Do I have to many fish for my pond

[Bart]

Well I admit and it is obvious that I don't know what the heck I am doing. I recieved the info about the corn and barley from a Botanical Garden Director. Other than beneficial bacteria and the barley and corn these are the only items I have put in to clear things up.
The 6.5 PH was a couple of weeks ago. The 9.0 PH was taken today.

 

[capewind]

Again, I do not want you to feel like I was critizing, just trying to get a read on where everything is at so people can give advice that will actually help, and not confuse the situation more.

Can you get TWO new PH readings for us? One as the sun is setting, and another first thing tomorrow morning as the sun is coming up? Specifically, what I want to know is how far apart, if at all, your AM and PM PH results are.

 

[Waterbug]

Well I admit and it is obvious that I don't know what the heck I am doing. I recieved the info about the corn and barley from a Botanical Garden Director.

Yes, it's that bad. Myths about ponds are everywhere, books, "experts". I'm just another dude in a forum so you shouldn't believe me either. Check it out for yourself. There isn't, unfortunately, any single authoritative source on backyard ponds.

The 6.5 PH was a couple of weeks ago. The 9.0 PH was taken today.

Stop testing pH, it does you no good. Instead test KH and GH. More importantly Google "pond pH buffering", but read many sources. Also Google "aquarium pH buffering". Aquarium hobbyists are far, far more knowledgeable on the subject of keeping fish and water quality than pond hobbyists who are ruled for the most part by myths. Ponds are easy to keep, hard to kill fish, so myths aren't weeded out as fast. With aquariums myths kill fish really fast and fish are more expensive so they've been more serious about fact vs myth.

Without buffering pH can be 6.5 and then 9 an hour later. Buffering stabilizes pH. When you test and know KH, and to a lesser degree GH, you can tell what your pH will generally be over the next day, week or month. Testing pH tells you want was going on when you took the water sample, not what pH is a minute later. If your KH is say 100ppm or more I'd say your previous pH tests were in error. If KH is say under 40ppm I'd say that explains pH swinging between 6.5 and 9.0 and probably even wider.

I have no idea why you would want to pH lower than 9.0. The Botanical Garden Director again?

 

[capewind]

WB, assumption on my part, but since it hadnt been mentioned, was thinking it was unlikely he had a KH test. Didnt want to confuse more. Would an AM/PM test not tell us if there was a swing?

 

[Waterbug]

The lower the buffering level the less stable the pH. When not buffered gas exchange alone can change pH. So just the act of taking the sample could greatly change the measured pH.

The standard AM/PM cycle of pH, low in the AM, higher in the PM, still depends on some buffering to appear. How much swing seen in this cycle indicate how effective the buffer is. For example a pond can be buffered with say oyster shell.If acid is added the oyster shell will indeed use up the positive hydrogen ions produced by the acid, but it will do so rather slowly. Where as something like baking soda dissolves in the water and sucks out positive hydrogen ions very fast and the AM/PM swings will be less. So while many things are buffers, some are better than others.

Water can be buffered to pretty much any pH. Adding a lot of acid would want to stay at a low pH because the acid released a bunch of positive hydrogen ions which is what pH is measuring. Or water can be buffered to a higher pH by adding something like baking soda, measured by KH. pH wants to stay high because positive hydrogen ions react with the buffer to form another substance, so there are fewer positive hydrogen ions to measure and pH is higher.

When water isn't buffered, either low or high, it means there aren't a lot of positive hydrogen ions to measure, which would mean high pH, but there also isn't anything sucking up what positive hydrogen ions there are, so water can be low pH, at almost the same time. Swings are at the whim of simple gas exchange. So to me pH is a pretty worthless test on its own.

 

[Bart]

For what its worth, here are the ph readings for last night at just after sunset and then again this morning just before sunrise. They were both 9.0 No difference.

 

[Waterbug]

So perhaps you had some incorrect readings?

Proper sample method imo: Use a HDPE bottle. Must be very clean, no soap remaining, at all. Wash the container 3 times in pond water. Holding the container upside down push it down into the pond about 12", but at least 12" off the bottom, so for less than 24" deep mid way. Then turn the container upright so the air escapes and water goes in. While still underwater put on the cap. Remove sample from pond. Out of the sun and asap perform the test. Don't shake or stir the sample.

Samples for KH doesn't need to be as precise, but good practice.

 

[Bart]

Ok Waterbug, I just run another test like you suggested and it came out with the same reading. 9.0
I have one more question. When I built my water fall which runs down about 8 ft before it dumps in to the pond. This waterfall is lined, where the water runs, with curshed limestone. Will this rock leach out anything that will effect the water test readings?

 

[shakaho]

100 gallons per goldfish is fine. But if your pond has been running for more than a year, I wonder why you have so few fish in that much space. Goldfish are notorious for overpopulating a pond. Have you lost fish to predators or disease?

You are feeding 1/4 cup of food a day. That's more than 3 times what I feed, and my fish are larger than yours (and also quite fat). There's plenty of food in your pond. Try cutting back to a tablespoon a day, and see if that helps with your water condition.

 

[Waterbug]

Ok Waterbug, I just run another test like you suggested and it came out with the same reading. 9.0
I have one more question. When I built my water fall which runs down about 8 ft before it dumps in to the pond. This waterfall is lined, where the water runs, with curshed limestone. Will this rock leach out anything that will effect the water test readings?

How'd the Google pH buffer go?

 

[CometKeith]

Hi Bart. High PH means your pond is very alkaline or lime. Crushed limestone will decompose and add lime to your pond and raise the PH. I had this problem when i first built my pond. I lined the inside with pavers to make it look like an old well. It looked really good but had very high PH until I took out the pavers. Also to make matters worse I had limestone (flagstone) in my waterfall. When I changed all this almost overnight my PH dropped to more manageable levels. I have found that goldfish are more tolerant of ph's over 9 than Koi. i'm sure some of the "experts" here will disagree with all this. Now I use slate or granite rocks in my waterfall and those pavers are long gone and just gathering dust on the side of my garage!

 

[Waterbug]

How were your Koi less tolerant? I've read debates about the colors in Koi being effected by pH, no consensus that I could tell, but not really something I follow very close.

In order for pH to drop almost overnight from 9 to some manageable level, let's say 8, would require a lot of acid or very low KH which the limestone would have made high in theory. If there was a sudden huge increase in acid it must have also just as suddenly stopped for some unknown reason. It doesn't really make any kind of sense from the standpoint of science.

Apparently only in ponds does limestone raise pH to 9 and higher if you read a lot of pond forums. If you read a lot of aquarium forums they also say limestone raises pH to "very high" and "dangerously high" levels. But to them these high levels are 7.0-7.8 generally. And they're putting a lot of crushed coral and/or crushed limestone. For example to do the same in a pond would require about 6" of crushed rock covering the entire pond. And it also raises KH to "high" range of about 40 ppm, which in ponds we call "very low" KH.

And in the world of science calcium carbonate, the part of limestone that effects pH, we know calcium carbonate precipitates back out of solution as pH gets above 7.0. To get 9.0 pH with calcium carbonate takes lab conditions.

We live in a strange world.

 

[HTH]

I have no answer but wanted to say that not all limestone is created equal. Some will have a greater impact on the water then others.

 

[HARO]

Sorry I'm a bit late, but I've been busy and just found this thread. GROUND CORN???? Are you trying to feed it to your fish? What was the purpose of this, as stated by the "expert"? Inquiring minds want to know. :dunno:
John

 

[capewind]

Sorry I'm a bit late, but I've been busy and just found this thread. GROUND CORN???? Are you trying to feed it to your fish? What was the purpose of this, as stated by the "expert"? Inquiring minds want to know. :dunno:
John

I had to do a websearch ... wont comment, so you can form your own opinion ... I'll just say not for me ... do a search.