Molly fish laying at the bottom of the tank

[MatthewW]

Is your tap water treated with chlorine or chloramine

No

 

[Slaphppy7]

OK, well make getting that test kit a priority...and try to find the Prime...order online if you must

 

[Byron]

Given your info that only the mollies (all of them by the sound of it) are dying, and not the soft water fish, this may well be a GH issue. GH refers to the general hardness of water, which is the amount of dissolved calcium and magnesium in the source water from your tap. I doubt you have a test for GH, and you don't really need one if you have suitable water naturally. Check the web site of your water authority and see if they post data including the GH. General or total hardness are the usual terms. There is also carbonate hardness sometimes called alkalinity, expressed as a number with KH instead of GH, or the terms themselves. And then there is pH. All of these are worth knowing.

You should have a pH test though as this can be a very important guide to trouble now or down the road.

When we know the numbers esp for GH and pH, we will probably have the solution. While salt can help mollies, it will harm the soft water fish mentioned, so before going too far down that road, let's sort out the GH. If the water is too soft for mollies, no amount of salt will help them, they need the hard mineral.

 

[MatthewW]

Given your info that only the mollies (all of them by the sound of it) are dying, and not the soft water fish, this may well be a GH issue. GH refers to the general hardness of water, which is the amount of dissolved calcium and magnesium in the source water from your tap. I doubt you have a test for GH, and you don't really need one if you have suitable water naturally. Check the web site of your water authority and see if they post data including the GH. General or total hardness are the usual terms. There is also carbonate hardness sometimes called alkalinity, expressed as a number with KH instead of GH, or the terms themselves. And then there is pH. All of these are worth knowing.

You should have a pH test though as this can be a very important guide to trouble now or down the road.

When we know the numbers esp for GH and pH, we will probably have the solution. While salt can help mollies, it will harm the soft water fish mentioned, so before going too far down that road, let's sort out the GH. If the water is too soft for mollies, no amount of salt will help them, they need the hard mineral.

According to my research the hardness of the water is around 71 mg/l which i don't know honestly if that's okay for the fish
And ph 8

 

[MatthewW]

Just to point out the mollies are moving around more lately but tend to lay at the bottom again . Not sure if they are just sleeping or what

 

[Byron]

According to my research the hardness of the water is around 71 mg/l which i don't know honestly if that's okay for the fish
And ph 8

No, this is a serious issue, and the molies cannot live through this for long. From my profile:

Water Parameters: Medium hard to hard (12-30 dGH), basic (pH 7.5 to 8.5), temperature 21-28C/70-82F. This fish cannot survive healthily in soft or acidic water. Many sources recommend brackish water, though in its habitat the fish generally prefers freshwater, and the commercially raised fish have not been raised in brackish water but fresh. The black strain will be healthier at the warmer end of the temperature range, and most sources recommend brackish water, but the real issue is the “hard” minerals like calcium and magnesium, so harder water is better than salt.

A GH of 71 ppm [ppm is the same measure as mg/l] equates to 4 dGH. This is soft water, and only soft water fish species will be suited. The pH itself is OK, but the mineral content (represented by the GH) is the crucial factor for freshwater fish.

 

[MatthewW]

No, this is a serious issue, and the molies cannot live through this for long. From my profile:

Water Parameters: Medium hard to hard (12-30 dGH), basic (pH 7.5 to 8.5), temperature 21-28C/70-82F. This fish cannot survive healthily in soft or acidic water. Many sources recommend brackish water, though in its habitat the fish generally prefers freshwater, and the commercially raised fish have not been raised in brackish water but fresh. The black strain will be healthier at the warmer end of the temperature range, and most sources recommend brackish water, but the real issue is the “hard” minerals like calcium and magnesium, so harder water is better than salt.

A GH of 71 ppm [ppm is the same measure as mg/l] equates to 4 dGH. This is soft water, and only soft water fish species will be suited. The pH itself is OK, but the mineral content (represented by the GH) is the crucial factor for freshwater fish.

Ok in that case what should i do . I honestly have no idea the cause of them laying down(because of the hardness of the water or something else)as now they swimming around way more and are definitely healthier than before

 

[Byron]

Ok in that case what should i do . I honestly have no idea the cause of them laying down(because of the hardness of the water or something else)as now they swimming around way more and are definitely healthier than before

We cannot tell you what to do, that is your call, but from everything you have posted here so far it leaves no doubt in my mind that the soft water is the issue. Having fish requiring hard water in with fish requiring/preferring soft water always creates this problem, one of them is not going to be happy [= healthy]. The mollies seem to be weakening while the other fish seem from your info to be fine, so the mollies would be the fish to remove.

 

[MatthewW]

We cannot tell you what to do, that is your call, but from everything you have posted here so far it leaves no doubt in my mind that the soft water is the issue. Having fish requiring hard water in with fish requiring/preferring soft water always creates this problem, one of them is not going to be happy [= healthy]. The mollies seem to be weakening while the other fish seem from your info to be fine, so the mollies would be the fish to remove.

Ok thanks alot