Why do my platies and swordtails always die?

[mrV]

provides the electrolytes that fish require to get to peak coloration and vitality.

Electrolytes increase electric conductivity, which increases osmotic pressure. Fish adjustes all time ionic-composition in bodyfluid and when osmotic pressure in water is lower than osmotic pressure in fish cells, water "flows" from emvironment to fish and fish has to get rid of excessive water. Most important organs are kidneys and gills (gills takes ions from water, if needed, and release them to water if needed). It takes lot of energy to keep osmotic pressure "steady" with environment.

So, adding chemicals to water without knowing "how much?" and "should I add?", it's always bad for fishes. If you really want to add some "salts" and you know, you need to add, you really should buy a conductivity meter (e.g. from Hanna Instrument). Then you know, how much you need to add someting - or is your water fine already!

My tap water is somewhat hard, but I do put in the water conditioner, so maybe I'm softening it up too much.

Probably your tank water is then hard too. How much do you add this "aquarium salt"? Could it change osmotic pressure so much, that new fishes don't tolerate it? How hard is your water exactly? It would be very good to ask water values from your LFS (from that tank where is those fishes you are going to buy) and compare them to values of your tank. If difference is huge, it could explain why those fishes die so quickly.

How big is your tank and how much do you change water? (Do you add more water, if it has evaporated from tank?)

 

[Stacey269]

I change about 25% of the water once a month and vacuum with a gravel vac. I do add water when the level gets low, but always when I change or add water, I add water conditioner to soften it up. I know that my water is hard because it leaves those white deposits on equipment, including my sinks at home. My other fish are all fine. Swordtails and Platies are especially sensitive to this?

 

[mrV]

change about 25% of the water once a month

You should do it once a week. And when you add water to your tank when water has evaporated, hardness increases in your tank; water evaporates but those ions, that cause hardness (or electric conductivity) stay in your tank. So, your tank water may be much harder than your tap-water.

Start to do water changes weekly.

I add water conditioner to soften it up.

I don't know any product that lower hardness. Are you sure, that you don't mean conditioners that remove chlorine, chloramines etc. from your water (e.g. Tetra Aquasafe...)

You really should test hardness (GH, KH) before you add any new fishes. And because you add some salt too, electric conductivity in your tank may be quite high. Fishes that you have now, they have been used to harder/higher el-conductivity water during months and probably it's shock to new fishes.

Swordtails and Platies are especially sensitive to this?

No, I don't think so. I think that water in your tank is quite different than those new fishes are accommodated. So, check hardness of water from your tank and do water changes weekly. Probably it is better that you don't annd that salt either, because you don't know how it affects on your water.

How hard is your tap water and how hard is water in your tank?

 

[Nina7777]

Hi ALL-

Just wanted to put a little caution in here about the aquarium salt, since it seems it has been mentioned ALOT!

Not all fish can have salt in their water.....even a little tiny bit will harm them. So if you have any species of catfish including plecs, please DO NOT add salt as they will most certainly die from it!

sorry had to mention it! As i wasn't warned before adding salt to my tank a few years back!

 

[rykitten]

Actually, don't many species of catfish like salt???

I found several links when I was researching white tip shark catfish, of which I now have 2. Here are a few links stating they like brackish water (small amounts of salt.)

white tip catfish

columbian shark

 

[Nina7777]

some do, but not most of the ones you find in LFS...such as cories, plecs, CAE and SAE to name a few, cannot tolerate even a small amount. That is why it is important to research fish before you buy them.

But hey i am no marine biologist, this is just what i read and from my own personal experiences.

 

[justupgraded15]

I have had salt in my water for a long time with 4 corys and plecos in there and they are happier thatn ever. Aquarium salt does not harm catfish. Salts like Instant Ocean and Red Sea would harm them, but aquarium salt is different. It does not add salinity to the water.

 

[Bol]

It does not add salinity to the water.

I'm not exactly sure what you mean by "salinity", but your salt does contain sodium chloride. From AP:

Aquarium Salt contains no artificial additives, sugar and, unlike table salt, no artificial color. It is made from evaporated sea water, which contains the following beneficial electrolytes needed by freshwater fish: calcium chloride, magnesium chloride, magnesium sulfate, potassium chloride, and sodium chloride.

 

[justupgraded15]

What I mean here is that it is a different form that cannot be measured in density. What is with this garbage about salt harming scaleless fish anyway. I don't men to sound disgruntled or anything, but it seems as if there is a split between salt users and non salt users. I had a fisheries biologist that has been keeping all types of fish for 30 years that I should have salt in the water even with scaleless fish. I believe that there is a misunderstanding here over the type of salt I am refering to.
J.R.