.25 ppm Ammonia, concern?

Posted by: Clay N' Pray

.25 ppm Ammonia, concern? - 08/10/19 07:50 PM

.5 acre, 7.7ph farm pond.
Heavily stocked with CC, LMB & HBG.
I feed daily and have aeration 8hrs a day.
Is .25 ppm Ammonia a concern?
Posted by: Quarter Acre

Re: .25 ppm Ammonia, concern? - 08/11/19 08:14 AM

According to...


0.25 ppm is on the high end of acceptable.

I'm way too new to pond chemistry, but my first thought is to cut back some on feeding and consider removing some fish. If nothing else, keep an eye on it. A good rain with some flow through could help.
Posted by: Clay N' Pray

Re: .25 ppm Ammonia, concern? - 08/11/19 12:19 PM

Thanks for the link QA.
The "perfect storm" has occured in my BOW.
All the following have contributed to the ammonia buildup.

- Little to no rain in over a month.
- PH is at a record high. (7.6 +/-)
- feeding heavier than ever before
- high temps
- high biomass

I (incorrectly) thought that aeration helped with ammonia buildup.
The pond has always struggled with low PH due to excessive watershed, but this drought has allowed it to "percolate".
Definitely a learning moment for me.

My first clue was lethargic acting fish.
Just to pass along my newfound knowledge, ponds with low PH rarely have ammonia buildup issues. This is probably why I have never had this problem before.

On a positive note, I'm seeing what I *suspect* is a slight alge bloom. This will be the first time in 15 years this BOW has had anything close to a bloom. The low PH, combined with turbid water have never allowed it to be what I would call fertile.

I am crossing my fingers for rain.
Crazy that I would add thousands of lbs of ag lime to raise the PH...Then when it gets
To the ideal level, I want to lower it again!
Posted by: snrub

Re: .25 ppm Ammonia, concern? - 08/11/19 12:46 PM

Why do you think aeration does not help with ammonia buildup?
I would think the more the water is exposed to the surface the more ammonia gas would dissipate. I would think running the pump more hours would help.
Posted by: Clay N' Pray

Re: .25 ppm Ammonia, concern? - 08/11/19 12:50 PM

Originally Posted By: snrub
Why do you think aeration does not help with ammonia buildup?
I would think the more the water is exposed to the surface the more ammonia gas would dissipate. I would think running the pump more hours would help.

All the aquaculture studies I've read says aeration has zero effect on ammonia and may actually make it worse.

ETA, found it.
See below.

Increase Aeration
"The toxic form of ammonia (NH3) is a dissolved gas, so some producers believe pond aeration is one way to get rid of ammonia because it accelerates the diffusion of ammonia gas from pond water to the air. However, research has demonstrated that aeration is ineffective at reducing ammonia concentration because the volume of water affected by aerators is quite small in comparison with the total pond volume and because the concentration of ammonia gas in water is typically fairly low (especially in the morning). Intensive aeration may actually increase ammonia concentration because it suspends pond sediments."

Scroll to the bottom to see the section titled "Managing ammonia"

Posted by: Joey Quarry

Re: .25 ppm Ammonia, concern? - 08/11/19 01:41 PM

Any time you have measurable concentrations of ammonia in your water, is a concern. Will it kill your fish? Most likely, No. NH3 is pH and temperature dependent and your test only shows, one time when you tested the water, there was some ammonia.

Dumping "thousands of pounds" of lime in your BOW unlocked previously unavailable phosphorous, leading to a bloom. It suggests your pond bottom is acidic. Just a guess...

While it is true aeration is not much help in controlling ammonia, maintaining DO levels while you have a boom and bust cycle of phyto/algae bloom, is definitely helpful.
Posted by: Clay N' Pray

Re: .25 ppm Ammonia, concern? - 09/22/19 06:05 AM

30 day update:

Tested water again yesterday.
Ammonia is now at .50ppm.
PH is shows 7.6.

It basically has not rained in a month.
The PH has never been this high, nor has the water level been this low.
No rain expected for weeks.

I have stopped all feeding.
Aeration is on night schedule, 8hr.
Water is cooling off.
CC and bluegill are not feeding.

At this point, might it be useful to add some hydrated lime to decrease PH?
That would help with the ammonia right?
A good rain would have the same effect but none is forecasted.

I have no method of adding water.

My pond is .5 acre and currently 2.5 feet below full pool. I read this method at be useful:

Add standard, white household vinegar to your pond if the pH testing kit reveals a pH that's above 7.5. Use 1/4 cup of vinegar for every 500 gallons of water in your pond. The acid in the vinegar helps neutralize the alkalinity and lower the pond water's pH levels.Dec 10, 2018

Posted by: TGW1

Re: .25 ppm Ammonia, concern? - 09/22/19 08:51 AM

From all of my experience and that's a lot with hydrated lime, it will raise your pH, it will not lower it. A 7.6 is not all that high, I have seen an 8pH in my pond before. It did not kill any fish that I am aware of. Droughts suck, we see droughts a lot here in our Texas water levels where they fluctuate quite a bit. So, I can relate with what you are seeing. I also have good numbers of fish and when the water drops it concentrates them into a smaller area, makes then a little easier to catch. So, maybe the thing to do is to remove some biomass in the pond. I would think that would help to eliminate adding more ammonia. I am no expert when talking ammonia an how much a fish can live with.
Posted by: Clay N' Pray

Re: .25 ppm Ammonia, concern? - 09/22/19 10:53 AM

I added 7 gallons of white vinegar today just for curiosity. It cant hurt.

I think my math is close for acre feet:

.47 acre
Average depth 2.8ft
.615 acre feet.

One acre foot is 325,851 gallons.

So seven gallons of vinegar would treat 28,000 gallons of water.
Keeping in mind the KH is so low it shows zero on the test, so no real buffer.
I probably didn't even make a dent.

The .50ppm of ammonia really has me worried. I'm hoping the cooling water temps help some.
Posted by: Joey Quarry

Re: .25 ppm Ammonia, concern? - 09/22/19 04:05 PM

The percent of NH3 of total ammonia is pH and Temperature dependent. I may have missed it but I don't see a temp reading? Chances are, with a pH of 7.8'ish you probably ok, unless your water is over 80 degrees?
Posted by: Clay N' Pray

Re: .25 ppm Ammonia, concern? - 11/16/19 10:53 AM

We finally got rain and the influx of water diluted the ammonia buildup and lowered the PH. (Low PH helps with ammonia buildup).
It was at .50 ppm.

I now know that I have surpassed the carrying capacity of the pond when in drought conditions.

Lesson learned, habitually low PH is not neccesarily a bad thing.
I tried to counter the low PH with large amounts of crushed limestone.
After about 30 days of no fresh water, the PH went into overdrive, and so did the ammonia.

Definitely a lesson to be learned here.