PH confusion --- staying high

[KoiKisses]

Hi guys, it has been a while since I've been on the forum.....

My pond had a stable PH of 7.6 for the past two years. When I built the pond, I had done my research, and built the pond breach height equal to the level of my home's floor. On March 12 of this year, we received 19" of rain in 4 hours. As our neighborhood, some 40 years old, has never had flood problems in its history, this was the first. With the water being 6" deep in my house, needless to say, my pond was underwater 6".

The pond was immediately cleaned, but there remains that powder like silt that is slowing making its way out. My PH keeps reading at 8.2-8.4 and I can not figure out why. I have done water changes several times a week since the flood and my tap water is relatively stable at 7.4. We have also had quite a bit of rain as well. Is it the silt that is causing the PH to stay so high?

KoiKisses

[MCA]

Without seeing the powder I can only guess that it is some combination of concrete, mortar, and drywall dust from various parts of the house from the flood. All of those have calcium carbonate components. Hence the high KH and resulting pH. High pH is not really a problem...provided it is stable. The last thing you want is to start putting in acids to force the pH down to 7.x.

Watch over time to see if the amount of powder, KH, and pH is getting lower. If not, you may need to put the fish into a holding tank (such as a show tank, pump all the water out, rinse out the pond using sump pumps and shop vacs. Needless to say that takes some planning to get the temp tank ready, pump and vac ready, push nets and bowls to capture and move the fish between pond and tank.

[KoiKisses]

Thank you MCA!

I'll keep vacuuming and flushing and watching how the PH responds. No need to set up a temporary tank. All my koi (nine - 16" koi) took the liberty of swimming away. (Needless to say, once I was able to get back to the house later that day, I was running around the yard and neighborhood looking in bushes, ditches, everywhere, trying to at least find one!) No such luck, but, on the bright side, I get NEW babies!

Thanks again,

KoiKisses

[MCA]

Here in Atlanta we had major flooding a couple of years ago when Hurricane related storms came through. A creek rose behind our club president's house. The creek flooded out their pond. After the water subsided, he found around half their koi in little pools and puddles in the backyards of the neighbors.