Ammonia level came up..... Just curious.... Why

[Jimmy Gibson]

I have been checking my pond in the beginning daily, but since it has cycled.....weekly. For months now my ammonia with an API test kit has been yellow with a slight tint of green not anyway near. 25 ppm, nitrates at 5.0 or below and nitrite at almost zero. Some of you that follow my post last weekend I had to do a wholesale water change to rehome 37 4" to 5" Koi. Basically I changed out 3000 gallons of water in a 3000 gallon pond. I use a new charcoal filter to refill the pond ( same kind I have always used with no ill effect). I checked the water this morning and my ammonia is above. 25 ppm, not at 5.0 yet and nitrates is still 5.0 and nitrites almost zero. The Koi are showing no ill effect, no flashing, look great.
My question is did the big water change affect my Nitrosomonas bacteria. I realize inches of fish is not an accurate measure of bio load, but by that standard I have 40% less bioload than I had a week ago. I am sure by next weekend it will be back to normal but Just Curious

 

[Meyer Jordan]

I am assuming that you had to reduce the water level in order to ease capture of the fish. How much was the water level reduced and for what perriod of time did it remain at this reduced level?

 

[Jimmy Gibson]

I am assuming that you had to reduce the water level in order to ease capture of the fish. How much was the water level reduced and for what perriod of time did it remain at this reduced level?

I would say maybe 400 gallon left..... And I started refilling immediately. The pond was full again about 5 hours later. So it was almost a complete water change out

 

[bettasngoldfish]

The cycle should not be hurt by a 100% water change. Unless you scrubbed the sides of the pond or got crazy cleaning the filter.

When I do large (sometimes 100% water changes) in my aquariums or pond I do not clean the filter at the same time.

The water doesn't have the bio bugs you need to keep a mature pond, it's the filter. Other things like rocks, the bottom and sides of the pond have the good stuff on them too. That's why it's not recommend to scrub anything clean.

 

[Meyer Jordan]

The cycle should not be hurt by a 100% water change. Unless you scrubbed the sides of the pond or got crazy cleaning the filter.

When I do large (sometimes 100% water changes) in my aquariums or pond I do not clean the filter at the same time.

The water doesn't have the bio bugs you need to keep a mature pond, it's the filter. Other things like rocks, the bottom and sides of the pond have the good stuff on them too. That's why it's not recommend to scrub anything clean.

@bettasngoldfish is correct when the vessel that the water change is being performed on is small, There is an enormous difference between a 100 gallon aquarium and a 3000 gallon pond when it comes to time required. In your case 5 hours that no water was being pumped through the filter. In fact, the filter probably did not have any water left in it. In this case the nitrifying bacteria began to die off from lack of Oxygen. The same would be true of the nitrifying bacteria in the biofilm on the pond liner. You may not have lost all of the bacteria, but the population was reduced enough that your pond may go through a mini-cycle until the bacteria has time to re-populate.
And to correct a common misconception, mature water does indeed contain all of the different nitrifying bacteria (they are not able to perform any nitrification until they are attached to a surface), the phytoplankton population and the zooplankton population.
In essence, you are almost starting over. I would recommend closely monitoring both the Ammonia and the Nirite levels.

 

[bettasngoldfish]

@Meyer Jordan You bring a very good point about the amount of time the filter was off.

I know the filter being shut down or dry for any period of time can cause a blip in the cycle. But I didn't consider the time it would take to change that amount of water because I never had a pond that big

Good catch

 

[Lisak1]

In this case the nitrifying bacteria began to die off from lack of Oxygen

I was going to say the same about any bacteria present on the liner - wouldn't it start to die off as soon as it was no longer under water? I would assume it would begin to die off almost immediately if the liner/rocks dried off, which it definitely would in five hours.

 

[Jimmy Gibson]

Well I actually kept the pump running the whole time. I turned off the valve to my skimmer and used the bottom drain. That being said the sides and alot of the bottom liner did dry out. Also the bio material in my skimmer was out of the water for that period of time. Another variable is last week my ph was right at 7.0, this week it was at 7.6 to 7.8 due to the fresh city water going in.

 

[Meyer Jordan]

I would not be concerned about the pH at the moment/ 7.6-7.8 is actually a good reading.
When determining the total Nitrogen conversion capacity of a pond, all submerged surfaces need to be taken into account. A biofilter unit is actually supplemental to the conversion capacity of the actual pond itself, and this is needed only because of the addition of more fish than the pond can handle on its own.
You have lost a fairly good percentage of your nitrifying bacteria, but,as was stated before, they will re-populate. Sometimes in instances such as these, it may take the pond longer to cycle than when first installed. This is due to the very different growth rates of the various bacteria with the autotrophic (nitrifying) bacteria having very low growth rates in comparison to all of the other various heterotrophic bacteria. Add to this that even in a mature biofilm, whether on the liner etc. or in the biofilter, the nitrifying bacteria are typically able to utilize only about 5% of the available surface area. Competition for space at the microscopic level is brutal.

 

[Jimmy Gibson]

Hopefully next spring my Koi will learn how to eat eggs and Koi fry, the only problem this year I only had one spawning size female ( she spawned three times) next year I will have three. Wanted to put a predator in the pond but Sarah won't let me. Thanks for everyone's advice

 

[bagsmom]

On the topic of water changes, I've often wondered if adding city water to the pond -- even with dechlorinator added -- can kill off some of the good bacteria in the filter? My water changes are minimal and I add my dry dechlorinator granules, then spray in the new water. I've had no problems that I know of -- but it does cross my mind if there is an effect or not?

 

[EricV]

Another thing to check is for chloramines. My city uses them and when I dechlorinate water, I get about 0.5 ppm of ammonia as a result. Pretty much undetectable/irrelevant for small water changes, but if you did 100%...

 

[Jimmy Gibson]

Another thing to check is for chloramines. My city uses them and when I dechlorinate water, I get about 0.5 ppm of ammonia as a result. Pretty much undetectable/irrelevant for small water changes, but if you did 100%...

I checked with my local utility last November, the only thing they add chlorine, lime and calgon. Also when I was trying to get my pond to cycle this last spring, I did large water changes pretty often due to high ammonia,.

 

[Meyer Jordan]

On the topic of water changes, I've often wondered if adding city water to the pond -- even with dechlorinator added -- can kill off some of the good bacteria in the filter? My water changes are minimal and I add my dry dechlorinator granules, then spray in the new water. I've had no problems that I know of -- but it does cross my mind if there is an effect or not?[/QUOTE

I checked with my local utility last November, the only thing they add chlorine, lime and calgon. Also when I was trying to get my pond to cycle this last spring, I did large water changes pretty often due to high ammonia,.

Whether it is topping off a pond or performing small water changes, the Chlorine level in the source water will be quickly diluted to a harmless level resulting in no damage to the bio-filter or any aquatic life. The same is true of any Ammonia created by the disassociation of Chloramine.
This is not to say to cease using Dechlor when these actions are performed. Dechlor is safe and it is just a good habit to get into just in case.......well, you know, someone leaves the hose turned on.

 

[Jimmy Gibson]

Just an update to anyone that is interested..... After my huge water change and my ammonia going up, I did a water test today and I am back to my good old yellow with a slight tint of green on my ammonia and my nitrates is almost zero and nitrites, I attribute the nitrates and nitrites being zero is the plants in my pond are going crazy, most of the plants I have growing directly in the water are plants that I took out of our terrestrial garden, other than the cattails, water cabbage, and the water lillies. They are eating the nitrates as quick as they are produced, fish are healthy and happy, so I am happy