Do Mollies Need Brackish Water

[fishguy2727]

No. Mollies found at the LFS are bred on the exact same fish farms as all the other freshwater fish found at the LFS.

In nature mollies do go in to brackish and even full marine for food under their own choice and for short periods of time. They are not there permanently.

Forcing a higher salinity on them can cause problems for them long term, they simply are not adapted to handle it.

Even if mollies did better with some marine salt, this would only matter if they were the only fish in the tank or all the other fish were brackish too. Adding salt to a freshwater tank with an assortment of fish in it because one of those fish is a molly is not a good idea at all.

Please read this article for more information:
Salt in a Freshwater Aquarium

 

[MBOU]

Depends on the exact species....

Personally, they survive in freshwater but hugely benefit from having low levels of salt run through the tank, even if not regularly, this will only mimic the fact that they do venture out towards the sea for food.

Also, i will NEVER keep black mollies without salt in the tank, so bloomin prone to health problems which just dont seem to crop up if salt is present.

A lot of LFS do run salt through livebearer tanks, easiest thing is to ask or if all livebearers are on one system, assume its because there are low levels of salt?

In the last shop we did, ran sg at about 1.008-1.011 depending on if we had new arrivals etc... sometimes we let it run with no salt but i did notice thqat problems with mollies were far more common when there was little or no salt...

I cycled a marine tank with Mollies once, they were so happy in there that we left them in there. Although before anyone got any ideas.... they were usd to low levels of salt anyway and it was increased over a week or two and then they were drip acclimatised so it wasnt a shock.

 

[fishguy2727]

IME as long as you provide high quality food and water you should not have any health problems come up. IME salt helping things tends to hint that something else is going on and the salt is an effective stress reliever like it can be in almost any tank.

Fish shops frequently run salt through the tanks of all types of fish as a stress reducer or to treat against certain things.

Like I said, the mollies commonly found in the hobby do not require salt to thrive. As stated, unless they are the only fish in the tank this is a moot point since the other freshwater fish certainly should not have salt added all the time.

 

[MBOU]

Exactly my point... salt is used on systems in shop to prevent the occurance of bacterial and fungal infections like the flexibacter in guppies... its not a cure, but it does prevent problems occuring before they do and mollies are fast going the way guppies are. Inbred, poorquality and weak immune systems. Doesnt matter where you buy them from, most breeders are doing the same thing.

 

[Fishy friend2]

Ok thanks for all the info, so I have come to a conclusion that they do not need it at all,

 

[three-fingers]

They are more sensitive then platies/swordtails/guppies in freshwater as domestic mollies are a hybrid of several wild species, some entirely fresh other more brackish/marine.

Some fish breeders in the far east breed them in brackish water before they arrive at the LFS, and some individuals/strains are just hardier and more adaptable than others.

So some "need" it more than others, based on your luck in choosing fish.

If your a newbie who has water quality issues, or an experienced aquarist with soft acidic water, then your mollies probably will "need" salt to live and thrive.

If you have hard alkaline water and perfect water conditions, then you don't, but they will benefit from it and aren't great for community tanks (males get large and aggressive) anyway so there's usually no reason not to add some marine salt.

 

[fish48]

Exactly my point... salt is used on systems in shop to prevent the occurance of bacterial and fungal infections like the flexibacter in guppies... its not a cure, but it does prevent problems occuring before they do and mollies are fast going the way guppies are. Inbred, poorquality and weak immune systems. Doesnt matter where you buy them from, most breeders are doing the same thing.

when keeping black mollies with out salt they do well kept at 78- 80f.

it is not true that all guppies are of poor quality and all have weak immune systems.
there are many lfs and good fish breeders with very good quality guppies.

 

[fishguy2727]

But treating them with salt temporarily in a shop where they are stressed from being shipped from farm to wholesaler to retail store recently is very different from adding salt all the time, especially at the recommended doses. Mollies can and should thrive without any salt at all. If you provide high quality food and water they will thrive without salt. If you do not provide high quality food and water then you probably will need to add salt, at least from time to time.

If soft water is the issue salt is not the answer. It is much more effective to just put some crushed coral in the filter like it is carbon. It will safely harden the water without imposing high salinities on the fish.

Yet again, it is very important to point out that none of this matters unless the only fish in the tank are mollies. If you have ANY other freshwater fish in the tank it should go without question that adding any type of salt all the time is not in the best interest of the fish.

 

[three-fingers]

If soft water is the issue salt is not the answer. It is much more effective to just put some crushed coral in the filter like it is carbon. It will safely harden the water without imposing high salinities on the fish.

With my experience of mollies in a soft water area, I would have to totally disagree. Marine salt provides far more natural elements than crushed coral and alters the water far, far more, faster too. It also kills off a lot of different bacteria and fungus which they may be carrying.

By saying "imposing", your implying that high salinities are harsh on the fish - quite the opposite, the domestic LFS molly will thrive and breed in full marine systems, and often look far larger healthier than their freshwater counterparts IME.

Crushed coral in the filter can help but if you have soft acidic water, you may need more than a little in your filter to improve your water stats for mollies. You would do well to use it as a substrate and use limestone rocks similar to a Mbuna set-up.

But why bother when platies, swrordtails and guppies are generally far more adaptable, and smaller and less aggressive when mature?

If you specifically want to keep mollies, low-end brackish water using marine salt is the perfect answer to keep them in best health and see them at their best IMO .

They very often do work in community tanks with hard, alkaline water, but they also often don't.

 

[Fishy friend2]

I was just wondering, because I was considering keeping them, but now I don't want to due to their size, and water conditions. I don't have hard water and I figured out that they can get up to 5 inches long

 

[fishguy2727]

IME crushed coral in the filter is much more effective than substrate and rocks because of the flow.

Do people at least agree that adding salt is only an issue if the mollies are the only fish? If there are any other freshwater fish adding salt is not the way to go.

 

[creeker]

IME crushed coral in the filter is much more effective than substrate and rocks because of the flow.

Do people at least agree that adding salt is only an issue if the mollies are the only fish? If there are any other freshwater fish adding salt is not the way to go.

I agree with that. I would never add salt in my tanks that contain tetras, cories, Rams, etc. I also would not add salt in my planted tank. If I were to keep a molly only tank though, I would add salt. Years ago, we used mollies to fish in cycle our saltwater tanks. The mollies kept in those tanks were bulletproof.

 

[MBOU]

Agreed, wasnt a debate for other fish, only mollies were being talked about in the poll

But i agree, i'd not want to put salt in with most other fish. Tell you one thing... discus do NOT like marine salt >.<

Had an oooooppsssy when swapping fish from one tank to another,took all day as was swapping marines into a smaller 250L and discus into the bigger 340L... meant putting fish and water into loads of buckets and barels and rmembering which ones salt and which isnt lol... then scrubbing the tanks...

I had the same eheim filter on both tanks so thought i would take a short cut, left the pipes and swapped the filters...

Got everything sorted and turned on the filters.... only for the discus to start going mental and scratching themselves and gasping and hiding as far away from the filter....

Forgot to empty all the pipework of salt water didnt i..... so after saving all that water and all the hard work... had to do a 90% water change on 340L as well!

 

[HayzH]

i have soft water with a ph of 7.5. My 3 mollies didnt do at all well.

 

[Roseanna]

I can't keep mollies at all due to soft water couldn't work out why the 4 I had one by one died ( black mollies 1st then spotted then yelllow) when my water stat's were good and they had no sign of ill health and all the other fish along with the glass cats are very healthy so I put it down to my ph being too low for them