Sudden zebra danio deaths

[jfritz42]

Hi all,

I just had 2 of my 4 zebra danios die very quickly after a water change, and I was wondering if anyone had thoughts as to why.

What I did was siphon 30% of my water using a Python. Then I replaced it with tap water at the same temp as the aquarium (about 77 deg F). Immediately after that, I added about 2ml of Seachem Prime to neutralize the chloramine from the tap water.

A minute or so after adding the Prime, I noticed two of my zebra danios were doing loop-de-loops and they were dead within minutes. The other two zebra danios were fine! And I also have about 20 other fish (various species) and they were all fine as well.

My theory is that the zebras gulped some of the Prime before it could diffuse into the aquarium.

This is a 55gal tank that has been setup for about 2 months. I did the larger water change because I haven't been doing frequent smaller water changes and I was trying to address some of my plants getting brown/black leaves (thought the issue might be iron phosphate).

BTW, the water parameters were all pretty good before the water change. PH is 6.8, ammonia is 0, nitrite is 0, and nitrate is 10ppm.

Thanks,
Jason

 

[somecallmedaniel16]

your theory seems to be the only plausible idea. If the parameters were very close to their original before the pwc, then I don't know what else it could be. Hopefully someone will have more insight than me on this.

 

[jfritz42]

Thanks, Dan. Do you know how people normally treat chlorine when they fill the tank via a hose, e.g. a Python? I don't see any better way than to pour the Prime into the top of the tank after filling it.
- Jason

 

[EscVelocity]

You could pour it into your filter outflow, for better dispersal, or dilute it prior to adding it into your tank.

 

[Zagz]

I add the prime right at the beginning of refilling the tank with my python. I have 13 active tanks and have had for over 6 years and no problems whatsoever. Remember to treat for the entire tank volume, not just the volume replaced.

So sorry for your losses.

 

[spoonman]

I do the same. As its filling I just kind of pour it along the length of the tank. And I also treat for the whole tank, even if its just as little as 20-30% PWC.

 

[sieski]

I do the same. As its filling I just kind of pour it along the length of the tank. And I also treat for the whole tank, even if its just as little as 20-30% PWC.

I fill my tanks during PWCS by buckets. I treat the water in the bucket, stir it up. Should I treat just the volume of water being replaced or should I add extra after buckets are added to make up to tank volume based on a few people saying above treat the tank volume albeit for using a hose to fill up.

 

[mfdrookie516]

water conditioner is supposed to be added for the volume of the aquarium. for instance, when i do a water change in my 30g, no matter how much i change (20%, 50%, 75%, etc) i put the same amount, 15ml in. If im not mistaken, the majority of water conditioners require 5ml for every 10 gallons, so for a 55g, you should be adding 25-30ml of water conditioner. Now, as for you sieski, i dont know lol... ive never used buckets, so im not sure if youre supposed to treat the whole tank or just the buckets, but im sure somebody else will have an opinion on that

 

[jfritz42]

Hi everybody,

Thanks a lot for all the responses!

I forgot to mention in the original post that I did pour the water conditioner (Prime) along the top of the tank. And since it was only 2ml (about enough to treat 20 gal), I'm really surprised if this is what caused my zebra danios to die! But I have a hard time thinking of another explanation about what happened to them. It seemed like they went into some type of shock. And remember, it was only 2 of 4 danios that were affected, and also all other fish were fine!

Oh well, hope it doesn't happen again I plan to do weekly 10% water changes from now on.

Thanks,
Jason

 

[mfdrookie516]

if im thinking right, my prime says use 5ml for every 10 gallons, which would mean you need to use 10ml for a 20g.... if youre only putting in 2ml which would treat about 4 gallons, that could possibly be a contributing factor

 

[somecallmedaniel16]

sorry, looks like other people don't really know what the causes were. but just for good measure I'd follow their advice on adding the prime, just in case. but hey, at least danios are really cheap! sorry for your losses.

 

[jfritz42]

if im thinking right, my prime says use 5ml for every 10 gallons, which would mean you need to use 10ml for a 20g.... if youre only putting in 2ml which would treat about 4 gallons, that could possibly be a contributing factor

My bottle of Prime says that 5ml (one capful) treats 50 gallons. Maybe there's different concentrations in different bottles, I don't know...

You guys were right that the Prime instructions say to treat the whole volume of the tank if adding directly to the tank (i.e. not pre-treating a bucket of water). Still, that means I was under treating the tank and the danios died. Maybe they died of the chloramine...

Sorry, I don't mean to make this sound like a traumatic experience I just want to make sure I don't kill more fish.

Cya,
Jason

 

[jfritz42]

Hi all,

My fish killing saga continues!

This time I made a dwarf gourami and a nearly full grown angel get sick and die 4 days later. Again, I suspect it has something to do with a water change.

- I changed 30% water
- I had to leave the tank w/ 30% water gone and no filtration for about an hour due to an emergency
- I came back, filled with tap water w/ Python
- Existing water temp was 75F, so I used warm water in filling. Temp was about 79F after filled
- I diluted 1 capful (5ml) of Prime in a 16oz cup of water, then added to top of tank. Again, my bottle says 5ml treats 50 gallons (I have a 55 gal tank)
- I also added a dose of Leaf Zone (iron + potassium) for my plants. I added this directly to top of tank, not diluted

Later on, the gourami and the angel stopped eating. They hid for 4 days until dying.

All other fish are fine! The two surviving zebra danios from my last incident are ok. I have another dwarf gourami and another angel that were both perfectly fine. I also have 20 or so other small fish that were fine.

Ammonia 0, Nitrite 0, Nitrate about 30ppm before water change.

Any new ideas?
The Prime was somewhat diluted this time. Should I dilute more? Was it the water temp? Was it the stress of 30% water change with me waving the Python around? Was it the undiluted Leaf Zone?

Just trying to learn I don't like casualties...

Thanks,
Jason

 

[sieski]

Hi all,

My fish killing saga continues!

This time I made a dwarf gourami and a nearly full grown angel get sick and die 4 days later. Again, I suspect it has something to do with a water change.

- I changed 30% water
- I had to leave the tank w/ 30% water gone and no filtration for about an hour due to an emergency
- I came back, filled with tap water w/ Python
- Existing water temp was 75F, so I used warm water in filling. Temp was about 79F after filled
- I diluted 1 capful (5ml) of Prime in a 16oz cup of water, then added to top of tank. Again, my bottle says 5ml treats 50 gallons (I have a 55 gal tank)
- I also added a dose of Leaf Zone (iron + potassium) for my plants. I added this directly to top of tank, not diluted

Later on, the gourami and the angel stopped eating. They hid for 4 days until dying.

All other fish are fine! The two surviving zebra danios from my last incident are ok. I have another dwarf gourami and another angel that were both perfectly fine. I also have 20 or so other small fish that were fine.

Ammonia 0, Nitrite 0, Nitrate about 30ppm before water change.

Any new ideas?
The Prime was somewhat diluted this time. Should I dilute more? Was it the water temp? Was it the stress of 30% water change with me waving the Python around? Was it the undiluted Leaf Zone?

Just trying to learn I don't like casualties...

Thanks,
Jason

My water conditioner says
5ml treats 10g for chlorine removal
10m treats 10g for chloramine removal

That is nutrafin aqua plus

I used another brand a while ago which was every similar. These things are very standard. I match the temperature to within on degree. 4 degrees in a few minutes can/could be fatal.

I also fill via bucket and treat in the bucket stirred and left to settle for a minute. Least I know the water going is is treated and therre is no in between period of untreated water meets fish.

I would seriously try to find out if that is a mis print on your instructions. If not chuck it away and try another brand. I've been doing this for 4 months and only lost a clown loach and a honey gourami (which was murdered by a betta lol). Those are my guidelines above that I obey to.

also the angel and the gourami are far more sensitive to these rapid changes than other fish. The rule of "the others were fine" doesn't really apply. I reckon you could chuck mollies from a heated tank to cold tap water and they would survive easily, other fish wouldn't

what's your tank ph and tap water ph? have you had your water tested at a shop incase your kit is not working?

 

[WhiskeyD]

- Existing water temp was 75F, so I used warm water in filling. Temp was about 79F after filled

This could be your problem. A drastic change in temperature like that can definitely kill your fish. When I first started keeping fish I lost one fish from doing a PWC and the water i added back was about 3 degree cooler than the tank. I have also lost a fish from adding water that was too warm . I now match the water temperature at the faucet with a digital thermometer to the tank temp before I switch my python to fill. I have to recheck the water temp every minute or two when i first start filling to make sure the temp doesn't change (that's how i lost the fish from too warm of water). Good luck!

 

[mfdrookie516]

I lost 2 zebra danios the other day after doing a water change as well. Im thinking they may be very sensitive to chlorine... that is the only thing i can figure because i had the temp perfect... I always run hot water through the faucet first for a few minutes to make sure that its good and hot so that i dont set the temp one way, then the hot water start coming and warm up the water going in to the tank... if that makes sense lol. Oh and i got a big bottle of prime and it does say 5ml for every 50g of water, so i guess there are different concentrations. Hmm... If i were you, i would try using the python to remove the water, then use a bucket to fill it so you can pre-treat the water... Thats the only thing i can think of. All the other fish in my tank did fine, as well as the ones in all the others. Im guessing danios are just super sensitive to chlorine

 

[cabezon]

My concern is that you are adding the water then the prime. Also, do you have a special concentrated Prime? because as others have said, all the ones I have ever used put one cap full at 10 gallons. If you have chloromine, it is worse. and requires more. With a 30% change, all that chlorine, I am thinking you are killing your beneficial bacteria and having an ammonia spike.

I had that happen to my tank twice. Now I set out 20 gallons in the sun for a day, then add the prime.

 

[jfritz42]

do you have a special concentrated Prime? because as others have said, all the ones I have ever used put one cap full at 10 gallons.

I guess Seachem must have changed their concentration at some point, because I've seen this comment from several other people too. My bottle of Prime says exactly what the Seachem Prime website says (Seachem. Prime), which I quote here:

Use 1 capful (5 mL) for each 200 L (50 gallons*) of new water. This removes approximately 1 mg/L ammonia, 4 mg/L chloramine, or 5 mg/L chlorine. For smaller doses, please note each cap thread is approx. 1 mL. May be added to aquarium directly, but better if added to new water first. If adding directly to aquarium, base dose on aquarium volume.

Regarding your comment about chloramine:

If you have chloromine, it is worse. and requires more. With a 30% change, all that chlorine, I am thinking you are killing your beneficial bacteria and having an ammonia spike.

Yes, I have max 3.7ppm of chloramine in my water supply, which is 3.7mg/L. The Prime quote above says it handles up to 4mg/L of chloramine. It also says on that website that Prime breaks chloramine down in to chlorine and ammonia, then neutralizes both. I understand your point about the chloramine maybe killing my beneficial bacteria before adding the Prime, but I don't think this is happening because my ammonia and nitrite levels are always zero (although I haven't tested for a few weeks).

Anyway, thanks for all the advice from everyone. Sounds like it's either the water temp or the chloramine the fish are exposed to before I add the Prime. I guess I should start using a bucket to fill, which is unfortunate because it's a lot more work than just filling with the Python.

So nobody thinks the Leaf Zone could be the culprit?

BTW, my Ph is about 6.6-6.7, with water supply at about 7.2. I guess it's normal for Ph to drop over time?

 

[cwt]

I would first ask how old the danios were... I've had older ones that dropped dead without warning. Otherwise, I'd vote for the temperature answer. When I fill (with a bucket) I let the treated water sit a bit, so that it's close to the tank temp. Hope the die-offs stop soon.