Saltwater Platys?

Question
QUESTION: I have a 29 gallon tank that I have had running for over 9 years. I the past I have had goldfish in it, but recently my last goldfish died. My son decided he wanted to try something different and so we purchase 4 platys. The man at the pet store said we should add aquarium salt to our platy tank, but I haven't read anything more about that anywhere. Is he right and how much and how should I add it?



ANSWER: Hi Page,
It is best to add aquarium salt to a tank, but this always depends on the fish you have, or intend keeping.  It helps fish with stress, and parasites.  Add 3 teaspoons of diluted aquarium salt to your water, and keep adding with each water change.  When you remove 25% of your water, add salt according to the water you remove.
Lynda

---------- FOLLOW-UP ----------

QUESTION: Thank you Lynda. You say it is best to add salt to a tank. I also have a 65 gallon freshwater tank with tetras and danios it it. Should I be adding salt to it too? Also, one of the difficulties I have had with both tanks is a relatively low pH. The water always ends up at a pH of around 6.0 within a day or two after adding pH down or alkaline tap water. Will adding salt to it help and why does the pH always drop?

Answer
Hi!
I would not recommend salt with Tetras.  They live in a low PH, and soft water.  It is best not to use salt with these fish.
Never use PH "up," or PH "down" to your tank water.  This makes the water fluctuate which is very bad for fish.  These products are really no good, and should never be used.  Adding PH down will bring down your PH, but it will bounce right back up in a day or two.  PH Up will bring your PH up, but it will go back down again.  These products are actually very dangerous to use.
Tetras and danios should live in a 6.5 to 7.0 PH.  To do this, if your PH is too low, buy a little bag of crushed coral at you pet store.  Wash the coral well.  Buy a pair of white nylons, and put 1 tablespoons of coral into the nylons making a little bag.  Put the bag into your filter so that water is flowing through it.  The next day, check your PH, if it is still too low, add another tablespoon, wait 24 hours, check your water again, and if it is still too low, add another tablespoon, and so on until you reach the right PH.  This must be done very slowly, as bringing up the PH too fast could be deadly to fish.  The best level to reach for you tetras would be 6.8, and your Platys 7.2.  Platys can tolerate a higher PH.
Make sure that you have no trace of the chemical PH down in your tank before trying to adjust your water.  Do a 25% water change.
I hope this helps.
Lynda

Hi Again,
You are very welcome...These products that they sell, most are deadly to fish.
Just one more thing...I forgot to mention..Keep the little bags of coral in your filter all the time, so that your water will always have the right PH.   You do not need to change the coral, it will always be good, until the little bag gets really dirty.  Then you could change the coral for new coral or just change the nylon bag..