Water change caused ammonia spike! Help!

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katw1986

Aquarium Advice Regular
Joined
Dec 30, 2024
Messages
56
Location
Barrie ontario
Did a 25% water change in my 5 gallon tank yesterday with just my one betta fish. It has been cycled for awhile now. He was not himself this morning so I checked the water and ammonia is at .50!!! Did an immediate 50 % water change. What caused this?! Should I change more water tonight If it still reads high?

Poor betta is at the bottom sluggish and not looking good 😟😟😟😟😟
 
The only other thing I did was scrub algae off a couple of his rocks, I wonder if that was enough to cause ammonia?
 
Have you tested your tap water for ammonia?

What where the full set of water parameters when you did the test prior to the water change?

What are your water parameters now, after the water change?

Are you frequently doing water tests? If so, what is a typical set of water parameters?

What is a typical water change schedule? How much, how often?

Have you done any aquarium/ filter maintenance recently? Changed a filter cartridge, vacuumed the substrate?

Scrubbing rocks won't have released ammonia per se, but the microbes that are responsible for the nitrogen cycle live on surfaces, including on rocks. It's possible that the cleaning removed some of these microbes setting your cycle back to some degree.
 
Hello. A 25 percent water change still leaves 75 percent of the pollutants in the water. Small tanks need at least half the water removed and replaced every few days. A 50 percent water change performed every three to four days isn't too much. If you're not in the habit of doing this, you need to slowly work up to it. Small tanks are a challenge for even the most experienced tank keeper. Remember, the more water you remove and replace and the more often you do this, the healthier the fish.

B
 
Hi, here's the update.

Did a 25% water change yesterday evening just to clean the tank because it's been a couple weeks. Noticed some algae on the decorations so cleaned them (just cleaned with a brand new scrubber and used tank water). Added water conditioner when we did the water change.

This morning, I noticed he was really not himself, so I tested the water. Ammonia was at .50. Did an immediate 50 % water change and added more conditioner.

NOW, he is hiding in a rock, comes out periodically and then goes back in the rock to hide. I just tested the water again. I have the masters kit. Here's the parameters:

To me, it looks like ammonia is at zero. I'll attach pics. But it looks yellow.

Nitrite: 0

Nitrate: 5 ppm (this is where the tank was at before, after it cycled.

PH: Seems to be around 7.4

Where do I go from here?!
 
I would continue to monitor the water parameters and change water as needed. If your ammonia and nitrite continue to stay zero then the ammonia spike was just something temporary or maybe a false positive test reading.

As to your bettas behaviour, without anything else to go on, continue to monitor the fish. It could just have got spooked by the ammonia spike and needs a bit of time to settle back into a more usual behaviour.

There has been a lot going on with its environment. 2 water changes close together, the rocks have been removed and replaced, lots of water tests, maybe he just needs things to return to a more normal routine.

Is the fish still eating?

How old is the betta?

Adding a background to an aquarium rather than it being open on all sides helps fish feel more secure in their environment and less prone to hiding, so consider that.
 
Not sure how old he is but we got him about a month ago.

He ate this morning . Should I skip his feeding tonight since he's so stressed?

Thank you!!
 
I would see if he will eat. Remove the food if he doesn't.

Old age shouldn't be a factor then.

You could also try leaving the aquarium light off for a bit. See if a little less brightness makes him a little braver. And if you can observe from a distance, maybe your presence is spooking him.
 
It's a waiting game at this point 😟 came into the room to put my son to bed and he's still in the rock, I've been keeping all the lights off
He is wedged against the wall of the rock and his fins were not moving. But he's still upright. I wrapped a towel around the tank to keep it dark

Will see what happens in the morning 😟
 
If the betta comes out, or you are otherwise able to get a good photo, post something. Better still upload a video to YouTube and post a link.

There might be something else going on, but without any symptoms other than hiding there isn't anything to go on. Maybe someone can spot something.
 
Checked on him this morning and he's just at the top of the tank motionless, but he does flinch a little bit when I check on him, so I'm assuming he's sleeping

Just letting him be and keeping the tank dark, and crossing my fingers
 

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Ammonia was zero last night when I checked
Check your nitrate level. If you are using the API liquid test, make sure you shake the reagent bottles really well before testing. The fish's fins are clamped which is a sign of water quality issues. In reading your whole thread, the nitrates should not be consistent after the tank cycles. They should always be rising since any ammonia being produced in the tank is being converted to nitrates in the process. If your tap water has nitrates in it, you will need to use another source for water to do water changes to keep the level low. (y)
 
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