# live plant vs aquarium salt



## luckysarah (Nov 3, 2010)

hi there,

This is my first post but I have been reading a lot.

I haven't had fish for years but recently set up a 30 gallon for my kids, we let the tank cycle (used a product called cycle that worked fairly quickly).

We added live plants first, 2 java ferns and a bunch of other "easier" plants (can't remember exact names)

We have 3 mollies and 2 guppies as well as 3 blood fin tetras, I have been reading that these types of fish (mainly the mollies which I plan on getting more of since they are enjoyable) like aquarium salt added, not brackish but just the plain 1 tsp per 5 gallon aquarium salt.

i have also been reading that plants do not like the salt....

So my question is to salt or not to salt?


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## redchigh (Jan 20, 2010)

There is no reason to add salt.

What is your ph?

Black mollies like salt to prevent disease, but only because they have weak immune systems.


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## luckysarah (Nov 3, 2010)

Ph is at 7.4

and they are balloon mollies, not sure if that makes a difference but I have just been reading that livebearing fish prefer salt.


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## Byron (Mar 7, 2009)

Hi luckysarah, and welcome to Tropical Fish Keeping forum. Glad that you found us and have joined.

I have previously researched the issue of adding salt to a freshwater aquarium, and my findings will be cited below. There is scientific evidence that salt does not belong in a freshwater aquarium. Those who say (or write) that "livebearing fish prefer salt" are not strictly accurate. It would be correct to say that livebearers can tolerate salt, or manage with salt in the water; but they do not need it, and they are better off without it, as should be evident from what I will write below. And plants certainly do not need it, and many will wither for the reason I will now explain.

Salt is detrimental to freshwater fish and plants in varying degrees. To understand why, we must understand what salt does in water.

Salt makes the water more dense than the same water without salt. The aquarium contains water. The bodies of fish and plant leaves also contain water [just as we do--we are, what is it, 70-some percent water?]. The water in the aquarium and the water in the fish/plant are separated by a semi-permeable layer which is the cell. Water can pass through this cell. When either body of water is more dense, the other less-dense body of water will pass through the membrane to equalize the water on both sides.

Water is constantly passing through the cells of fish by osmosis in an attempt to equate the water inside the fish (which is more dense) with the water in the aquarium. Put another way, the aquarium water is diluting the fish's body water until they are equal. Freshwater fish regularly excrete this water through respiration and urination. This is the issue behind pH differences as well as salt and other substances. It increases the fish's work--the kidney is used in the case of salt--which also increases the fish's stress in order to maintain their internal stability. Also, the fish tends to produce more mucus especially in the gills; the reason now seems to be due to the irritant property of salt--the fish is trying to get away from it.

I have an interesting measurement for fish. Dr. Stanley Weitzman, who is Emeritus Research Scientist at the Department of Ichthyology of the Smithsonian Institute in Washington and an acknowledged authority on characoid fishes, writes that 100 ppm of salt is the maximum for characins, and there are several species that show considerable stress leading to death at 60 ppm. 100 ppm is equal to .38 of one gram of salt per gallon of water. One level teaspoon holds six grams of salt, so 1 tsp of salt per gallon equates to more than 15 times the tolerable amount. Livebearers have a higher tolerance (mollies sometimes exist in brackish water) so the salt may be safe for them.

Plants: when salt is added to the aquarium water, the water inside the plant cells is less dense so it escapes through the cells. The result is that the plant literally dries out, and will wilt. I've so far been unable to find a measurement of how much salt will be detrimental to plants; all authorities I have found do note that some species are more sensitive than others, and all recommend no salt in planted aquaria.

Now you know why I never recommend salt.


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## luckysarah (Nov 3, 2010)

Makes sense

looks like no salt is the better option, seems like lots of conflicting information out there. Even on the label of the fish at the pet store it said "requires salt" but of course they want to sell the salt so...... 

I think in the end the plants are more beneficial then anything so I will leave the tank alone.

thanks


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## seove (Sep 5, 2014)

This is a great article. Thanks for sharing. I will definitely reduce my reef salt from 1 Tbs / 10 gal. (on water changes) to 0.

This is off topic but I know someone who is doing research on acclimating plants to saltwater. The experiment involves guppies, mangrove trees, and algae. The oils from algae can be burned as fuel oil. The research is aimed towards finding plants that will grow near sea shores.



Byron said:


> Hi luckysarah, and welcome to Tropical Fish Keeping forum. Glad that you found us and have joined.
> 
> I have previously researched the issue of adding salt to a freshwater aquarium, and my findings will be cited below. There is scientific evidence that salt does not belong in a freshwater aquarium. Those who say (or write) that "livebearing fish prefer salt" are not strictly accurate. It would be correct to say that livebearers can tolerate salt, or manage with salt in the water; but they do not need it, and they are better off without it, as should be evident from what I will write below. And plants certainly do not need it, and many will wither for the reason I will now explain.
> 
> ...


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