Cories acting wierd?

Cories will do that - especially when first introduced. They just get overly stimulated and don't calm down. When they zip to the top of the tank, that is them taking a little extra air in (kind of like a betta, but not as reliant on it). Don't worry about it.

4 of them is enough in your tank and it's also not a big deal that they didn't school.

So far so good

On a side note, those glowlights would probably like some friends and I don't know how well tiger barbs (esp. only 4) will be with the rest of your fish.

I hope it is OK to revive this old thread but it seemed relevant to my current concerns. As those of you who have been following this section of the forum know I picked up 6 corydoras aeneus on 05 Mar 2005. When they first arrived they seemed fairly casual about things and would even hang around near my hand while I was doing some ham-fisted aquatic gardening. Now when I do so much as walk near the tank a few of them go *ballistic* and just race around the tank wiggle through the sand or whatever it takes to not be seen. Some of them just stay still in the clay pot or slate "caves" that I made for them. Is it normal for them to become this skittish? I have been visiting them at least twice a day. When I drop some food in they go after it and if I sit still a few feet away and watch them they seem OK with that after a while. I'm hoping this is normal it just seems a bit wierd after they used to be so calm.

My corys did that too, and I freaked out too, but they did quiet down eventually. But any change in the tank, and they are all wound up again! Its kind of fun to see them actually moving.

Now things are really not looking good. A few of the corys seem to be flashing or rubbing against gravel and rocks. There are also sort of flat, clear, oval shaped "scabs" on the side of the glass. There are also a few free swimming wormlike creatures. While I suspect ich to explain the flashing, I still don't see any of the white spots typical of an ich infection. So far the corys are eating and not acting too listless. I am think of treating the tank with some form of ich medication but I do not want to jump the gun. Any thoughts?

Firstly, the spastic behavoir can be caused by a few things. One is that the tank is too bright for them (remember, they're nocturnal). It could also be that they don't feel there are enough hiding places, particularly dimmed or darkened ones. If you have a very light/bright substrate this may also be a factor. That said, it could just be the way they are. While they are not cories (closely related, commonly called cories), my Brochis splendens are very skittish no matter what.

As for the flashing, ich infestations usually occur in the gills first - where you can't see it. Keep a very vigilant eye out for the first signs of something wrong. I'm not one to medicate before I'm sure its necessary, especially with scaleless fish like cories. But the moment that you see a white spot, I'd use the salt/heat method.

As for the "scabs" are they baby snails? What do they look like?

The worms, are they red/pinkish and round? They sound like a roundworm; they're not dangerous to your fish (the fish will eat them) but it indicates that there may be too much waste in the system, ie dirty substrate, old food, etc. Try gravel vac-ing more and not overfeeding.

Some interesting suggestions. I never considered the brightness part. I have a single 20w tube over a 38g tank. I also have a pot cave and a slate cave and there is a java moss thicket they seem to like going behind. Substrate is medium dark (brown pool filter sand).

I have my eye out for advancing ich, believe that. The "scabs" are hard to describe. If memory serves me right (can't see any right now as I just did a water change). They have a clear perimeter with a dark nucleus and are about maybe 5mm in length).

The worms are of varying length up to a centimetre or so, round and white. I am still trying to establish a cleaning routine for the tank. I did my 1st weekly change last weekend and swapped out 10%. This seems to not be enough as nitrates today were 20-40ppm. I did a 40-50% water change (can only gague by eye with python) and nitrates are now 10ppm (ammonia and nitrites were 0ppm).

I try not to feed too much, usually just 1-2 pellets per meal twice a day. I will cut back to 1 feeding per day and stick to 40-50% water changes per week and see if that helps. I also suspect a not-so-healthy plant may have ben contributing to high levels of organics in the tank. The plant has been removed.

Thanks again for the advice. I'm keeping my fingers crossed.

Well, my little guys seem to have stopped whatever flashing they were doing and aside from being a bit skittish when I show up they seem to be doing OK. Perhaps that 40ppm nitrates were causing them some distress? For feeding I am now breaking a single sinking tablet in 2 and then taking the pieces out after 20 min or so. Still seeing some of the wriggly things but I wil keep up with bigger water changes (25% weekly minimum). If it is not too much trouble can anyone please describe in detail their methods for feeding corydoras. I am just wondering if there is a better way for me to do this in order to ensure that the tank is not overfed.

I keep an eye on how big their bellies get after I've fed them. They will get "fat" looking when they're full, but they will cram more food in if they can.

Basically just keep an eye on how much they can eat and you'll get a feel for how much to feed them. Mine seem fine and that's all I do. Keep in mind that they're always scavenging around the substrate for a kibble, doesn't necessarily mean that they need food.