Fish dying!

[Heyoka]

I have a 29 US gallon tank that is about 2 months old. 6 weeks ago, I got 9 harlequin rasbora. I used the silent cycling method where I added lots of plants to absorb ammonia. I closely monitored ammonia levels, which never got past .5 ppm (that happened once, and I promptly did a water change).

Everything was going great and my tank was fully cycled at last. Then, last week, an oto catfish died. I did some research and found out about the horrible use of cyanide to capture these fish in the wild (had I known this beforehand, I wouldn't have purchased them!) so I brushed it off as complications from that. But yesterday I woke up to find one of my rasbora looking rather pale and twitching. Several hours later, it died, and last night another rasbora started exhibiting the same behavior.

I did some water testing and ammonia/nitrites were 0. Nitrates were 15-20 ppm. To be safe, I did a 15% water change last night and another 15% change this morning. It seemed to work for a little bit but then they started acting oddly again. One seems obsessed with swimming against the current created by the filter. Another one was doing barrel rolls. I believe the one doing barrel rolls was the one I just found dead.

I'm kind of stumped here. My current ammonia/nitrites are 0 and nitrate is 10 ppm. Recent changes: Two weeks ago I changed the substrate and added a rock I found in the yard (which I scrubbed clean without chemicals). Last week I added a few plants. Yesterday I added another clean rock from the yard and put in some java moss, which I tied to the rocks with sewing thread. I don't know what kind of rocks these are, but they don't appear to be anything harmful.

Other inhabitants: 2 platies, 1 oto catfish, 6 cory cats, 2 amano shrimp, 3 platy fry

Please help! I hate seeing these fish die and I don't know what I'm doing wrong. I'm worried that I purchased these fish too early because I'm doing some reading and found that they are more sensitive than I thought. All my levels were fine when I was cycling though, and they seemed fine up until yesterday!

 

[absolutangel04]

Barrel rolls? Is it whirling disease?

 

[Heyoka]

I don't see any skeletal deformities. The second fish that began twitching seemed instantly okay once I did my water change, so I thought I was out of the clear and just needed to watch nitrate levels more closely. The barrel rolling seems to be a new symptom, and only the one did it. :/

 

[absolutangel04]

It seems like you have a pretty good grasp of tank maintenance, so I am not totally sure what the issue is here. What sort of dechlorinator do you use?

 

[Heyoka]

It seems like you have a pretty good grasp of tank maintenance, so I am not totally sure what the issue is here. What sort of dechlorinator do you use?

Aqueon water conditioner.

Something that it might be is my filter is really dirty. I feel silly for this but it just occurred to me to check it today. X_x I am going to buy a replacement tomorrow but could a dirty filter be the cause of this? Last I had checked it was maybe 2-3 weeks ago, and of course it's much dirtier now.

 

[absolutangel04]

The filter is where a lot of the beneficial bacteria live. I actually don't suggest changing it unless it is literally falling apart. Just swish it around in some old tank water and put it back in.

Any chance of a contaminant from rocks or something?

 

[Heyoka]

Hmm okay, I'll make sure to do that soon. The rocks are from my mom's house. The lawn care guys left them on her driveway and she has no idea where they came from. To be honest I have no idea what the lawn company does for her but I guess there's a chance there's fertilizer or pesticide on them. I scrubbed them pretty well but I didn't think of that possibility. Would it take a week for that to affect fish? I hope that's not the problem since I like how they look!

 

[foster53]

Hmm okay, I'll make sure to do that soon. The rocks are from my mom's house. The lawn care guys left them on her driveway and she has no idea where they came from. To be honest I have no idea what the lawn company does for her but I guess there's a chance there's fertilizer or pesticide on them. I scrubbed them pretty well but I didn't think of that possibility. Would it take a week for that to affect fish? I hope that's not the problem since I like how they look!

Possibly the rocks are your source of the problem. Try taking the rocks out, and using some carbon in your filter for a bit. The rocks could possibly have a poisonous substace on them.

 

[absolutangel04]

I think it's not too likely, but maybe a possibility. You could try taking them out, doing a big pwc, and see if the behavior continues.
And yes, contaminants can affect things awhile after introduction.

 

[Heyoka]

Alright, I took them out but can't do a water change until tomorrow night (I work Sundays and really should be sleeping right now). The rasboras look okay but aren't shoaling together like they normally do. Tomorrow I'll ask my mom about the possibility of chemicals on the rocks. I'll keep you guys posted. Thanks!

 

[absolutangel04]

Sounds good. Keep checking back here too because I am sure somebody else will chime in if they have a different idea or better advise.

 

[Heyoka]

My mom said there's no chance of the rocks having chemicals on them. She said the lawn care men were digging up a plant and found them underground (not sure how I got the idea that they just appeared on the driveway, lol). They didn't spray anything that day.

The only thing I could think of is I used a scrub brush that I didn't think ever had chemicals on it, but last night I realized I had. It was once, months ago, though, just to clean a spot on the floor. Would that really have done this? I'm beginning to wonder if I just have a bad batch of fish.

 

[librarygirl]

It's possible but not probable. To be safe you could do a large water change (50%+), use some extra dechlorinator and remove the rocks. Also what do you feed and how often? How long have you had the fish before they started dying?

 

[Heyoka]

It's possible but not probable. To be safe you could do a large water change (50%+), use some extra dechlorinator and remove the rocks. Also what do you feed and how often? How long have you had the fish before they started dying?

If it's not likely the rocks, will a 50% water change really do any good? A 50% water change will take me at least an hour to do, and for an extremely slim possibility, it seems like it's not worth my time. I have had the fish for 6 weeks and none of the other fish in the tank appear affected right now. I read a couple of cases online where a harlequin population simply died for no apparent reason, and someone described the same odd twitching behavior I saw. I'm almost positive this is just a breeding issue, or maybe some obscure disease that affects rasbora. The cory cats, platies, shrimp, and oto are all fine :/ I don't know. If this all happened on a day I was off, I would simply do the water change, but it's tough to get pumped up for something that might not even work after working 8 hours on your feet.

 

[Heyoka]

An update: I have been losing Harlequins left and right. I began with 9, from the same store, and lost a few on a weekly basis. However, their deaths became more frequent, and eventually I began losing one every 1-2 days. I was down to 3 yesterday before I was finally able to make it up to a different fish store for more (knowing, obviously, that 3 is not enough, but I had dropped from 6 to 3 in a matter of days). When I came home from the store, another had passed, so I was down to 2.

I bought 10 more Harlequins, bringing me up to a total of 12. Everything looked good, and I have been counting heads very frequently. I've been home all day, monitoring the fish, so I know they have all been swimming around happily. But just now, I noticed one of the Harlequins on the bottom of the tank, paralyzed. He is still breathing, but isn't moving. I even took him out, thinking he was dead, and only could tell he was alive by miniscule mouth motions. He wasn't flopping around in the air or anything. This will make EIGHT dead Harlequins in the past few weeks.

I'm very frustrated. I ended up removing the rocks even though I'm 99% sure they have nothing to do with this, and like I suspected, this has not stopped the deaths. I have other fish in the tank (currently 1 adult platy, 3 two month old platy fry, 6 cory cats, 1 oto catfish, and 3 amano shrimp), but none are dying like this. I did lose a female platy last week, though. She was from the same store as my original rasboras, and I honestly am not sure what she had, but I think it may have been fish TB. She became deformed with a curved spine, sunken in belly, and during the last few hours, she wasn't able to swim straight.

The thing is that I have no idea at all why these Harelquins are dying. I have not witnessed the twitching behavior that I mentioned earlier; now they don't appear to have anything wrong with them, but suddenly turn up dead. Like I said, I have been monitoring the tank all day, and I didn't notice any behaving oddly. My fear is that it's something that will affect my new Harlequins, too.

I just did a water change the other day, my parameters are good. Last check was a couple of days ago: ammonia and nitrites were 0 and nitrates were 10. I don't have the GH/KH testing kit but I ordered it today since that's the only thing I could possibly think of that I could test for that I'm missing. I feed them every 1-2 days. I switch up frozen and flakes (frozen blood worms or brine shrimp, TetraMin flakes, and algae wafers for the cats/shrimp/platies).

Just a refresher, changes that were made before my Harlequins started dying:

Added rocks found underground in the backyard
Added 3 emerald green cory cats (from the same store as my original rasboras and the platies)
Switched substrate from plain gravel to gravel + Seachem Flourite mixture
Added a few plants (java moss, which I have since removed; Italian val)

These changes were made pretty close to one another. I had the Harlequins for maybe 4 weeks before they started dying. I was told this means that it wasn't anything that the fish store did, but I question that. No one seems to be able to tell me what's going on. To make things even weirder, the Harlequins have laid eggs TWICE since I got them. The most recent time was a few days ago, when I still had 6 left.

Any ideas at all are welcome. I'm beginning to get very frustrated and discouraged.

 

[foster53]

Rasboras, and most other small fish can be susseptible to a bacterial disease called Saprolegnia. it exibits some of the symptoms you are describing. Not saying this is the problem but a possibility. Research this disease and see what you think. It is most common in Neons, and Cardinals, but affects other fish as well. Just a suggestion based on past experience.

 

[Heyoka]

Google says that fish display a white cottony growth. If that's true, it's not what this is. All 8 dead fish have looked completely normal. I've inspected each one after death and there are no physical signs of disease, other than a slight pallor on a few of them. But, I believe that's due to having been dead for a period of time, and not related to the cause of death.

 

[foster53]

It also invades the gills. Did they display rapid or irradic breathing. Or did the flash on objects in the aquarium like they were trying to dislodge something from the gill area? Might never know with out a necropsy, or autopsy. Just relaying an experience I had several years ago. Lost a complete tank of Neons, cardinals, and smaller Rasboras. It turned out to be Sap., never displayed the cottony growth thats what threw me off

 

[Heyoka]

Nope, I haven't noticed anything like that

 

[Heyoka]

So, two more died today alone. I am now down to 9. When I woke up, one was swimming back and forth along the surface of the water, again and again, and died within 10 minutes. And when I got home from work today, another had died. No evidence of any fungus or anything on the gills. The one that died this morning was very thin. He was one that I got 2 days ago, and I had thought he was just a juvenile. Maybe an internal parasite?

I am VERY frustrated at this point. I have lost 10 rasbora, and the ones that are remaining aren't schooling together. A few are eating, but most ignore whatever I put in. A big change from just a few days ago when I got them and they were swimming happily.

Any ideas?! I'm getting desperate. I'm really sick of finding dead fish every single day.