creaturemd

[creaturemd]

I'm having a problem with fish loss in one of my tanks. This tank is heavily planted. The fish die suddenly with no apparent signs of disease or illness. I've tried altering the water parameters and increasing water changes but nothing seems to help. New fish typically due well for several weeks up to a couple of months before dying suddenly. They eat well, behave normally, one pair even spawned prior to their demise. You will find a detailed description of my tank and water conditions in a previous post on the apisto forum. To make a long story short...I'm considering chemically treating this tank with a parasiticide and an antibiotic prior to introducing more apistos (as a preventive measure). I don't know what I'm treating so I hope to use something broad spectrum. Can anyone recommend a couple of treatments (chemical as well as protocol) that will minimally effect my biological filtration and do the least damage to my live plants? As an aside, I think I failed to mention in my earlier post that this tank is an acrylic hex which makes it 1.5-2 feet deep with a floor space not much larger than a ten gallon. I'm only trying to keep one pair with a small school of dithers and a couple of bottom feeders. Is the depth of my water or the small floor space potentially detrimental to apistos? There is a lot of cover (mostly driftwood with some lava rocks) creating small hiding areas at various depths. Thanks for any input!
Heather

 

[tjudy]

Hi Heather,

When the fish turn up dead, do they have a particular body posture? Specifically I want to know if their gills are somewhat flared and mouth agape.

How is the tank filtered? You describe a fish load that is by no means too much for the tank, but I am wondering if you might be experiencing a periodic oxygen depletion that might be causing the problem.

IME, systemic bacterial or parasite infestations are not only rare, but generally affect fish negatively before they die. When fish jus turn up dead, IME, a water quality parameter is to blame.

 

[creaturemd]

body posture...YES!!! Your descripion is identical!

Virtually all of the fish that I've found dead are indeed in the posture you describe. I was thinking possibly gill flukes as those that I've observed dying do typically exhibit rapid gill movements suggestive of respiratory difficulty. HOWEVER, other fish in the tank seem unaffected. I've never observed fish surfacing for air, which I assume would be evident with an oxygenation issue. My CO2 system does operate continuously though (night and day), but pH levels do not vary considerably on A.M. and P.M. measurements. Your accurate description of the posture gives me hope that maybe an answer is on the horizon! I hope you will comment on this new information and give me some new possibilities to explore. Thanks!

Heather

 

[tjudy]

Somewhere in here is a thread that discusses the interaction between CO2, pH and oxygen levels. There has been some research that indicates that eleveated CO2 not only reduces pH, but it may also reduce oxygen in the water. I will try to find it; maybe someone else will find it first and post the link here.

If you are seeing respiratory distress prior to the fish passing on, and it is only one fish at a time, then I will lean towards the pathogen hypothesis.

There is one other pH and CO2 realted possibility to consider. If your water has a high KH (carbonate hardness), then the pH will not drop significantly at night with added CO2; but the CO2 is still there, and it may have a detrimental affect on oxygen levels. Are you finding the fish dead in the mornings?

 

[tjudy]

Here is that thread:

http://www.apistogramma.com/forum/viewtopic.php?t=396