Ph will not lower in pond

[Debra]

water coming into koi pond perfect ph… pond is 625 gallons .. use milk crates and 15 year old concrete block to hold crate in place have couple bricks.. removed the slate the ph is 8.0 to 8.5 to high .. did water change by half added ph reducer .. cannot get it lower ? Have 4 small plants .. what is causing this ??? The concrete blocks were used for years in old pond no issues .. help!

 

[Mmathis]

A Ph of 8-8.5 is not too high.

 

[Stephen Noble]

Welcome Debra!
Well seasoned concrete blocks should not be a problem unless they have been scraped and you use a bunch of them in your 624 gallon pond. Truthfully, your pH is not something I would worry about. 8.5 is high but still within the safe zone. What I would worry about is trying to artificially manipulate your pH. What is the pH without you doing anything to the water?

Here is some Noble information:

Regenerative Agriculture Archives

www.noble.org

 

[j.w]

and welcome @Debra

 

[Michael from Daytona]

I, too, have encountered high pH (8.6) in my two ponds, each one 600 gals, connected by a sluice/waterfall so that chemical conditions in one are pretty much identical to the other. All other testable indicators (phosphates, nitrates, hardness) have been well within normal limits. I also have had some amount of leachable base (concrete blocks) to hold water plants at their proper depth which I added without thought to sealing them. In addition, I had to repair a broken concrete waterfall and used bagged cement cast in forms to do that job, although I did remember to put a couple coats of water-based concrete sealer (Seal-Crete) on the repair job.

Anyway, the high pH is stable for now. I even tried to bring it down with 2-cup doses of distilled vinegar applied gradually. The pH did come down slightly for several hours but by the next day, was right back where it was before. I stopped messing with it out of concern for my fish which, using their behavior as an indicator, were doing just fine in the alkaline water.

I think the message here is, don't fix what isn't broken.

 

[Debra]

I, too, have encountered high pH (8.6) in my two ponds, each one 600 gals, connected by a sluice/waterfall so that chemical conditions in one are pretty much identical to the other. All other testable indicators (phosphates, nitrates, hardness) have been well within normal limits. I also have had some amount of leachable base (concrete blocks) to hold water plants at their proper depth which I added without thought to sealing them. In addition, I had to repair a broken concrete waterfall and used bagged cement cast in forms to do that job, although I did remember to put a couple coats of water-based concrete sealer (Seal-Crete) on the repair job.

Anyway, the high pH is stable for now. I even tried to bring it down with 2-cup doses of distilled vinegar applied gradually. The pH did come down slightly for several hours but by the next day, was right back where it was before. I stopped messing with it out of concern for my fish which, using their behavior as an indicator, were doing just fine in the alkaline water.

I think the message here is, don't fix what isn't broken.

I read that clay added to pond for clarity etc can change ph and also algae can … never had this issue… thank you for your reply

 

[Lisak1]

1. I'll repeat it as it seems to be getting lost in the shuffle - those pH numbers are not too high. And rapidly changing pH is far worse for fish than high pH. Chasing pH is never a win for a pond.
2. A 600 gallon pond is not a koi pond, so hopefully you aren't keeping koi. That's a good size for goldfish.
3. Whenever someone can tell you exactly how many plants they have, they have too few plants.

Welcome to the GPF - lots of friendly, helpful, experienced folks here who are happy to help!

 

[WaterGardener]

The pH in my pond stays at 8.3 and has for years. I try to keep mine at that level since that is where it is stable. As Lisak1 said, yours is not too high.

There is no such thing as a perfect pH for goldfish or koi. They will do well in pH up to 10, as long as it is stable. But if you are aiming for a certain lower number, the pH will be constantly jumping around while you to try to adjust it, stressing your fish. It's better for them to leave it where it is.

 

[Mayank]

Our pH has always been 8.0 rising to 8.2 going up to even 8.6 in the late afternoon. Last year, the pond place said, "oh, that's high and here is this powder you can add to lower it." Tried it for a day or two and it just didn't work and did some research and realized that I should just leave the pH alone!!! Love that everyone here has the same opinion!

 

[addy1]

Welcome to our forum!