This is about $10 and much more work. But easy.
Get a bag of plain Epsom Salts plain no oils fragrances, etc.
Epsom Salts is magnesium sulfate not table salt, sodium chloride. Also a key ingredient in keeping pH stable and raising GH
. And plants like it.
And ALWAYS treat any water you plan to use for fish, shrimp or snails before use whether I mention or not, for Chlorine/Chloramines/heavy metals and
ALWAYS use at the tank temp matched water for critter safety if adding to the tank!!!
Let's do a 5G bucket if you have that / easier to figure the amounts. I am not the best math expert
*Test tap water KH
for a baseline number
*then use 1/4 tsp (1/4 dose) of the Kent's Marine powder - mix well
(1 tsp for 20G)
*wait an hour or 2 test KH
see where you are in the test amount
Or if it seems far off target KH
Dump the bucket rinse and do it again double or use the full 1 tsp which would be (times 4 in 20 G of aquarium water).
It's late I hope this makes sense.
You want to figure out how much Kent's to add to be at the KH
you would like to have.
When you get that figured out write it down! Save the KH
water to add the Epsom Salts.
Now Epsom Salts / ES.
Use your KH
In a 1 gallon container mix a cup or 2 of hot water (you can microwave the cup or 2 of water to make hot) with a teaspoon of ES till dissolved, a few grains left is fine - fill to the gallon level
then if far off from your goal, dump that rinse, and try 1 tablespoon and test mixing with the hot water to dissolve. Fill to the gallon level.
See where you are at with GH
Adjust to try again and repeat, rinse and new amount of ES and repeat if needed to get to an ideal amount.
after about an hour and see if it is still correct.
Then you can calculate the amount of Epsom Salt per gallon and times 5 for the 5G bucket and mix and add Kent's in the amount you figured initially.
Mix and treat with water conditioned to make the water safe, and temperature.