Sudden spike of ammonia in an established tank

[tred709]

Hi Folks,
I have a 30 gallon tank that has been set up for 8 months. We are new to the aquarium hobby and got the tank for our son to show him responsibility and as a fun thing for our family to learn and care for together. he has been very active in the care of the fish. He is 6 and loves the fish tank dearly. Our family is learning a lot and we enjoy the fish a lot.
We did significant research before we got the tank and once we did we were very careful to make sure it was cycled before adding fish. We cycled it for a almost month, and weekly took samples of the water to the pet store to be tested and waited until we got the go ahead from them.
We have had no issues, and we check the levels weekly, and do a 15 % water change weekly. During this process we vacuum a third of the tank each time. The water has been crystal clear and we have had healthy fish from the get go. Most of our fish have been there since the beginning.
I did a usual clean yesterday and checked the levels tonight when I noticed our neon tetras were all huddled together and the fish seemed to be acting a little different then usual. All levels were good except the Ammonia and PH. The water is also just a tad bit cloudy, hardly noticable. As mentioned above it is usually so clear it looks as though there isn't even water in it. I have corrected the ph with a booster as the water where we live is known amongst aquarists to not hold ph levels well.

We have,

4 Molly's
6 neon tetras
4 young Molly fry from 3 different batches since we got them 8 months ago
2 black phantom tetras
1 common Pleco

We also have two Aqueon quiet filers, 30 and 50

I will do another water change tomorrow, and over the next few days to see if that helps, but my question to you is what could cause this sudden change in ammonia?

Sorry for the long post but wanted to give you the full picture.

 

[Mifsud]

Is everyone you listed currently present?

 

[tred709]

Of the fish? Yes.

 

[Mifsud]

Well, ammonia is produced by decaying organic material and removed by proper filtration. So a large spike could in an established tank could be cause by a death in the family, filtration problems, or even a mischievous 6yo.

What type of filter media do you use?

 

[tred709]

We have 2 Aqueon quiet filters. A 30 and a 50. I vaccume just about half the tank every week. There have been no deaths in the tank recently. As far as I know both the 6 year old and his dad have not been feeding the fish beyond the morning feed we do every day. We also never let him feed the fish alone to assure no over feeding.
Should I do a large water change today, say 75%. Or perhaps I should change the filters. One has been there for a month and the other was changed about two weeks ago. I never change them both at the same time. It just seems strange to me as like I mentioned above we have not had any issues whatsoever to date. I'm nervous of stressing the fish.

Thanks for your help.

 

[BBradbury]

Your Tank

Hello tred...

A couple of things I noticed in your post, is that you only change 15 percent of the tank water a week. That's not nearly enough to maintain safe, stable water conditions. You're leaving most of the dissolved waste in the water. A 30 gallon tank is fairly small and needs half the water changed every week. Another thing, is the use of chemicals in the tank water. I don't use them. You never know how the fish, plants and good bacteria that use the dissolved wastes for food will react. Sometimes, it's a negative reaction.

I'd start a more aggressive water change routine. Start removing and replacing more water and don't worry about the water chemistry. Fish and plants do a very good job of adapting to most public water supplies. Just treat the new water with a product like Seachem's "Safe" to remove the chemicals the public water people put into the tap water to make it safe to drink.

Most, if not all problems with a tank are water related. Keep the tank water pure and the fish and plants will take care of themselves.

B

 

[tred709]

Thanks for the support. I up to about a 4 months ago never used any chemicals. I was having trouble getting the PH levels to a good lace when I went to an aquarium store (this place only deals in fish and fish care and are hard core knowledgeable peeps for both salt water and freshwater care , and they told me that where we live it is quite common that PH is an issue due to the water here. They recommended a product to help this so I use it from time to time whenever I need to, but not every week. So I'm not one for piles of chemicals.
I'm not precise on the 15%, but usually its anywhere from 15-25% on a weekly basis. The tank has been pristine clear and as I mentioned most of these fish we have had since the beginning, and there have been 3 batches of Molly frye so I would think that the environment is normally healthy.
I just checked the Ammonia and PH levels again and they now seem to be perfect. So I guess a 20% water change did the trick last night, and the filters did the rest. The water is crystal clear again.

Thanks for the feedback everyone! I love this site. I've learned a lot here.

 

[enrgizerbunny]

As far as the ammonia is concerned, maybe a mini cycle caused by new filter media, but that doesn't make sense with two filters. I would do 50% water changes to help alleviate the ammonia as well as the cloudiness.

I use crushed coral in my filter (in a bag made of cut up women's tights) to help maintain a stable pH. It's much more effective than a pH booster because it lasts longer. Mine has been there for 6 months and I still haven't had to add any.

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