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.

 

[Mmathis]

Hello and welcome!

The thing about pH, is not how high or low it is, but you want it to stay at a consistent level (highs and lows, ups and downs are harmful). The fish will adapt. I add crushed oyster shells to my water, as this helps keep the pH buffered. My pH tends to run high.

I commend you for checking your water!! Keep in mind that the smaller the body of water, the harder it will be to keep your water parameters even. It’s an ecosystem, and it does have limits!

 

[j.w]

@HuskyPsyd

 

[HuskyPsyd]

Thanks for the info! Just added baking soda today.

 

[WaterGardener]

What is the pH and KH now?

 

[HuskyPsyd]

What is the pH and KH now?

Yesterday the Ph was down a bit to 8.3, KH was up to 130ppm. GH was at 250 ppm. Nitrite went up to .32 ppm. Phosphate came down a bit but is still high at 7 ppm. Today the PH came up a tad to 8.4.

 

[WaterGardener]

That looks good to me. For reference, 40 ppm phosphates or less is the acceptable level for drinking water. I doubt that 7 is a problem, but I could be wrong. Wouldn't be the first time.

 

[HuskyPsyd]

That looks good to me. For reference, 40 ppm phosphates or less is the acceptable level for drinking water. I doubt that 7 is a problem, but I could be wrong. Wouldn't be the first time.

Thanks for your help!

 

[WaterGardener]

You are welcome. Please keep asking questions and doing your own research. I always like to verify what I read online, to be sure I have the facts, not just someone's opinion.

Best of luck with your pond and welcome to the site. Lots of knowledgeable people here willing to help.