Ph high at 9

[Pef1963]

What is the safest way to lower the ph in my pond without harming my fish?

 

[Mmathis]

Well, first of all……. What is the normal pH for your pond, and are you experiencing wide pH swings? Before we start trying to change things, we need to figure out what’s going on. If your fish are used to a high pH, you may not need to change anything, but in a word, “as gradually as possible” is the answer to your question.

What size is your pond, how many fish do you have, what are the results of your other water parameters?

 

[WaterGardener]

There is really no reason to lower it. Fish will be fine in a pH at that level, as long as it is stable. If it is different values at daylight and dusk, then you might have a problem. Otherwise there is no issue with it where it is.

Is your pond new? Mortar from the rocks around the pond can raise pH and it did so in my pond at first. But over time, that level will fall to the pH of your source water.

 

[Pef1963]

Well, first of all……. What is the normal pH for your pond, and are you experiencing wide pH swings? Before we start trying to change things, we need to figure out what’s going on. If your fish are used to a high pH, you may not need to change anything, but in a word, “as gradually as possible” is the answer to your question.

What size is your pond, how many fish do you have, what are the results of your other water parameters?

Thanks for responding. The ph in the pond was previously 7-8 but now it went to 9. I have 2 koi, 5 goldfish and 2 plecostomus. My pond is 1000 gal. Everything else is fine just the high Ph.

 

[WaterGardener]

Are you going to leave those plecostomus in with the goldfish? As several of us said in your other thread, that's not a good idea.