Why do my cory's keep dying?

[J.Mcpeak]

Test tap water for ammonia.
16g is a bit on the small side for Cory p. (unless you're trying to harvest eggs!)
Short term is ok but a tank that size would need 2-3 changes per week to keep the water clean and good.
Could be osmotic shock or ammonia related issues (toxic shock)

Do you use prime or am-quel or similar ammonia binding water products?
0.25 nh3 should be 0, unless your conditioner is one of the ammonia binding types.

 

[Nils]

The conditioner I use is the normal aqueon water conditioner, and I don't put anything else into the water except for that when I do water changes. My fish are all healthy now, and I know the tank's a bit on the small side, but it's the only size I have the space and money for.

Nils

 

[J.Mcpeak]

The conditioner I use is the normal aqueon water conditioner, and I don't put anything else into the water except for that when I do water changes. My fish are all healthy now, and I know the tank's a bit on the small side, but it's the only size I have the space and money for.

Nils

Finances aside,
Your fish are healthy for now, otherwise the title would not be, why do my Cory keep dying.
If it isn't water, that leaves few alternatives.

I've looked at Aqueon, apparently it neutralises ammonia, this may throw a false reading like similar products eg. prime and am-quel. 0.25 mg/l is the typical reading when using such products. Normally it lasts for 24 hrs, then it needs another dose, if the symptoms appear the following day, maybe it's that.


The only other thing I can think of, pH swings due to planting density. If you have lots of plants the pH will rise and fall over night, this is (or can be) enough to kill.

(While I think the tank is small, it is possible to keep these fish in it if you do lots of regular water changes to keep nitrates down, a greater volume of water will help with this, the cost of fish will soon equal a bigger tank)
A deep tank will have the same footprint but a greater volume.

 

[Nils]

Yeah, I hear what you're saying. I'm not heavily planted, but I have lots of different species of plants. I had no idea about pH changing over night, but it's good to know now. Right now all fish are healthy, and I'm not worrying anymore. I actually do think it is the water, so I went out and bought a couple jugs of spring water, and I'll be using these every time I want to do a water change because the tap is just to dangerous with all these chemicals and my conditioner that might not even be working. Thanks for helping me out.

Nils

 

[KidFish]

nils,
I may have good news for you, I used some aqueon stuff a few months ago, it killed all my fish. I never really figured out why it did that and neither did anyone at I talked to, however I did switch to prime and my fish are now all doing really well. I would really try and switch to prime, mix it in the water you are using before you put the water into the tank.

Hope everything goes okay


Sent from my iPad using Aquarium Advice

 

[Nils]

Thanks so much! I'll look for Prime next time I get a chance to go to the LFS, and that's definitely a red flag to look out for Aqueon now. Thanks for that! Sorry about your fish.

Nils

 

[Nils]

I got some Prime the other day, going to try my next water change with that and tap water, see how it goes. I think it's just the water and the conditioner that is killing my fish. Thanks for all your help guys!

Nils

 

[stooker]

Best of luck, I hope the situation clears up!

 

[LCB0612]

Gravel is really bad for cories, and the symptoms seem like they are chlorine poisoning, but I think you would be medicating the water. Add ~1/2 tsp. of API aquarium salt per gallon. I have 8 cories, one of whom is 9 years old, and I know salt is OK in small quantities for them, I know there will be a reaction, but, if there is some disease, 10 day salt baths are a cure all.

 

[Nils]

I have black sand with some rounded gravel scattered around on top. They all have good barbels and aren't showing signs of sickness anymore. I'm going to try tap water again with Stress Coat soon. Thanks guys!

Nils