6sterbai 5schwartzi 7zebra danios 2ottos
f) How long has it been set-up? 3months

3. Symptoms / Problem description
Basically I have two problems:
1) I am noticing that all my fish in the tank are scratching themselves on the substrate, plants, filter pipes etc from time to time. I do not see any symptoms of ich, velvet, fungus etc. no redness or slime on gills. Color of fish looks vibrant and eating fine except they are scratching from time to time. Ive been treating with Seachem Paraguard for two weeks already but I do not see any improvement. I was wondering if I need to treat them with something stronger or could my water conditioner with slime coat trigger this scratching(Nutrafin Aquaplus)?

2) Second problem, when I was cleaning my tank last weekend. I pulled out my ornaments, not knowing one of my schwartzi was inside. when I was done vacuuming and water change and about to return the ornaments, I did a headcount and noticed one of my schwartzi was missing. I found him lying on the floor and quickly returned him in the tank. He was outside of the water for nearly an hour. It took him around 2hours before he acted normal again(eating and swimming around) I thought he would be OK, But I'm noticing the past 3days he hasn't been moving much and not eating at all. Could this be the effect of hes out of water experience? If so what can I do to help him? he is just laying on the ground and twitches once in awhile, when I feed everyone would start eating while he just stay still. again I don't see any sign of sickness, just that he doesn't move much and eat. And I'm afraid I will loss him soon.

Sorry for the long post, Hope someone can help, Thanks!

[corypandas]

Hi,
Cories are very sensitive to nitrates so I would try to get your nitrates down to zero if possible or less than 10 if not. I do a test for nitrates when I see them scratching and almost always its over 10 and after a water change they are fine. If you are having trouble with nitrates try cleaning out your canister filter more often and do a really good gravel clean. Also you could add more plants to help soak up some extra nitrates. Also you could cut back on feeding a bit will help as well.
I would add some carbon into you filter for 2 days to remove any medications cories are very sensitive to it and can make the condition worse. Make sure you remove carbon after the 2 days as once its full it will release chemicals back into the water.
As for your other problem all you can do is keep the water quality spot on and hope he comes better with time, best of luck with your cories I hope it all works out,:d

[MatsP]

My experience with corys is that they aren't particularly sensitive to nitrate. My tap-water comes out about 30-40 ppm nitrate, and I have three species of corydoras as well as Brochis in that water.

And a little bit of scratching now and again is normal. It's if the fish scratch all the time that you need to medicate. All fish (like humans) will have a little bit of an itch now and again.

--
Mats

[2wheelsx2]

Hi,
Cories are very sensitive to nitrates so I would try to get your nitrates down to zero if possible or less than 10 if not.

I don't know if they are sensitive to nitrate or not (I have mine in planted tanks and dose to 10 ppm nitrates with KNO3), but it's impossible to keep nitrates at 0 even with a continuous water change system unless you have no fish in the tank. That's just straight biology, since the fish will excrete ammonia which is then converted to nitrite and nitrate by your bio bed.

[corypandas]

Hi,
I can honestly say I do not have nitrates and over the last few years the most I have ever had is less than 10ppm. I have a very good bio going. At first I had alot of problems with keeping cories and after alot of internet research I found that alot of people that had these problems had nitrate problems and recommended the same course of action I have done above. I followed the above advice myself and now have very happy, health and breeding like rabbits cories. All I can say is it worked for me. Good luck with your cories.