Slowly losing fish

[Pickoff]

I've been losing a fish every 3-4 weeks. My 65 gallon African tank was setup in January and everything seemed to be going very well. I hadn't lost any fish until I went on vacation at the end of June.  I lost one while I was away and since then I've been losing a fish every time I perform a water change (3 weeks).

The fish are not showing any physical signs of illness other than heavy breathing and pale coloring.  The last one passed away last night.  He was hovering at the bottom of the tank when I first noticed him and was breathing heavily.  He was in bad shape at the end.  His scales were coming off, his eyes were puffy, he looked like he was 100 years old.

My suspicions are that the deaths are related to the water changes.  I have a deep sand bed (3-5 inches) of crushed coral which I vacuum when I perform the water changes.  Could there be some lethal bacteria in the sand bed?  Also, when I turn my cannister filter back on, the first spray of water in the tank carries hundreds of white flakes.  What are these white flakes?

Any comments would be greatly appreciated.

[Marc]

Without seeing them I can only guess that the white flakes are  flakes of crushed coral.  You should clean out your filter to get rid of them.  

I can't really say what is causing your problems but I suggest that instead of changing your water every three weeks change 20 to 25% of the water everyweek.  Make sure you add dechlorinator to the water.  The more frequent water changes will mean less change in the water chemistry when you do your water change.

HTH

[Nelson]

I'm FAR from an expert but I can describe my regime for my 120, 35 and 10gal tanks for what it's worth.  I conduct a 20% water change and vacuum every weekend.  I feed sparsely once a day to avoid build up of uneated food.  My substrate is coral and approximately 1.5-2" deep.  I clean my cannisters (4) and hoses every 4 to six weeks taking care to preserve as much bacteria as possible.  Incidentaly, the white flakes you see is crud that builds up in hoses and piping.  I don't know if it has any beneficial qualities but I don't like it and remove it anyway.  

I"m not sure what the solution is to your mortality rate, I'll leave that for the many experts in the group. But as you can see there seems to be quite a difference in our situations.  I've been very successful with my tanks in that I've only had one death in my fairly heavily populated show tank and the water in all tanks is crystal clear and within accepted ranges.

Hope this helps a bit.

[328iGuy]

My initial question would definitely be do you use a dechlorinator during water changes and if so what kind?  How do you apply it during the water change cycle?

[artw]

I have a deep sand bed (3-5 inches) of crushed coral which I vacuum when I perform the water changes.  Could there be some lethal bacteria in the sand bed?  .

Not bacteria but you could be releasing methane gas or something when your deep sand bed goes anerobic.
when I used sand I only had 1" and it STILL compacted.
now I use NO substrate in all except my 2 show tanks.  and even that is a thin layer of gravel.

now I'll ask the obvious
Dechlorinator?
PH before/after?
Temperature?

I agree with Nelson regarding maintenance procedures I only wish I had the time to do all of that in my tanks

I do 75% wc's in my fry/juvie tanks and 50%-75% in my adult tanks once every 2 or 3 weeks with great success

[gvv]

The fish are not showing any physical signs of illness other than heavy breathing and pale coloring.

When I once left my overcrowded tank without filter and air running for more than 8 hours I had the same. Fortunatly for me everything finished without any loose. But they behave exactly as you describe.
Have you ever checked the parameters of your tap water? This seems very strange. Check with the parameters provided by David: http://ovas.ca/bridge/phpBB/viewtopic.php?t=281
And, BTW, I never add dechlorinator if changing 15-20% of water for adults weekly (if more, than I use), but never loose a fish because of this.

[Marc]

And, BTW, I never add dechlorinator if changing 15-20% of water for adults weekly (if more, than I use), but never loose a fish because of this.

While this may work for some people I personally would never do it and would never recommend it.  The risk-free way is to use the dechlorinator.

[artw]

Note the following anecdote is purely from my observations of my fishes over the last 3 years.[/b]  I have no web reference, proof, or scientific evidence of the following statement

"heavy breathing and pale coloring"

this is from high nitrites or nitrates and low oxygen content in the water.

[Sue]

you mention you keep african's, and loose the odd one after a water change this summer.
-I"ve found that some tanganyikan cichlids are not as tolerant of large water changes as others and its good to adjust the % changed downward if you have more delicate types of fish.
-Also durning the summer the chloramine levels are at their peak in our tap water,  (to prevent the warmer water growing bacteria), so don't skimp on dechlorinator this time of year.
-also its good idea to avoid doing a water change really soon after a big summer rainfall, as tap water will be lower quality

[Pickoff]

Unless my test kits are faulty, all my water parameters are well within acceptable ranges:  Ammonia=0, Nitrites=0, Nitrates<5, KH=9, PH=?.  I am having trouble matching the color of the PH, it seems to be somewhere between 8.0 and 8.3.   I have checked the parameters of my tap water and they are all normal for tap water.  I keep my water temperature between 78-80 degrees.

I use Big Al's brand of Chlorine and Chloramine remover with every water change.  I apply the doses (1mm/gal)recommended on the container as I am filling the tank.

I have used the same regime for tank maintenance for the last 8 months.  Why am I suddenly losing fish?  I thought water changes were neccessary mainly to remove nitrates.  My Nitrates are well under control.  I have added an aerating stone to increase the oxygen levels in the tank.   My substate is made up of large grain crushed coral.  I am assuming this allows water and oxygen to flow through it.

Can it be a form of ich which is not visible on the body of the fish?  I tried to examine the gills of the deceased fish, but I did not notice anything unusually.  Mind you, I wouldn't  know what would be unusual.

I appreciate your comments and suggestions and please don't take offense if I come accross as dismissive of your cmments.  I am just eager to resolve this mystery before another one of my fish begins to show the tell tale signs.

[artw]

well you know it could just simply be bad genetics.
we can't do everything right all the time you know.