Thought I wasn't a newbie anymore... but fishes keep dying :(

[Pisces girl]

Hi, happy new year!

I have a 55 gallon tank. Have had it for about 8 months. After initial problems with cycling etc and great help from this forum I thought I had it all sorted. Water levels were good and fishes seemed happy. Had a guppy male who was my favorite and he was gorgeous. And a few guppy females, neon tetras, lemon tetras and some platies. Also a couple of small plecos and cories. Now all are dead except the tetras. Every time I test the water though the levels seem fine. Ammonia is zero and nitrates/nitrites are always low. The only thing is that PH and buffering are quite low, but it has always been that way. Temp is around 75. I don't use a heater anymore as I live in FL and water temp stays steady. I used to change the water every week but I have been lazy/busy and only changed it every other. However, when I test the water before change, the levels are still fine so I thought it was ok. (Bearing in mind the LFS says that monthly water changes are ok, lol)

What could be killing my fish? I got some more guppies about a month ago and now they are all dead too. I really can't understand what it is. Does anyone please have any suggestions?

Thank you so much.

 

[Thyra]

Exactly what is your nitrite reading?? Any amount of nitrite can be deadly. Nitrates are okay at about 20-30ppm. Are you using well water or are you dechlorinating city water? Also are you trying to changed the pH because that in its self can cause a lot of stress to fish. How many fish to you actually have in the tank?

 

[Pisces girl]

Thanks for replying! I just tested again, ammonia & nitrite are zero. I think I meant to say that nitrates are low, way less than 20. I'm using tap water and I dechlorinate it. Same as I always did, back when fishes seemed healthy. I did try to change pH a few times a while ago but it was only a lame effort with a few drops here and there. Won't do that again. I don't have that many fish in the tank. When the last guppies came I had about 15 small fish in a 55 gallon tank.

When the fishes died most of them just stopped eating and hung out at the surface and didn't want to swim around anymore. Then I found them dead. Not all at once, at different times.

 

[FishDad]

Any new decor in the tank that could potentially be leaching?

 

[FishDad]

Or something that fell in that you can't see. For instance my three year old son likes to try to put pennies in my tank because we through them in the fountains at the mall. Maybe empty everything out to make sure nothing like that happened.

 

[Pisces girl]

You mean that things like that could poison the fish? Well we have a big ornament (that we always had) that keeps losing its paint. Maybe the paint is toxic... I will consider taking it out and replacing it with some big plant(s) maybe.

 

[FishDad]

That is a likely culprit. Is it meant for aquariums?

 

[CAPSLOCK]

Flaking decor sounds like a likely culprit to me as well - could be that the fish are just eating chunks of paint off it, even if the paint itself isn't leaching anything.

A few other thoughts:
-Is there good water movement in the tank, so that it is oxygenated enough? (I doubt this would be the problem but you never know)
-Is it possible your water company added some junk to your water supply?
-Sometimes those plants from Petsmart and such have a fun chunk of metal to anchor them - any of those in there?
-Have you used anything to clean the tank itself or right near the tank? Windex is deadly if it gets in there...'
-It's not getting TOO warm, is it?

I had at one point (still have, actually - not in use) a tank that we call "the death tank" because everything we put in there died. It was a used tank, not sure if there was something used on / in it that poisoned everything. But fish would be fine for a little while and then just die, no apparent reasons, various types of fish, etc. Was the tank used prior to you getting it? It would seem strange for this to be a reason since the neons are fine, but maybe they have some kind of immunity...

 

[Pisces girl]

Yes the ornament is meant for aquariums but I read reviews of it saying that the paint comes off so it's not just me. It's a big round "roman columns" thing. I guess the guppies are nipping at algea on the ornament and maybe they get paint into them too...

Metal on plants yes! And this is something I didn't have before so could this be a culprit? Metal poisoning??

No not too warm. Water movement seems good and this has not changed from when my fishes were fine for a long time. Junk in water I doubt it but you never know. Windex etc no.

Death tank lol... that's almost what it seems like now. But it was fine before after initial newbie problems (we had it from new), so something must have changed. I'm taking out the metal right now.