Fish Dies after Water Changes

W

wcharon

Member
Hi...

I am concerned with my fish death after 10 gal. water changes. I have a 80 gal. reef tank with several fishes for a while. I have found that after my monthly wayer changes the last fish put in the tank dies, this time was a Sailfin Tang that was OK since 1 month.

My practice of water changes is prepare RO/DI water in a bucket for 24 hrs. aerated and then mix with a power head RC salt for 24 hrs. again. Leave 1 day with the power head off and then aerate for 2 hrs. prior replacement in the tank. Turn off tank return pump and siphon water from display tank and then power on and add prepared water thru the sump.

After 2 days salifin died, i have noticed that this is a practice that have been occuring me for a time ago with tangs, so thats why i assure is something in my wc practice.

Thanks for your advice...
 
Sorry, yes...

I always measure prepared water vs tank water prior with new salifert test (PH, Alkalinity, Nitrate, Nitrato, Amonia, TDS) including SG (1.026) with no additives.

I was reading of aeration depletion but my water change is only 10-15 min. with the return pump off.
 
Check your salinity ... most likely it was either that or you saltware you replaced was conataminated with something. Could something have accidently been poured into it while it was mixing?
 
For sure the salinity was matched 1.026 with refractometer. Yes it is the same container, but if it is the container contaminated why only happens to the last fish introduced ????? My yellow tang, rusty angel, blenny, blue hermits and corals are OK.

Seems funny.
 
When i introduce new fish after 1 month should i start making less amount of water changes for less stress (5 gal. instead of 10) ???
 
I would say to stick with the 10, thats only about 12%. water is up to temp?

Have you changed the filters and what not in your RO lately?

Regarding that the water is to temp, parameters are nice, and the filters are fairly new, it's the salt. Just my $.02
 
OK. My RO fillters are 6 months old but the TDS meter is reading .01 only. Well i have to accept that the temp is not equal because my tank temp is 77-78 and the other is 80. I thought that a diference of 2 degrees will not affect because the chiller will push it up fast...My chiller is a Aquatic 1/4.
 
I have heard you want your change water to be a few degrees COOLER than your tank. If your water temp in the "holding tank" for the changes is left in for 2 days, maybe biological growth of some kind(bad bacteria) and it is hitting newly added fish, because your older fish are "used" to this bacteria, as it was likely grown/cultured very slowly over the period of years building up in the "holding tank" so they have built a resilience towards it. If this is the case, the good bacteria in your tank probably kill the bad pretty quickly, and it is undetectable shortly after the change, which is why a fish that is added would not notice it when he was added, but when you did another change. Heck, it could be a few hour spike, might be enough. Good way to test it is get a new fish, acclimate and add to the tank(hate to use FISH to test, but it's probably a good test). Grab a cheapy 1-gallon tank and something for filtration/oxygen/flow. If you have a quarantine tank, could use this. Anything that can support the fish for 2-3 days that is COMPLETELY disconnected to the tank. Take him out and place in this facility. Use the "old" water to fill this receptacle. Then do the water change, 3 days later, re-acclimate and add fish to DT again. If all is well, you know it is something that corrects itself quickly, that your fish are adjusted to already, and the spike doesn't work for new fish.

Just an idea, I could easily be talking through my foot.(would have used a less pg term, but figured better off going pg-rated)
 
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Given your parameters of the new water and tank water are pretty much equal...it may be a stress issue. Did the sailfin look sick or stressed prior to the water change? What other fish do you have?
 
The problem is that you assume the water change killed your fish. Making these assumptions is a common mistake in this hobby.

It makes much more sense that something else killed your fish. Start listing your water parameters and think of other causes for the death of your sailfin tang.

Lets start over, how had the fish been looking/acting/eating before it died?
 
^^^ Only thing that strikes me is he says it is developing a "pattern" of ALWAYS doing it after a water-change. I want to say it is something in the water, either a type of bacteria, or something that his "aged" fish are used to already.
 
How frequent is "always" Last two times? Last ten? If it is two times, it may just be coincidence. If it is more than that I would look into another cause. I do have a hard time believing that a water change will kill one specific fish and not effect the rest in any way. I assume the rest of your fish are acting normal?
 
One other question that could perhaps be germane, is how many times has this happened? And is it every water change? And I'd agree with Logzor about how your fish were acting before the change. I would tend to doubt that the water change is responsible.
 
Wowwwww, thanks for all the responses. I will try to answer all of them...

Really and believe me, this pattern has been occuring me from the last year (12 times), thats why i say it's the water change, no coincidence. I bought a UV thinking sterilizing the water and same issue. The Sailfin was eating from my hand looking EXCELLENT and when i made the WC the next day was in a side of the tank and this morning was dead.

Chiefsurfer details sound like a possibilty in the lower degree of the WC. My actual fishes are Yellow Tang, Blenny, Rusty Angel, and corals. By the way, another pattern is when i get to the 4th. fish in teh tank, so probablly what says Chiefsurfer of the bacteria can be a possibility.
Regarding bacteria all my parameters are 0 with LR, WetDry without bioballs in it.
 
Sounds like stress. Are you purchasing all the "new" fish from the same place? Could be possible the latest fish added to the tank has territory near where the new water is entering tank? This could be causing some of the stress ...
 
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