Fish Pond pH Control | What Happens If I Reduce My Garden Pond ph Too Quickly?
Many of my readers are curious to know about the problems and issues other fish pond owners have or are simply wanting to build up a knowledge base just in case a similar situation arises in their own ponds ...
From time to time I will be sending out some of these Q & A (Questions & Answers) as part of my on going news letter series. Hopefully you will find them of some use.
Recently I received a question from Emma who was concerned about the pH levels in her pond, in particular she wanted to know what would happen if she reduced her garden pond pH too quickly? ...
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This is what Emma wrote ....
"Please can you help? I have a fish pond made from brick and concrete. I've added 3 gallons of Muriatic acid which is causing my garden pond ph level to come down but I'm worried about the effects this might have on my pond fish. I have fifteen 6 to 12" long koi and a few common gold fish.
Please advise me if I am doing the right thing or if I should let the pH drop naturally over a period of time?
Many Thanks
Emma Hanklin"
Here is my response to Emma
"Hi Emma
Yes, brick and concrete can make the pH of your pond higher than those of a preformed pond or liner pond.
Just in case you are not aware pH is classed as acidic (below pH 7), neutral (pH 7) or alkaline (above pH7). For the majority of garden ponds the accepted norm and the ideal ph level for a garden pond for both aquatic life and plants is a garden pond pH between 6.8 to 8
The net effect of lowering the pH of pond water too quickly is to cause possible stress and in the worst cases possible aquatic life fatalities.
The secret is to lower the pH carefully and slowly over a period of several days. Please be aware that pH measurements are actually a logarithmic scale and a drop from a pH of 8 to 7.9 is actually a difference of 10x
On the other hand however goldfish, Koi and many other aquatic life forms are capable of surviving very well under various pH ranges, once they have become used to them. Pond pH problems are usually because of a rapid pond pH adjustment.
It is quite common for many ponds to have a pH above neutral. A garden pond pH of 8 is ok.
One of the biggest garden pond problems encountered is a high pond pH. This has a detrimental effect because a high pond pH makes ammonia more toxic to the pond inhabitants.
Ammonia is released into ponds by aquatic life and from decaying organic matter such as leaves and plants. It is highly toxic and needs to be removed by your Biological Pond Filter.
Unfortunately you never specified the size of your pond in terms of it's depth, dimensions and volume but please bear in mind that having a high pH in a small, over stocked pond containing an under sized biofilter can lead to potential ammonia based problems.
In your case I am presuming that you have a fairly large sized pond due to it being constructed from brick and concrete?. In my experience the majority of smaller ponds are either preformed or liner ponds.
Hope this helps!
ps be careful handling Muriatic (Hydrochloric) acid its nasty stuff. Whatever you don't inhale the fumes"
For those of you who are interested in knowing the correct fish stocking density or volume of your pond, please take a look at my FREE pond calculators by clicking the link .... save a copy for yourself.
Further information regarding how to control pond ph and how to control massive swings can be seen by taking a look at this article What You Need To Know About Garden Pond pH And Buffering!