Mollys Keep Dying

[RumAndRedbull]

I'm a relatively experienced fish keeper, however in the past year I have moved into a new home out of state and haven't kept fish up until the past month.

It's a small, fairly basic setup, however, I have mollys. It's my first time keeping livebearers other than guppies, but since I've gotten them from this new fish store, they have been dying one by one everyday.

I've checked the water parameters daily, but non of the other fish seem to be effected by them either. (As well as they are all in safe range)

So I assume parasites, since all the mollys came from the same tank. Probably should have quarantined first...Here is an image if a spot I found. Thoughts?

 

[Byron]

First, always provide the actual numbers for any tests or parameters so we know. I've no idea what "safe range" means. And the GH first, and pH second, are crucial for mollies even moreso than other livebearers.

Second, ammonia may well be an issue here, as mollies are particularly sensitive to ammonia above zero, as well as to nitrite (above zero) and nitrates.

There may also be an issue with the mollies themselves, as you mention, but knowing the parameters (especially GH and pH) and the results of tests for the nitrogen forms will tell us something.

 

[RumAndRedbull]

First, always provide the actual numbers for any tests or parameters so we know. I've no idea what "safe range" means. And the GH first, and pH second, are crucial for mollies even moreso than other livebearers.

Second, ammonia may well be an issue here, as mollies are particularly sensitive to ammonia above zero, as well as to nitrite (above zero) and nitrates.

There may also be an issue with the mollies themselves, as you mention, but knowing the parameters (especially GH and pH) and the results of tests for the nitrogen forms will tell us something.

I use test straps so I don't have exact numbers, but I know mollies aren't particularly demanding.

Didn't think about ammonia, I still have yet to get straps for those. However, I figured if nitrites were down, it would be safe to assume ammonia is down, too.

pH - 5.5 to 6
gH - 75 to 90 ppm

 

[Alice B]

I use test straps so I don't have exact numbers, but I know mollies aren't particularly demanding.

Didn't think about ammonia, I still have yet to get straps for those. However, I figured if nitrites were down, it would be safe to assume ammonia is down, too.

pH - 5.5 to 6
gH - 75 to 90 ppm

Mollies want a pH of at least 7.5. Water change with higher ph water?

 

[RumAndRedbull]

Mollies want a pH of at least 7.5. Water change with higher ph water?

Probably a good idea...relatively new to livebearers, mostly only have kept koi, bettas, and arowana in my days haha

 

[Alice B]

bring pH up slowly. 50% water change, maybe another one tomorrow?

 

[speakerman3]

What were the mollies acting like at the store and after you brought them home. Were they shimmying with clamped fins? I put mollies in my tank as its first occupants--after cycling the tank--but I looked at five different tanks of fish before finding some that looked healthy enough to buy.

 

[RumAndRedbull]

What were the mollies acting like at the store and after you brought them home. Were they shimmying with clamped fins? I put mollies in my tank as its first occupants--after cycling the tank--but I looked at five different tanks of fish before finding some that looked healthy enough to buy.

I honestly couldn't tell you, I examined them but they seemed fine, only to understand a little stress due to the high occupancy of the tank they were in..

 

[Essjay]

gH - 75 to 90 ppm

This is far too soft for mollies. But soft water like this should not kill them fast, I would for another cause, but be aware that they will eventually become sick and die in soft water regardless of other issues.

 

[Slaphppy7]

The paper test strips can be inaccurate and unreliable, especially if aged; get one of these, ASAP: https://apifishcare.com/product/freshwater-master-test-kit

Run the tests for ammonia, nitrIte, and nitrAte, and post the results here.

ANY amount of nitrIte is deadly to fish...and if you have nitrItes, you have ammonia

 

[Byron]

@Essjay is bang on here. The issue is the GH of the water, it is way too soft for mollies (and livebearers in general, just so you know). The pH is a secondary issue because it is tied to the GH, and the mollies absolutely must have hardish water because that is the source of the calcium they require. Do not mess with the pH. For one thing, it will not rise unless you increase the GH and KH proportionally, the three parameters are interconnected.

The soft water will slowly kill the mollies, guaranteeed. The ammonia issue is another possible problem, but we have no test numbers so can't say. But the GH/pH problem is a killer here regardless.

And mollies aree one of the most sensitive fish to keep in an aquarium. They are highly susceptible to the parameters (GH, pH) and any form of nitrogen (ammonia, nitrite, nitrate).

 

[emeraldking]

For fancy bred mollies a pH of 7,2 and higher is preferred. A range of wild molly species are okay in softer water. Specifically the ones with a short dorsal. A Ph of 7,2 is okay for short finned fancy bred mollies. But those mollies with a higher dorsal need 7,5 or higher. So, a Ph of 7,5 would still be okay for your molly. I keep and breed mollies for some decades now and it should be okay. If you keep high dorsal mollies in softer water, their fins will start to tear. And they'll be more vulnerable for ich. Which can make them weaker and if you kept them too long in soft water, they'll eventually die.
So, not all mollies need hard water. But again, if you have a sailfin molly (Poecilia latipiina, Poecilia velifera or a Poecilia shenops with a high dorsal), it needs hard water. But a pH of 7,5 won't hurt by any means...