fish dying after water changes

[notoriousB]

Recently I've been losing fish immediately after water changes. First happened in January immediately after a 15 gallon change, lost my male clark's clown and my yellow tang. Thought they might have gotten in a fight, since the clarkii was a very aggressive fish, especially with a clutch of eggs present. Had both of them for 7 years.

2 water changes since then, same volume, no problems.

Yesterday I did another 15 gallon change and immediately afterward my big female clark's clown started breathing heavy and sitting at the bottom of the tank - this morning she's gone (can't find her, somewhere in the rock work) and my tiny yellow tailed damsel is dead on the bottom. I've had both of those fish for 9 years. Also can't see my Swissguard (had him for 7 years) although he hides a lot, so can't say for sure if he's missing or just hiding.

These fish were all long term residents, and have been through good and bad times in the tank, and even survived a move.

No new livestock has been introduced for well over a year. Remaining fish and all corals look OK, but we all know looks can be deceiving.

Just did water tests:
Sg = 1.025
Ph = 8.1/8.2 (between 8.0 and 8.3 on the chart)
dKH = 7.7
ammonia = 0
temp = 76

Same results after the two losses in January.

I'm baffled.

100 gallon display, 30 gallon sump (probably 10-12 gallons of water). Lots of water flow.

Any ideas on what the heck else I should look at would be appreciated. Thanks, B

 

[Dangger]

is 76 degrees too low for a tropical tank?

aside from that, perhaps it's getting temperature shock.. have you been preheating your new water before you dump it in?

 

[BrianMac]

assuming that you are not using tap water, did you try testing the water parameters with another test kit? Just a thought.

 

[notoriousB]

temp's been at 76 all winter. Yep, I preheat the water before changing.

I use RO/DI water for changes, new filters on the system last month. RO membrane is about 1 year old.

I tested the pH and dKH w/ 2 test kits, salifert and a cheapo tetra kit. I only have one ammonia test, it's relatively new but might be worth changing. I'll have to pull out my old swingarm hydrometer to verify the Sg, tested w/ a refractometer.

Thanks for the responses!

 

[jtmac]

First sorry for your losses. 2nd I suspect your ammonia kit is probably off. If you had all that death, there is no way your readings will come in at 0. The temp is ok I have mine at 76 in the mornings and climbs up to 80 during the day.

 

[JohnK]

How do you prepare your water change water other than heating it? How long does it sit? Is it being stirred when it sits? How long is it allowed to mix before doing the water change?

 

[MikeG]

Also do you always use the same pump and or heater for mixing water? Bad seal leaking toxins into the water? Any problems with inverts or corals? New batch of salt? Also waiting for a response on Johns question on how you prepare the water.

 

[notoriousB]

the ammonia kit was new in january, but I can certainly get another one. Ammonia doesn't make sense to me though, the affected fish are perfect until the water changes, then immediately afterward (overnight) they're gone. the other fish have not been affected (visibly) and between changes there have been no (visible) issues. And no losses for two months between these two events. My corals actually look GREAT right now too.

I'm wondering if there's something in my sump that's getting stirred up during water changes, I remove most of the water via the sump, leaving it very low, and then refill via the sump as well.

For water changes I fill the bucket w/ RODI, once it's full I run an 802 powerhead and a heater to bring the temperature up and to mix the water. I add salt initially to get it close (i can get it to roughly 1.020ish via measuring cup measurements), and once the temp is up I verify sg via refractometer and add salt as necessary to get it to the proper level. It sits at least overnight to get up to temp, and after I add salt to get the level up to 1.025 I always wait a while (few hours min) before testing then changing.

A small positive for the tank - I just saw my swissguard zipping around, so I didn't lose him! He's probably my favorite fish.

 

[notoriousB]

MikeG your reply snuck in while I was typing the above response - yes, always the same pump & heater. Maybe a bad seal, I don't think the Haigen Powerheads (model 802) are oil filled though?

Corals look really good. Not many inverts in the tank, but the hermits/snails I have in there have been there a very long time and seem fine.

It is a new bucket of salt, same vendor I have been using for over a year. Can't remember if I got this new bucket before the 1st event. I have done changes though with this same salt between these two "events" and there was no loss of fish.

 

[GobyWanKenobie]

Since you've had the same fish for 7 years, you're not exactly new at this. If you're doing the same procedure each time, maybe it's something out of your control. Even though you are using RO/DI is it possible your town or well water occasionally gets something in it that your RO/DI can't filter out? Maybe check with the water department and see if they did something different. Could something have contaminated your buckets? It's especially confusing that you have had successful water changes between the two "events". Definitely have to think "outside the box" on this one. Good luck. If you figure it out, let us know what it was.

 

[bossreef]

Maybe something with your new filters. Preservatives? Or maybe chloramines making your fresh ro/di water to have ammonia. Try testing the mixed water before the change?

Anything else change recently?

 

[The Ng Thing]

Since you've had the same fish for 7 years, you're not exactly new at this. If you're doing the same procedure each time, maybe it's something out of your control. Even though you are using RO/DI is it possible your town or well water occasionally gets something in it that your RO/DI can't filter out? Maybe check with the water department and see if they did something different. Could something have contaminated your buckets? It's especially confusing that you have had successful water changes between the two "events". Definitely have to think "outside the box" on this one. Good luck. If you figure it out, let us know what it was.

I was thinking the same thing.

 

[s_kelley]

A 15 gallon water change in a 100 gallon plus tank shouldn't be killing anything unless you are doing something drastically wrong. Like using ice cold tap water or something crazy. It soundslike you are doing everything the right way and it is just one of those things that happens.

 

[gweston]

Odd problem indeed. I'd suspect a heater/powerhead being used to heat and mix the fresh salt water. Maybe contamination somewhere. Really stinks you had all those losses.

 

[Neya]

+1 On above.
I had something similar happen with my fresh tanks waaaay back in the day. My filtration was not filtering out a contaminant or bacteria outbreak in city water. I ended up losing a huge portion of livestock although inverts and hardy fishes remained OK. This was a pure mystery until 2 years after when the details of the poor water quality for that period of time had been investigated and published. The whole time I was in contact with water supply but they kept reassuring me it wasn't them. Turns out I wasn't the only one complaining (Which started later investigation)

 

[notoriousB]

Since you've had the same fish for 7 years, you're not exactly new at this. If you're doing the same procedure each time, maybe it's something out of your control. Even though you are using RO/DI is it possible your town or well water occasionally gets something in it that your RO/DI can't filter out? Maybe check with the water department and see if they did something different. Could something have contaminated your buckets? It's especially confusing that you have had successful water changes between the two "events".

yeah this tank's been set up for 4.5 years now with no real changes, I haven't added ANYTHING for over a year, and aside from cleaning the skimmer and h2o changes there's been nothing done to it. It's really baffling. I'll have to call the water department to see if anything has changed. It's not well water, it's city service, from a reservoir I believe. I don't know what could have contaminated the buckets - I store them in my basement and they're covered while stored, with the pump/heater/tubing in the bucket. Don't do anything crazy in the basement either...

I've had the female clown and the yellow tail damsel since I first started keeping a reef tank, and they've survived things that probably should have killed them back when I was just learning and didn't know what the hell I was doing in this oft frustrating hobby.

Maybe something with your new filters. Preservatives? Or maybe chloramines making your fresh ro/di water to have ammonia. Try testing the mixed water before the change?

Anything else change recently?

The RODI filters were changed just a couple of weeks ago. The first "event" was with my old filters, this most recent with the new.

I did not try testing the mixed water before the change. I will definitely do that before my next water change.

No other changes at all recently.

I had something similar happen with my fresh tanks waaaay back in the day. My filtration was not filtering out a contaminant or bacteria outbreak in city water. I ended up losing a huge portion of livestock although inverts and hardy fishes remained OK. This was a pure mystery until 2 years after when the details of the poor water quality for that period of time had been investigated and published. The whole time I was in contact with water supply but they kept reassuring me it wasn't them. Turns out I wasn't the only one complaining (Which started later investigation)

ugh, that's a scary thought. Something like that could certainly be the culprit too... and way out of my control.

Odd problem indeed. I'd suspect a heater/powerhead being used to heat and mix the fresh salt water. Maybe contamination somewhere. Really stinks you had all those losses.

I can certainly change heater/powerhead for the next water changes. Is there any way to tell if there is an issue with a powerhead? It looks fine, I take it apart after each h2o change to let it dry out completely and haven't noticed anything out of the ordinary.

Thanks for all the input everyone. -B

 

[Neya]

I really hope what happened in my case is not the same for you. It was easier for me to figure out it was not from equipment as I had many separate tanks affected(including strict QT tanks). FWIW it happend to me in Maine, and not around MA.

On the heater/PH idea. Id certainly swap them out at least temporarily. I've had countless heaters fail me through the years without any signs of wear. I've also had heaters of the same make/models(my two faves were old ebo jagers and some titanium brand I cant find anymore) last me gosh... almost 10 years now? Long enough that the rubber suction cups disintegrated lol.
I dont know much about power heads though, Ive only just begun using them for SW. When in doubt on any equipment I always just do a temp swap to see if it helps.

 

[JohnK]

I'm wondering how long you spend on doing the water changes, and how much circulation the tank has? Thought being - if the tank has mild flow, and that flow is shut down for a while for the water change, could low O2 be the problem?

 

[notoriousB]

I'll definitely try different pump/heater when I do my next water change. The only thing I can think of if it were something in the water itself is wouldn't my other fish be affected too? After each change/deaths all the other fish still seem fine. After the first "event" the remaining clown seemed bummed out for a while but other than that seemed just fine. If there were something in the water I'd think it would affect everything else too.

John K, I have a ton of circulation, Mag 7 sump return, Mag 9.5 closed loop, and a dual powerhead rated (supposedly) at 3000 gph. When I do the water changes I have a battery backed air pump both on the tank and the sump that kick on automatically, those run until circulation is restarted. Usually I don't have the pump power off very long, 15-20 minutes maybe, tops. I've had power outages at my house that have lasted hours and the only circulation was the battery powered air pumps, and never lost anything during those times.

 

[JohnK]

Huh, Scratch the low O2 theory.

Any sandbed disturbance during the changes?