PlanetCatfish.com

Hi, I'm a reasonably experienced fish keeper; I've kept largish tanks and bred bristlenoses, gouramis, dwarf chichlids among others. I love catfish best (especially lorachariids) but I'm keeping a small easy maintenance tank these days due to a very hectic schedule!
I'm a bit worried about my Corydoras Similas;

1. Water parameters
a) 27?C
b) PH 6.8-7.0
c) GH.
d) KH
e)Ammonia = 0, Nitrate = 0, Nitrite = 0.
f) weekly water change

2. Tank set up
a) Size 22gallon.
b) Substrate = dark, small pebbles.
c) Filtration = built-in filtration on an Aqua One AR-620 ; the water is sucked up by a powerhead into a filter that runs along the top back of the tank. It has two levels of sponges and 'spaghetti' and I have used 'cycle' in it to boost the bacterial population. The water runs out through a tube creating movement on the surface of the water.
The only additives i put in the water are de-chlorination product and stresscoat when I get new fish.
d) Furnishings = lots of plants; marbled queen swords, swords, various other plants.
e) Other tank mates = 5 x serpae tetras, 5 x lemon tetras, 1 x opaline gourami (female), 1 x hillstream loach.
f) How long has it been set-up = about 2 months and the corys have been there for about a month

3. When I first got my 5 Similis corys they were very active and quickly coloured-up to have orangey bellies and reflective sides, they also started exhibiting breeding behaviour! A week ago one of them died for no apparent reason and my first thought was that i had a water quality problem but none of the other fish in the tank seemed to be affected at all and when i checked the water it was fine.
Since then the Corys have become very lethargic and don't seem interested in their food. They just sit at the back of the tank or under their log and look miserable (if this is possible for a fish!)
All the other fish in the tank are healthy - the tetras and gourami in particular are very active with extremely vibrant colours. It's probably also worth pointing out that the corys aren't harrassed by any of the other fish either.
I feed then a mixture of shrimp pellets and frozen food + they seem to enjoy the occasional sprilina tablet that I put in for the loach.

4. Action taken = none apart from keeing up with water changes and monitoring water quality

5. Medications used = none

advice??

i would say that the tempreture is too high, they prefer a temp of around 21-23 degrees. ive just spawned these again and the temp was 21C you'll find them more active if you drop the temp a little bit
all the best
stuart

Thanks Stuart!
How will the drop in temperature affect the other fish in my tank; tetras, gourami?
I figure the Hillstream Loach will be happy with that seeing as they like a lower temp anyway...

i keep a few species of tetra and dwarf cichlids with my cories all at around 74F (sorry to change from centigrade)
with no adverse results, infact quite the opposite. i think they benefit from being kept slightly lower unless you intend on breeding some species such as plecs, tetras and apistos which require a little higher temp.(around the low eighties)

Hi Stuart
I dropped the temp 2 degrees since yesterday and they have already perked up so i can see that the lower temp definitely suits them better! I did a bit of research into the prefered temp range of the other tankmates and they are all quite happy at around 24 degrees so I'm going to gradually take it down to that temp for now and see how they all go.
I guess I was used to having a higher temp because my last tank was a bristlenose breeding set-up (with some other tankmates that didn't eat the fry - the bristlies would only breed in a community aquarium damn them!)
thanks for you help, that was perfect advice