Trying to adjust PH up, with little success

[flboisseau]

I have a pond that is just around 600 gallons. The water chemistry in the pond is pretty good once I got the ammonia down (most likely from dead plant/algae material), except for the PH. That is acidic and nothing I seem to do is having any effect. I have added several dosages of a PH up and crushed oyster shells to the pond. But even adding enough of the PH up so that the water should be alkaline, it does not seem to have moved the meter. Here is some additional information.

• The pond is over 10 years old and seems very healthy
• One goldfish is currently living there and seems to be healthy
• There are tons of frogs and salamanders in the pond
• It has a waterfall and a 600-gallon filter with a fountain
• There is plenty of plant life in the pond also
• It does get a a lot of leaves in the fall, have tried to keep them out without success and have not kept up as we should on removing them in the spring. So some gunk in the bottom, especially the deep part.
• We are in central VA, just south of Richmond.

Any suggestion as to what I can do to address this issue long-term? The goal was to add some more goldfish, but that is not going to happen this year. But we would like to do it next spring.

 

[JRS]

Welcome to the forum.

Actual test result numbers would be helpful. Have you tested KH in addition to the pH?

Types of tests used? Dry strips more prone to errors than liquid kits. Meters calibrated?

Test results of the primary source water of the pond for comparison?

 

[WaterGardener]

PH is easily raised with baking soda. No need to buy something from a pet store. Just check your kitchen cabinet. Large quantities can be found in big box stores for very reasonable prices.

Raising pH should be done gradually so as not to stress the fish. Lots of info on this site if you use the search feature.

The alkalinity in pond water will deteriorate over time, since the nitrogen cycle creates acid. So occasional dosing with baking soda is necessary. It's not something that has to be done daily or even weekly in most cases, so it isn't a burden, just normal maintenance, in my opinion.

Actual numbers would be helpful as already stated. And I agree that KH values would be appreciated. I feel that KH is one of the most important water parameters for a healthy pond.

 

[j.w]

@flboisseau

 

[Mmathis]

Hello and welcome!

How often do you “clean and refill“ the pond? Agree about actual test results for all parameters would be helpful, especially KH!

 

[GBBUDD]

as mentioned simple baking soda will fix what your issue is, and it can do it very quickly but if you have any life ion the pond you wan6t to raise it slowly. adding baking soda will quickly get you to a ph of 8.3 and no matter how much more you add to the pond only the kh will continue to rise the ph will not go any higher.
you ultimately want to shoot for 150 to 200

 

[Lisak1]

I’m curious why in a 10-year-old pond? You’re suddenly concerned about PH? Is this a new development or has it always been this way? The bigger issue with pH is stability not necessarily the actual reading.

 

[flboisseau]

Thank you for your replies.
Regarding the test I am using. It is a new set of test strips, I am cheap and we do not test the water often. I have taken samples to a local family own garden center that is using liquid test, and they seem to match closely to what I am seeing.
Everything in there has adapted to those condition, including the goldfish, and is very happy. My wife does a water change about once every month.
Regarding the results. Here is what I think they are:

alkalinity	0-40
ph	6.8
carbonite	0-40
hardness	50
free chlorine	0
nitrite	0
ammonia	0-0.5

But I have also attached pictures of the test results for the pond and house water. (1 the test chart, 2 pond water, 3 house water)

The house water is acidic and has been softened.
I have a question about the baking soda. How many ounces per 100 gallons should I add?
Thank you again

 

[flboisseau]

Why am I concerned now after 10 years. We want to add some more goldfish? There is only one lonely one right now, though he does have plenty of frogs and salamanders also.

 

[WaterGardener]

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This should help and there is information there about how much to raise the KH in a day. Be sure to raise the KH slowly, over several days, not minutes. It will also raise the pH.

 

[Lisak1]

I can’t tell from the pictures what exactly is your pH currently?

 

[WaterGardener]

Post #8 says it is 6.8.

Since your tap water is acidic, you will need to add more baking soda each time to keep the the alkalinity and pH up.

I highly recommend getting a liquid type KH test.

 

[Laaf]

I would suggest doing partial water changes only, and stop testing the water. And get your goldfish a friend If the fish is happy I would not keep making adjustments based on the test readings.

 

[WaterGardener]

Partial water changes won't help if the source of the water is acidic. You will just be continuing the problem not solving it.

Acidic water is not healthy for the fish or for the beneficial bacteria, and low KH is also a danger. PH will not be stable in low KH water and the pH will crash, killing the fish and the bacteria.

We don't test the water for any other reason than to keep our ponds healthy and create a good environment for the fish and plants. Adding a little baking soda now and then will do nothing but help maintain that. It's not harmful in any way and it isn't adding any harsh chemicals whatsoever that will cause any problems. It will solve and prevent problems.

 

[WaterGardener]

If you are fortunate enough to have tap water that has good parameters, then water changes can help somewhat. That is not the case with the OP.

Please realize that even with water that has a higher pH, doing a 20% water change will change those parameters by only that same 20%. That may not be enough to increase the pH to a safe level.