I read that exact site, but honestly I'm not convinced. Nowhere does it really say that the salt itself keeps them healthy, just that it prevents fungus or parasites, and if you have clean water and change it regularly that generally isn't a problem anyways.
"Marine salt mix contains table salt plus a huge variety of other mineral salts, including a large quantity of salts that raise pH and increase hardness. The addition of marine salt to molly aquarium provides mollies with water chemistry much closer to that which they prefer and also acts as a buffer, inhibiting any subsequent water chemistry changes. Tonic salt can’t do this, because it contains nothing by sodium chloride, a chemical that doesn’t modify pH or hardness at all. An aquarist adding a certain amount of salt to the molly aquarium is effectively guaranteeing the correct water conditions without any need to mess about with pH buffers or water hardening agents."
that's exactly what i'm talking about, the only REAL benefit IMO is that it's closer to their natural water parameters, but they can be acclimated to just about anything.
from a post on badmanstropicalfish.com
"To really get tot he bottom of this discussion
GH and KH numbers are needed,
TDS (Total dissolved solids) levels would be really handy but most aquarists don't have a TDS meter, and they really aren't that necessary.
Freshwater varies a lot in how much of what may be in the water.
In natural waters, Gh is primarily derived from Caclium carbonate, and
magnesium carbonate which is dissolved into the water as it flows. note that in both cases carbonate is part of the equation, Carbonate hardness (KH) buffers the water and increases pH. So in the Wild, water that is high pH is typically High Hardness levels. This created standard mindsets and practices concerning hardness and pH.
With municiple water supplies things get tinkered with. Initially caclium and magnesium were removed or reduced to facilitate soap sudsing (The same as a home water softener) This has evolved into a whole new process of removing anything that will cause buildup in water pipes, and then tampering with pH fixers to reduce corrosion in the pipes. So with municiple water supplies, We get oddball pH reading that have little to no bearing on the hardness of the water.
In a nutshell I can easily start with
RO water,adjust the hardness to 30 dGH (513
PPM) and maintain a pH of 6.8. I can take water with a KH of 7 and a natural pH of 8.0 and drive it down to pH 6.8 without changing anything in the hardness numbers. In addition to removing many things from the water, a lot of water companies use thing like
phosphate buffers to alter pH these buffers are short lived and really throw off readnings from tap. Suffice it to say that with any municiple water treatment nothing should be assumed. get a water report from their website and see what you are ctually ealing with. the standard norms and hobbyists test kits leave a lot of unanswered questions.
Now enter the rest of the TDS equation, and you add in all kinds of other solids that do not effect pH and do not effect our hardness tests. Fish don't read pH, they react directly to the amount of solids in the water, and the solids effect their osmoregulation (The process of internal pressure verses external pressure and the resulting transfer of water and nutrient in and out of their tissue)
SO while
calcium carbonate and magnesium carbonate may be the natural environment to the fish, they will respond similarly to other solids in the water. The downside to this is those other solids may carry long term side effects. Just like with our bodies, imbalances and too much of certain compounds and we see a reduction in health. There is very little salt content in Freshwater. Even the rift lakes which are considered by most to be the saltiest freshwater on earth have little salt. (Lake tang has the equvalent of roughly 1/4 teaspoon per gallon) so fish that live in freshwater do not have bodies or metabolisms designed to handle high levels of Sodium, or Chloride.
So (I'm probably rambling a bit too much) Mollies are naturally a hard water fish. If they are presented with softer water they will adapt, but not necessarily thrive as well as they would in hard water. As mentioned in the example in my original post, when someone adds salt, the molies improve. This is because the salt increases solids, and changes the Osmotic pressure to somethng closer to what the fish may prefer. This is something the fish feel that creates a reaction, and while the reaction may be positive it also comes with possible side effects. I always equate it to drinking alchohol, it relaxes you, makes you feel better, boosts your confidence and so on. but drink alchohol constantly for 5 years and see where you are at
With marine mixes you have a very high content of magnesium and calcium to go along with the Sodium and chloride. This makes brackish water more natural than soft freshwater or even salted freshwater, but is still not the ideal, or I guess a better way to say it is you still have unneeded additives that could cause problems.
Chloride in general is detrimental to a lot of things. Sodium is likewise hard on many organisms. Elevated levels of these two will essentially lead to the equivalent of renal failure in most fish. Salt interferes with normal Osmoregulation in freshwater fish. so a fish that has been exposed long term to water with drastically different densities than naturally found will not be able to properly regulate mineral and water content in their body. This will essentially weaken the fish slowly over time and make them more susceptable to disease and less likely to fight off disease. Mollies will see far less negative effect from salt than most freshwater fish. I've never kept a molly full life in brackish water so I don't know how much effect it has on mollies in particular.
In most cases the difference is Subtle, and therefore not noticed. With mollies in particular they have a very high tolreance to both sodium and Chloride. When we talk about mollies we are looking at a fish that can and will adapt and live in virtually any water, so We need to remember we are discussing ideal rather than necessary. Mollies do not "need" brackish water, and if you have a tank of mollies only, or a freshwater community then It wouldn't be advisable to give them brackish. If you have a Brackish tank and want to add mollies to the community, they will adapt and live fine. There is a far cry of difference between saying they "need" brackish and saying they will "live" in brackish. There is also a difference between acceptable healthy conditions and ideal conditions. In many cases we as hobbyists have learned that it is better to use what we ahve than to try to create ideal conditions. Stability is really the only requirement most fish have, and stability is easiest to achieve when our tanks parrameters match our tap water parrameters. In the case of this discussion, folks are going to the trouble to add marine mix for a fish that doesn't need it, thus they have more cost, more work, and in most cases less stability than they would have otherwise. It makes little sense to go throiugh this for a fish that doesn't really "need" it and actually may be better off without it.
I don't think I've ever said it was a bad practice to keep mollies in brackish tanks, But I will quickly say It's unnecessary, and should not be reccomended as the best solution to molly health and breeding issues. I will also add that I'd much rather see someone reccomend Brackish conditions than I would to see them reccomend adding "freshwater Aquarium salt" to the tank. Brackish is a far cry better and not even the same discussion in my book.
Many folks claim that Mollies are primarily brackish fish in the wild. All of the maps and population numbers I've ever found suggest that they are primarily Freshwater with a heavy brackish population as well. Either way both will work, but I still consider Mollies Frehswater fish that live in Brackish not the other way around. To add some confusion people also quote that mollies are primarily collected from brackish water. This may be true, but that doesn't mean that they spent most of their lives in brackish, they migrate and move from fresh to brackish to salt and back, The collection numbers may simply be based on the easiest place to intercept them with a net. No one wants to walk 10 miles of ditchline to collect a fish that can be easily found where the creek dumps into the ocean. It also makes one wonder about the population numbers and origin overall. Since they migrate, where did those brackish fish really come from. are they only there for a summer vacation, do they live there 10 months out of the year? Did they get lost and stay there because they couldn't find their way home? Some attention is paid to migration patterns and numbers, but not enough to get us a full picture by any means.
Now for the crux (See I can eventually get to the point ) Whatever our tap nay bring in as freshwater, we need to know what we have, and then decide if we want to alter it, or simply get the fish to adapt to what we have. in most cases the fish can adapt easily enough, but some of us like to fix our water to optimize things for certain animals.
In your particular case, I'd hazard a guess at pretty soft tap water, or possibly tap water that is devoid of one particular necessary element. My experince with the shimmies is that calcium defeciency is more often than not the cause. You can have water that tests hard on a gh kit and still has no calcium in it. My tap water comes with a calcium level of 40ppm and a magnesium level of 4 ppm. You can reverse those numers and get the same hardness reading.
You marine salt mix is wll balanced in all essential earth metals and minerals (Sounds like a commercial doesn't it) so wahtever the defeciancy that created the shimmies, the marine mix suplied it and the fish improved. That doesn't mean that all of the other things in the marine mix were needed, it only means that what was need was in fact in the mix somewhere.
In my case I raise GH (Calcium and magnesium) for my snails and shrimp. I raise Kh so I can iject large quantities of Co2 for my plants and still not dive into the lower pH numbers. The fish are required by me to live with what I have, And honestly my Rams do extremely well in that hard water and so do my mollies of course. My cories and Ottos breed frequenttly (Rams are still small but I expect they'll breed as well)
Our GH number indicates (In most cases) Calcium and magnesium levels
Our KH indicates Carbonate buffer and directly correlates to pH unless we are injecting CO2.
Since we know mollies like something akin to natural hard water we can take our base line GH and KH and adjust them up to whatever we want our mollies to have. In my case I have other reasons to increase these levels, so I've never really looked at how much is the right amount, I just know my mollies love my hardened water. I add Crushed coral, aragonite, and in some cases baking soda to elevate my KH to about 5-6
DKH (sometimes astronomically higher). Remember that baking soda will not increase GH so if you happen to use it, you aren't doing as much for the mollies.
I keep my GH at roughly 15-20 dGH . I add calcium to achieve 100-120 ppm calcium and add magnesium at a ratio of 1-4 on caclium. in other words Calcium at 120, magnesium at 30 ppm.
For calcium, I use Caclium Sulphate I buy from Gregg watson
For magnesium I use epsom salts (Magnesium sulphate) I buy at the local big box or drug store.
Note that Epsom Salts is pure Magnesium Sulfate, no sodium, no chloride.
Both are easy to dose, and will raise the GH in a very natural way that will benefit most fish. I don't use anything with sodium or Chloride (Especially chloride) if I can help it. The baking soda does contain sodium, but I seldom need it, and when I do it's for short term quick adjustments not chronic use.
At one time I used Caclium Chloride regularly to increase calcium, but found it had adverse effects on my plants, and didn't wait to see what it would do to my snails shrimp and fish.
All in all If you have a molly only tank, I would never reccomend Brackish but would reccomend finding out what your Calcium and magnesium levels are and elevate them if they are low.
I will also say I've kept mollies very well in soft water, but they did not breed well in those conditions. And despite being pretty soft water it did maintain both caclium and magnesium, so it wasn't devoid of either primary earth metal
The best palce to find out how much of what to dose would be via the fertilizer calculators on most plant sites. if you can't find or don't know of a useful one, let me know and I'll search out some old links for you.
IF you want to just put something in the tank to keep it hard without dosing or calculating, just use crushed coral or aragonite in your substrate (Any of the typical rift lake cichlid substrates will work as well)
Aragonite and crushed coral are primarily caclium carbonate, and will increas both Kh and GH. As the pH increase the rate they dissolve at decreases, so they will top out and remain steady at a point. The mollies will really like that point from what Ive seen in my tank."
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