Mystery of the dying fish

[easyian]

Ok hopefully you guys can help. I know we've all read these before but mine is boggling me. I had a 33 gal tank set up fro 8 months. I kept up on my maint every two weeks I did a 15% water change and watched my water parameters. unfortunately in one week four fish disappeared. I checked my water and found 0 Amm, 0 Nitrites, and 10 Nitrates. So i watched the tank for a week for signs of sick fish. No signs. Then another death. Watched again for a week.Nothing, In the meantime i decided to upgrade to a 90 gal tank. I set it up with my old gravel and decorations, added the filter element to my new filter and had to add my remaining stock, roughly about 30 inches of fish. That was three weeks ago. Yesterday i had another death and also today. I rechecked my water from a week ago and got these readings Amm 0, Nitrites 0, and nitrates 5. And no signs of sick fish. So as you can see I am baffled. If anyone has any ideas I would love to hear them.

P.S. once a week i supplement their flake food for frozen bloodworms

90 gal tank Planted tank
Rena Filstar XP3 canister filter
Temp 74 F
3 dalmatian mollys, 1 male guppy, 3 Cardinal tetras, 6 neon tetras, 3 endler guppys, 2 FW shrimp, 3 platys, 1 siamese algae eater remaining

 

[cindywindy]

Easyian,

You mentioned your tank maintenance of every two weeks, but what does that entail ? Are you careful to vacuum the substrate thoroughly with every water change to keep the tank free of any disease-causing bacteria ? Are you careful to rinse the filter media to keep it from accumulating detritus ? These are always key, in addition to your normal water changes, in order to keep harmful bacteria at bay.

You also mentioned that you supplement your fishes' diet with frozen bloodworm. Is there any way that this package of bloodworms managed to get thawed out before you put it in your freezer ? It is very important to keep frozen bloodworm frozen, as frozen/thawed/refrozen bloodworm has ample opportunity for bacterial growth that can be harmful to fish.

 

[Allivymar]

Just to be clear, the test results are from yesterday? Or last week? A lot can happen in a week; if you haven't tested your water yesterday or today I suggest doing that ASAP so we can rule that out for sure.

Secondly, what type of fish died? That may also be a clue. I'm guessing at least one was an SAE: what were the others?

 

[easyian]

The water test were done yesterday(sept 10) and the reading are those I posted. As for the maintenance I vacuum every time I change out the water(15%or at least a close guess) and rinse the filter element off in the water siphoned from the tank. The blood worms I cant be 100% sure of but they were frozen when i got them from the LFS and I live a stones throw away. They were immediately put in my freezer and I defrost the amount Iam going to feed to the fish. The fish i have lost are all three of my black mollies, 3 guppys 2 female 1 male and my pakistan loach.

 

[cindywindy]

Easyian,

Altho I doubt this is the cause of the deaths, are you aware that Mollies for the mostpart are brackish, not FW, fish ?

When you upgraded your tank to the 90g, did you add anyone new to your existing stock ?

 

[Allivymar]

Sure sounds like your water husbandry is great.

I thought maybe if it were mostly scaleless fish there might be a chemical issue as they tend to be more sensitive, but there doesn't seem to be a pattern.

Is there ANY sign of disease? Changes in behavior, breathing patterns, unusual markings of any sort? For some reason I'm thinking of bacterial disease, but can't quite put a finger on why.

Just to rule it out, check your tank temps a couple times a day; maybe the heater has gone wonky?

 

[easyian]

I was not aware that mollies are brackish fish but that doesn't really explain the guppys and the loach. The only new addition are the FW shrimp but that was after the initial deaths. I have been watching for disease and the only thing i noticed after the last death was one of my dalmatians was pumping his gills. I kept watch over him and rechecked the next morning and everything seemed normal. All the fish are acting normal and no signs of external disease. BTW after the initial deaths I added some melafix to try and nip it in the bud. As for the mollies being brackish i would need to add salt to the water wouldn't I? Would this be hard on my other stock?

 

[easyian]

I forgot to add that the heater is new when i bought the new tank. Its a Rena Cal top light 300W I payed very close attention to the temp when i first filled the tank to make sure it was working. It hasn't fluctuated even a degree. Just thinking could adding plant fertilizer affect the fish in any way. When i set up the new tank i added some to help the plants reroot.

 

[Allivymar]

Auuugggghhh. I hate mysteries.

Its possible it was the ferts; I've heard of people having die offs after using some fertilizers. Thing is, I'm guessing you've only used them once; shouldn't still be affecting the tank, and the deaths started prior...

Ok. On to more probing questions LOL

Are there any chemicals being used around the tank? Spray cleaners, nail products, new paint/carpets? Small children??

What chemicals do you usually use?

 

[easyian]

NO children whatsoever(unless you count me) Our house is relatively new(less than one year old but its hardwood in the room with the tank). My wife decided to paint the computer room a month ago but thats upstairs. When I clean the glass on the tank I spray the windex on the cloth not the glass. And I think my nails look best natural. I don't use any chemicals in the tank and the only thing I have added are Melafix, Plant Gro iron enriched Aquatic plant fert, and Jungle brand Start right water conditioner to remove chlorine and chloramine. I am pretty careful around the tank because I don't want to pollute the water so this is why it is so baffling. BTW thanks for all your help. The way you've been helping you would think this was one of your tanks.

 

[Allivymar]

LOL told you. I loathe mysteries! Plus, I love my fishies and figure anyone who posts on here MUST love em as much as I do *grin* so I'm more then willing to help!

The reason I asked about chemicals, is I've heard some pretty wild stories. On another forum, one guy related the story of his SW tank, and how almost every week he had fish deaths, although all parameters were fine.

Turns out on Tuesday evenings he'd go out with the guys. His wife would stay home and do her nails in front of the TV in the room with the tanks. Yep, the fish always died on a Tues nite...turns out the fumes from the nail products were killing em. I'm glad to see you're not painting your nails in front of the tank; I think we can rule that out LOL.

Its got to be chemical or disease; I'd say we've ruled out water parameters/temp, your chemical additives (melafix and start right wouldn't cause probs like this unless they were somehow contaminated; I don't know enough about plant ferts to say if thats the prob, but I believe you've only used it a short time and the deaths started prior?) and nail products completely. Its a long shot, but maybe there is something in the water supply? If you're on a public water supply, you can check here to see if anything has been reported: http://www.epa.gov/safewater/dwinfo.htm

 

[easyian]

Well I don't know whats going on I havn't had any deaths since I posed this topic. So I guess all i can do is keep an eye on things and hope no more die. I'm not going to add to my stock for a while until I'm sure everything is alright. Thank you for your help.
Is it a big deal that i have brackish water fish in a fw tank. Should i return my remaining mollies?

 

[Allivymar]

Good to hear! Although, this one is going to drive me nuts (I can't even imagine how frustrating this has been for you!).

Mollys really are happier with some salt. Might be time for another tank *smirk*

And you're very welcome

 

[easyian]

well i do have my 33 gal cycling right now

 

[Allivymar]

*giggles*

Welcome to MTS easyian. My name is Allivymar and I suffer from MTS too