Added powerhead, changed water, fish dying?

[Pat Niemeyer]

I have a three year old tank with many inhabitants that have been alive and healthy for nearly all that time. Three days ago I replaced the little in-tank oscillating powerhead that had overgrown with gunk with one of my old Rio 2100 powerheads, just for additional circulation. Now one of my fish is dead and another long time inhabitant seems to be dying. A couple of other fish and inverts seem ok.

The first fish seemed distressed the next day when I was changing the water. He kept coming (uncharacteristically) up to the top of the tnak... as if he needed oxygen. I was only changing 10 gallons of a 90g tank... so even if the water wasn't up to proper o2 levels or temp I doubt that could be it.

I removed the pump yesterday... just in case it was the cause. Today my yellow tang is hiding in corners and listles... he isn't eating... I'm pretty sure he's dying too.

Here are the only things I can think of -

1) The pump was stored in a plastic container with some water in it... It smelled bad. I ran it under fresh water for a few minutes before using it again, just to clean it out. Is it possible there is some toxic mold or bacteria growing in it?

2) a few months ago I switched from storing fresh water in my rubbermaid 30g trash can to storing salt water... I then transport it upstairs in 5g plastic jugs. This time I may have let it sit for a couple of days before using it... Anything wrong with storing salt water in plastic or rubber?

3) I stirred up a lot of cyano bacteria mats cleaning the tank when I introduced the new powerhead... Not much more than a normal cleaning, but the pump really cicrulated it.

I'm at a loss as to what to do now... bigger water change? Add a bunch of carbon?


Pat

[Pat Niemeyer]

I just wanted to add that my salinity, temp, and pH seem ok and two other fish seem fine.


Pat

[zedx6]

I am new to this but I think if the powerhead smelt bad possibly the mold is having an affect, I am sure someone with more experience will have an opinion.Good luck!

[mikenpam]

I would blame it on the added circulation kicking up the sand bed and releasing something that affected the fish into the water. I am new to this but have read where disturbing a sand bed (excessive) can release quite a bit of detrius, etc into the water. Especially as you stated that you kicked up cyano mats and my understanding is that cyano is an indicator of a problem in the first place.

There may be a possibility of stray voltage from the powerhead you just added and it could be affecting the fish.

I would recommend a major water change, 20 -25%, and remove the powerhead. I know circulation can help reduce your cyano problem so I would clean the pump really well or buy a new pump (way cheaper than relpacing fish.) It may also be good to clean the top layer of your substrate if possible; mechanically of with some natural detrius removesr such as hermits, etc.

One othe rpossibility is that the circulation stressed the fish and they had an oubreak of Ich. Were there any signs of white spots on their bodies? I think this is a small possibility as I think it takes awhile for Ich to kill a fish.

[Pat Niemeyer]

Thanks for the thoughts.

The bed is aragonite and I regularly vacuum it when changing the water. So it wasn't totally unusual to have detritus kicked up, but it was on the heavy side. I also blew out the rocks (as usual) with a turkey baster.

I did remove the pump and I'm just going to toss it out to be safe... though it was the main pump in there when I bought the tank years ago.

I was also wondering about temperature... I think my main pump is getting calcified and weakened (need to take it out and clean it when all is stable) - I wonder if there is a big temperarture gradient from the top of the water column to the bottom... and if possibly the new pump evened it out too fast? Seems unlikely...

Well, I'm going to do another water change and add a bunch of carbon.


Pat

[Pat Niemeyer]

So, it's been three days since I *removed* the new pump and my yellow tang is still acting like he's dying... He won't eat... He just seems stunned and listless. I can bump him with my finger and he barely tries to run away... very odd. The other two (remaining) fish seem fine...

Could spending a day with a big powerhead in the tank have so stressed out the fish that it killed one and scared one nearly to death? It's just a RIO 2100 powerhead... it didn't churn the water like a mixer or anything...

I finally put back the old oscillating one... for lack of anything better to try now...

I also ordered new filter cartridges for my RO/DI... I *just* replaced them a couple of weeks ago with a different brand and the water smells chlorine-y to me... It tests ok... but I don't know if that could be another varaible... I doubt it...

Changed 5 gallons more tonight when I cleaned out the filter area...


Pat

[Purple Haze]

dont forget, Rio's are notorious for melting down in tanks and killing off livestock.

Could it be possible something was introduced into the system by the new pump?

[Pat Niemeyer]

I'm going to follow up on this in another post because to see if anyone has any ideas, but... After watching the Tang for another day I am 99% sure that what is wrong with him is that he is now blind! He has become more active now, he just can't seem to see... he swims into things, doesn't flinch if I move at him or shine a bright light in his face, etc... I couldn't tell at first because I guess he was so freaked out that he just didn't move at all... now he's moving (he must be starving...) swimming around erratically.... especially when I put food in the tank.

The poor guy... What on earth could blind a fish (and kill the other smaller fish)? Could stray current from a bad pump do it? Is it something chemical from the new RO/DI filter?

I put a ton of carbon in and ordered new RO/DI filter cannisters... Of course I threw out the pump...


Pat