Looking for holtfreter's solution substitute

It's not that easy for lots of new axie owner to find holtfreter's solution. I need to find the easy to find product that close enough ingredient to holtfreter's solution that can be found anywhere. So far sadly the closest thing I found in the regular pet store is aquarium salt. I know I know ,it's not the same, and some even argued that it shouldn't be use with axie at all ( for the long term exposure ) So what else is there that close enough?

Ambystoma Genetic Stock Center
You can only buy it here, at least I've not seen any other source for it. But you may not need it, do you have soft water or hard water? Because hard water doesn't really need the solution, it was developed to supplement soft water for Axolotls.
I think Eastern US has mostly soft water, so you could benefit from this solution, but you may want to make sure before wasting money on solution. You'll need to fill out an order form and actually Mail in a check, it's so old school I know. Wish they'd offer online ordering...

"Aquarium salt" (Sodium chloride or NaCl) is one of the main ingredients in Holtfreter's Solution.

Holtrefeter's
Solution

NaCl
KCl
CaCl2
NaHCO3

Axolotls - Requirements & Water Conditions in Captivity

In a pinch, just the salt will do, (I use canning salt since it's the exact same thing as aquarium salt, just less expensive) although I also add a bit of baking soda (Sodium bicarbonate) to raise and buffer the pH and KH.

Here is the recipe for Holtfreter's Solution, if you're interested:

"Modified 40% Holtfreter's Solution: in 44 gallons H2O (Indiana University Axolotl Colony) - for use with embryos, larvae, and adult Axolotls (Ambystoma mexicanum).
KCl (Potassium Chloride) 1 teaspoon
CaCl2 (Calcium Chloride) 2.5 teaspoons
MgSO4 x 7H2O (Hydrated Magnesium Sulfate) 2 tablespoons
NaCl (Sodium Chloride) 240 cubic centimeters (dry volume)

If my calculations are right that would be 16 tablespoons of salt. Note this is to be added to distilled water..."

Holtfreter's Solution : Freshwater


Unless you're using distilled water, reverse osmosis water, or have extremely soft water from the tap (very low in GH and KH), I would recommend starting with 20%, then testing your mineral and pH levels to see where that gets you.

I've used the following modified Holtfreter's solution for over two years with good results. I've also used this solution in higher concentrations to treat things like ascites and edema.

Modified Holtfreter’s 40% per liter

NaCl……………...1.38g
KCl………………. 0.02g
CaCl2……………. 0.04g
MgCl……………...0.08g
NaHCO3.....…......0.08g


I usually keep a 5000ml stock solution in the fridge.