Mollies wiggling in one corner of the tank (one specific corner)(pls help)

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sanchay

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PLS REFER TO THESE VIDEOS TO GET THE CONTEXT

This molly started wiggling like this...then all other mollies started wiggling(THE SAME CORNER!!)....then all of them started to die back to back without a sign (sudden deaths....just fine yesterday,..found dead today morning)....this happened like a few months back....and all my mollies died...

now i got another 2 pairs of molly (around a week) and they started wiggling in the same corner again and i am afraid that they would also die

tank dimensions LxBxH = 20x12x18 INCHES....tank well cycled....all the values of ammonia,nitrite and nitrate are well under control...ph at 7.2 (back then....and now too)

i dont this the plastic plants are the issue (i tried removing them...no difference)(the mollies did not act like this when i had them in a smaller tank-5Gallons)
 
Hmm, from what I can see on your vids, its not something that is undue cause for concern.

Looks like she has an irritation or something like that and rubs against rock or glass corner.

A couple of questions before going any further, you said -

all the values of ammonia,nitrite and nitrate are well under control...ph at 7.2

Can we please have exact numbers as this is very vague and not particularly helpful to determine what may be wrong, a large number of problems with fish and tank is down to poor water conditions or parameter issues.
So the more information we have in regards to ammonia, nitrite and nitrate levels, the better really.

What type of test kit do you use?

And do you add dechlorinator to the tap water when doing water changes?

How often do you do water changes and how much?

How did you cycle this tank and how long did it take?

When do the mollies show those 'wiggling symptoms'?
Just after a water change for example.

tank dimensions LxBxH = 20x12x18 INCHES

And lastly, your tank is a little on the small side for mollies really, they are an active fish species and do need a bit of swimming space, would recommend a minimum of a 3 feet length tank (36 inch)

Quite a few questions, but as mentioned earlier, the more information given, the better we can help pinpoint the issue, if any.
 
Hmm, from what I can see on your vids, its not something that is undue cause for concern.

Looks like she has an irritation or something like that and rubs against rock or glass corner.

A couple of questions before going any further, you said -



Can we please have exact numbers as this is very vague and not particularly helpful to determine what may be wrong, a large number of problems with fish and tank is down to poor water conditions or parameter issues.
So the more information we have in regards to ammonia, nitrite and nitrate levels, the better really.

What type of test kit do you use?

And do you add dechlorinator to the tap water when doing water changes?

How often do you do water changes and how much?

How did you cycle this tank and how long did it take?

When do the mollies show those 'wiggling symptoms'?
Just after a water change for example.



And lastly, your tank is a little on the small side for mollies really, they are an active fish species and do need a bit of swimming space, would recommend a minimum of a 3 feet length tank (36 inch)

Quite a few questions, but as mentioned earlier, the more information given, the better we can help pinpoint the issue, if any.
like it can be considered an irritation if they do it in the other corners as well....but its the same corner everytime...

i dont have a test kit...i give my water to the shop where i buy my aquarium products and they do the test for free...i do a test once in every 2 weeks or so...been a customer in that shop for an year...even when i had the smaller tank

i do not use tap water...i Use RO water with a TDS around 200-250....the water purifier does the dechlorination....the tap water in my area has really high TDS (around 1200ppm)

i do a 30% water change every 8 days with gravel vaccuming (sometimes extended to 10 days...but this is a rare case)

the tank is a well estalished tank (used for more than an year)

i let the tank cycle for a week initially

the wiggling is random....and very often....no specific time (initially athena started wiggling...then the others too started wiggling....THE SAME CORNER....she did not wiggle anywhere else....but that one corner)
 
Either they must like that particular corner or it has something that help the irritation like it may have more water flow or it may be a cooler corner, no idea at this stage to be honest.

Your tap water is at 1200ppm, wow, that is the highest TDS reading I have ever heard of, liquid rock essentially. Good you’re using ro water at 200-250 ppm TDS.

I would up the water changes from 30% to around 50% once a week rather than every 8 days if you can. The more clean water, the better the reduction in nitrates and less debris and poop swirling around. Gives better water quality and parameters.

When you go gravel cleans, ensure you don’t stir the gravel too much or too deeply as this can release toxins or disturbs the beneficial bacterias. A lighter gravel clean is considered safer and more beneficial imho.

The initial cycle a year ago of one week means tank definitely was not cycled at the time however it’s a moot point at this time since the tank and filter has been running for a year so it’s certainly established now.

Thats if you have not overly cleaned the filter or replaced the filter or anything like that recently.

Getting your own test kit if you can is good practice and enables you to test more often as well as giving you a much better idea of how your tank water parameters are on at least a weekly basis. Knowing the exact numbers for all ammonia, nitrite and nitrate will also give us a better overall idea of how good or bad the water quality is which may help explain why the mollies do this.

By the way, do you know what test kit your LFS normally uses and do you get specific readings from the LFS staff every time they test your tank water sample or do they simply say ‘water is fine’ kind of responses?

At the moment am still unsure why your mollies go to the same corner every time. Do they show any other symptoms at all like gasping, staying at water surface, lethargic or erratic swimming behaviour other than wiggling in that corner, red gills, clamped fins close to body or fading of colours etc

Habe you any other recent losses to any of your tank livestock?
 
Either they must like that particular corner or it has something that help the irritation like it may have more water flow or it may be a cooler corner, no idea at this stage to be honest.

Your tap water is at 1200ppm, wow, that is the highest TDS reading I have ever heard of, liquid rock essentially. Good you’re using ro water at 200-250 ppm TDS.

I would up the water changes from 30% to around 50% once a week rather than every 8 days if you can. The more clean water, the better the reduction in nitrates and less debris and poop swirling around. Gives better water quality and parameters.

When you go gravel cleans, ensure you don’t stir the gravel too much or too deeply as this can release toxins or disturbs the beneficial bacterias. A lighter gravel clean is considered safer and more beneficial imho.

The initial cycle a year ago of one week means tank definitely was not cycled at the time however it’s a moot point at this time since the tank and filter has been running for a year so it’s certainly established now.

Thats if you have not overly cleaned the filter or replaced the filter or anything like that recently.

Getting your own test kit if you can is good practice and enables you to test more often as well as giving you a much better idea of how your tank water parameters are on at least a weekly basis. Knowing the exact numbers for all ammonia, nitrite and nitrate will also give us a better overall idea of how good or bad the water quality is which may help explain why the mollies do this.

By the way, do you know what test kit your LFS normally uses and do you get specific readings from the LFS staff every time they test your tank water sample or do they simply say ‘water is fine’ kind of responses?

At the moment am still unsure why your mollies go to the same corner every time. Do they show any other symptoms at all like gasping, staying at water surface, lethargic or erratic swimming behaviour other than wiggling in that corner, red gills, clamped fins close to body or fading of colours etc

Habe you any other recent losses to any of your tank livestock?
yes...i just do a light gravel stir every time...maybe like 2 months once...i do it a little deep

nah...no filter change....would just wash my filter medium slightly with the water taken out during the water change

they tell me the values...i asked them and they told they use some API kit

yea...i could get one...but those API kits here are too pricey (around 60$....my tank costed 70$)

i did not see any kind of lethargic behaviour....but I have noticed that the males stay at the top half while the females prefer the lower half....they dont usually gasp...but when i see them i turn on both the filters in my tank (one does good filtrations...but the aeration is just enough...this filter is a large one and the one always running...while the other is a power filter which is small but doees a great job in aerating...)

they stop gasping after i turn on the power filter...also i have a plenty of plants and hiding spots

like the molly in the video actually passed away...the whole set of molly died...now i got mollies again and one of the molly is wiggling in that corner again
 
What is the GH of your RO water /tap water? It may be that the water is too soft for mollies and that is causing shimmying. In that case the tap water may be better for mollies.
With shubunkin in the tank (not recommended as they need cooler water), you will need to water change twice a week, at least 50%.
 
Is this the same aquarium that has the Rainbow in it that is acting strangely too?


The mix of fish...Mollies, Shubunkins and Rainbows....is, to be brutally honest...absolutely insane and even moreso with an aquarium that small

I am really not buying the water chemistry results being fine....the body twisting and shimmies is indicative to bad water chemistry, wrong water temperature and a poor choice of species mix imho.
 
Is this the same aquarium that has the Rainbow in it that is acting strangely too?


The mix of fish...Mollies, Shubunkins and Rainbows....is, to be brutally honest...absolutely insane and even moreso with an aquarium that small

I am really not buying the water chemistry results being fine....the body twisting and shimmies is indicative to bad water chemistry, wrong water temperature and a poor choice of species mix imho.
like i had mollies and the shubunkin in a smaller (i was a newbie back then) 5G tank and none of them acted weird...and yes this is the same tank...but the mollies which wiggled died like a few months back....i got the rainbows a month after the whole pack of 6 mollies died....the only remaining fish in the tank was one of the shubunkin...he was all alone for a month
 
What is the GH of your RO water /tap water? It may be that the water is too soft for mollies and that is causing shimmying. In that case the tap water may be better for mollies.
With shubunkin in the tank (not recommended as they need cooler water), you will need to water change twice a week, at least 50%.
i do a 30L water change every 8 days or so.....and my shubunkins are quite fine with these temps....they dont seem to have any kind of issue...never seen them acting weird or have a disease
 
What is the GH of your RO water /tap water? It may be that the water is too soft for mollies and that is causing shimmying. In that case the tap water may be better for mollies.
With shubunkin in the tank (not recommended as they need cooler water), you will need to water change twice a week, at least 50%.
i have no idea of the GH.....but when i first started being an aquarist...i cycled my 5G tank for around 2 weeks then started with 4 mollies.....and all of them died....i used tap water at the beginning....they died the next day i introduced them to the tank
 
i do a 30L water change every 8 days or so.....and my shubunkins are quite fine with these temps....they dont seem to have any kind of issue...never seen them acting weird or have a disease
They will be adding a lot of waste which adversely effects water quality, larger more frequent water changes would be much better.
The higher temperature will speed up their metabolism and shorten their lives, although I appreciate that you may not be able to provide a cold water environment in India.
 
i have no idea of the GH.....but when i first started being an aquarist...i cycled my 5G tank for around 2 weeks then started with 4 mollies.....and all of them died....i used tap water at the beginning....they died the next day i introduced them to the tank
The fact that they died almost immediately is more likely due to a misunderstanding of the cycling process than the water being an incorrect GH. I strongly recommend you find out the GH of your water sources as it is a very important aspect of fish care.
 
From a behavioural point of view, it looks like the fish is trying to escape the water it's in.
Why that particular corner? If you were in the tank, looking out at the world from that corner, what would you be seeing? A door? Window? Dark hole?

i dont this the plastic plants are the issue (i tried removing them...no difference)
Can you please tell us why you thought removing the plants might help?

For a cycled and established tank, it does look very, very clean.
There is something in the tank that is clearly fatal to mollies. Can I suggest you stop buying mollies, until you know what the issue is?
It would be interesting to review the health of the other fish, once there are no Mollies present.
 
From a behavioural point of view, it looks like the fish is trying to escape the water it's in.
Why that particular corner? If you were in the tank, looking out at the world from that corner, what would you be seeing? A door? Window? Dark hole?


Can you please tell us why you thought removing the plants might help?

For a cycled and established tank, it does look very, very clean.
There is something in the tank that is clearly fatal to mollies. Can I suggest you stop buying mollies, until you know what the issue is?
It would be interesting to review the health of the other fish, once there are no Mollies present.
from that corner my television would be visible...my whole living room will be visible....likr the place where my tank kept is surrounded by walls...the only side not covered is the front....

i had my older 5G tank in front of the TV...but then as we always had our hometheatre turned on...the bass were scaring them.....so i moved them to another spot in the living room (a dedicated spot for a fish tank where the bass does not affect the tank)...

so are they just bored?
 
Last edited:
From a behavioural point of view, it looks like the fish is trying to escape the water it's in.
Why that particular corner? If you were in the tank, looking out at the world from that corner, what would you be seeing? A door? Window? Dark hole?


Can you please tell us why you thought removing the plants might help?

For a cycled and established tank, it does look very, very clean.
There is something in the tank that is clearly fatal to mollies. Can I suggest you stop buying mollies, until you know what the issue is?
It would be interesting to review the health of the other fish, once there are no Mollies present.
i did not remove the live plants...i removed the artificial plants.....just to make sure that the plastic aint detoriating or the plants are hurting the fish
 

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