[Rainer]

Is there an easy way of calculating ending pH without relying on trial and error?

I've seen quoted ranges for DI of 5.5-7.0 pH, but understand the value can swing wildly from the lack of buffering. Mixing DI with 7.6 pH (8 dGH, 6 dKH) tap at 1:1 results in a pH of 6.8 and 165 TDS after sitting over a week. I'm aiming for a pH of 7.2, dissolved solids around 225. I'm guessing a 3:1 ratio might work but don't have time for trial and error.

Any suggestions?

 

[Aqguy]

Its trail and error until you find what works for your primators , after that I don't even need to check because its always the same

 

[Hoppy]

It is far better to ignore the pH than to spend the effort required to get the water to the exact pH you want (for whatever reason). The pH is a result of what is dissolved in the water, including atmospheric CO2, so it can vary quite a bit. Our goal should be to avoid rapid changes in KH, which is easy to do, not to maintain a constant specific pH.

 

[Diana]

Set the GH to what your fish or other livestock want.
Get the KH sort of about the same.
Ignore pH.
If you have black water fish filter the water through peat moss for the organic acids. That will also lower the pH.

 

[Rainer]

Thanks for the responses, folks. Adjusting GH and KH shouldn't be difficult. I need pH above 7.0 for the sake of the snails, to prevent shell damage, and am trying to match the conditions that some finicky shrimp I'm thinking of getting are bred in.

 

[Diana]

Do, here is the quickest method:
1) Set up 10 glasses of water, each with a different amount of carbonates. (never mind anything else). Dipstick test the pH after the baking soda or whatever is dissolved.
2) Use the dose you like of carbonate raising material in your tank.

Test time:
I bet I could do that in under half an hour, set up to tear down.

Possible materials to alter KH:
Baking soda (1 teaspoon per 30 gallons raises the KH by 2 degrees)
Potassium bicarbonate (1 teaspoon per 24 gallons raises the KH by 2 degrees)
Coral Sand
Oyster Shell Grit
Limestone sand

The first 2 are added to the water when you do a water change. Make the KH right.
The last items can be used in the filter to maintain the higher KH between water changes if the KH has a tendency to drop.

Do not use montmorillonite clay substrates without a good KH program ready to use. These materials (Safe-T-Sorb, Turface) and some of the ADA products tend to remove the KH from the water. They will stop after a while, or you can blend them with coral sand.