Pygmy Cories

[FrozenDeth]

I have a 15g low light planted tank set up for about 4 months now. Residents were 6 cardnal tertras 2 red cherry shrimp and a hillstream loach (I think, gf come home with him, the lfs said butterfly pleco) I added 7 pygmy cories about 2 weeks ago and everyone was doing great. It was a blast to watch the cories swim around together and perch on the leaves.

Now the porblem, since monday I havent had alot of free time and besides feeding I didnt have time to enjoy watching my tank. Now last night I went to remove a couple of leaves growing over the water level and saw one of the corries laying on his side. I thought he was dead and went to remove him and he swam in a small circle and landed upside down and didnt move. I looked around and only saw 2 other corries(swimming around fine) and I looked all over the tank. I can only assume they died and my loach/shrimp/snails took care of the bodies. Well this morning the sick cory was dead, I have no idea what could be happening, water parameters are all fine checked them monday morning and last night, and all the other fish/shrimp are acting and eating normal.

If anyone can give me any advice or info I would greatly appreciate it because I was really enjoying having them in my tank and would think about adding more but I wouldnt want to sentence them to death by doing so. Also If any additional information would be relevent please ask.

 

[mfdrookie516]

join the crowd. alot of us have had unexplained deaths in our tanks. did you add anything new to the tank? any temp/param changes in recent weeks? Any signs of sickness other than what you mentioned above? Any pesticides sprayed nearby?

 

[FrozenDeth]

There has been a change in temp, it was warm last week so with the heater off the tank was at 80 most of the time anyway and the last few days have been cool and my tank heater was set to 76. But the cooling would have be gradual as the temp outside dropped monday night.

 

[Jedd]

My pygmy corys went the same way. I have no idea what happened.

 

[JustOneMore20]

What are your water parameters (ammonia, nitrite, nitrate, pH)? Dwarf Cories (and other Cories too) tend to be sensitive to the slightest bit of ammonia or nitrites and elevated nitrates. Also, has your pH stayed the same as far as you know? Slight changes in pH tend to kill them off as well.

 

[FrozenDeth]

Ammonia- 0ppm
Nitrite- 0ppm
Nitrates- 20ppm
ph-7.3-7.5 cant tell exactly but stays constant

Tested monday, thursday and today no changes across the board and did a 30% water change on thursday.
Down to 1 hope he makes it

 

[mfdrookie516]

how do you acclimate your fish? if the lfs has different water params and you just sit them in your tank until the water temp is the same, then dump them in, that could be a problem. If you dont already, make sure that any time you acclimate fish, you put some tank water in the bag in 30 minute to one hour increments. Like ill sit them in the tank for an hour, then add half a cup of water every 45 minutes or so until ive got the bag almost full, then ill put them in the tank. That gives them a chance to not only acclimate to the temperature, but also the water itself. Just a thought, but if you dont do that, it could be a delayed reaction to the shock of diferent water parameters

 

[FrozenDeth]

I use the drip method I think its called, read it on here a few months back. I put the new fish w/ water into a container and use an air hose and the ajustment attachment to drip tank water into the container. Usally do this over 1.5 to 2 hours.

 

[mfdrookie516]

yeah, thats what they call "drip acclimating"... idk, could be some disease they got at the lfs... i think lately about everybody has had bad luck with buying fish, only advice i can give you is dont give up, if youre doing everything right, its not your fault

 

[JustOneMore20]

Sounds like you are doing everything right. Sorry about losing most of them. Sometimes elevated nitrates can kill cories, but 20 isn't that high. If they were like 40, then I'd say it could be the problem (but not likely). I would try a different lfs if you can, if/when you decide to get more.

 

[FrozenDeth]

Thanks guys for reassuring me that it was most likly not a error on my part. Ive been enjoying the tank alot and spend the time maitaining it, but its my first tank in 8+ years and want everything to work out. This is the first time I purchased fish from this store, but the tanks were all really clean and Ive heard good things about it. Think I might try a differnt type of fish to be on the safe side, Im open to suggestions.