Need some help with PH and KH

[HuskyPsyd]

Hello, I have a 250-gallon pond with a few goldfish and a good amount of plants. My current PH is 8.6 and KH is 30 ppm. MY GH is high at around 215 ppm. No matter how often I add PH down, by the next day the PH is back up again. I guess this makes sense, as the KH is low. How do I increase KH and lower PH? I was told to buy Seachem's alkaline buffer, but it says on the bottle that it increases PH. Our tap water is quite hard with a PH of 8.6, so water changes do not help.
Thanks!

 

[WaterGardener]

You don't need to lower the pH. The fish will be fine in anything with a pH of 10 or lower. As you have found, trying to lower it will not work and will just have the pH jumping up and down. That is very stressful for the fish, leading to their being susceptible to disease and even death.

You can add baking soda to raise the KH. It should not raise the pH unless you have some unusual water. But since you have hard water with sufficient GH, the pH should not go any higher than it is. The dosage is one cup for every 1,000 gallons or water. I feel the minimum KH should be 100 ppm, but more is not a problem. I keep the KH in my pond around 200.

I would add a small amount of baking soda, like one tablespoon, dissolved in a bucket of pond water, then check the pH and KH. Since the pH of baking soda is around 8.3 or 8.4, it may actually lower the pH to that level. That is where a lot of us keep the pH in our ponds.

It's always a good idea to make changes to the water gradually, over a few days, not a few minutes or hours.

 

[JRS]

Welcome to the forum. I too have a very high pH, and very hard water which makes for stable water chemistry. No problems with the fish.