Stubborn Ammonia?

I can’t figure out what’s up with this tank! It’s 10 gallons and has been set up for several months. I know it’s cycled because there was a nitrite spike a couple months ago followed by nitrate. Both are now at zero (the frogbit keeps the nitrate at zero even though my tap water has nitrate!).

But the ammonia is proving stubborn. The API test kit stays at 0.25 ppm, no matter what I do!! It can’t be a dead fish, as I only have two platies in there and I’d know if one died.

Do you test for ammonia before or after feeding the fish?
If before then the test kit will be reading the fish food that was in the water.

Test your tap water for ammonia.
Test some distilled water for ammonia. If there is any ammonia in the distilled water then the test kit is dodgy.

Is there any driftwood in the tank? it might be rotting and producing a small amount of ammonia.

Colin_T said:

Do you test for ammonia before or after feeding the fish?
If before then the test kit will be reading the fish food that was in the water.

Test your tap water for ammonia.
Test some distilled water for ammonia. If there is any ammonia in the distilled water then the test kit is dodgy.

Is there any driftwood in the tank? it might be rotting and producing a small amount of ammonia.

Click to expand...

Thank you so much for the quick reply!

I test before feeding the fish. Nope, no driftwood. I tested the tank water again today, and the tap and RO water (which I mix with the tap water for water changes, because of the nitrates in the tap). And...

They all look pretty yellow to me today. Lol. Maybe my eyes were playing tricks on me? This isn’t right after a water change either, I was going to do one last night but I ran out of time. Could’ve sworn it’s been greenish before...

I would say it is yellow
What the hell sort of test kit puts 0 and 0.25 ppm as the same colour?

It looks like the tank water has 0 but the R/O and tap water have 0.25ppm ammonia. It's probably from chloramine in the water and if you are using a dechlorinator that binds to ammonia, it will be safe for a bit while the filter bacteria will pick it up.

If you are getting nitrates then I wouldn't worry too much.

Colin_T said:

I would say it is yellow
What the hell sort of test kit puts 0 and 0.25 ppm as the same colour?

It looks like the tank water has 0 but the R/O and tap water have 0.25ppm ammonia. It's probably from chloramine in the water and if you are using a dechlorinator that binds to ammonia, it will be safe for a bit while the filter bacteria will pick it up.

If you are getting nitrates then I wouldn't worry too much.

Click to expand...

Ok, thanks! That eases my mind a bit! Although the nitrate reading from the tank is zero. It was around 20 before I added the frogbit, though, and like I said I had that nitrite spike, so I’m pretty sure it’s cycled.

As for the test kit, it’s an API test kit—it’s a little easier to tell the 0 and 0.25 apart in person but I do wish the difference was a bit more obvious!

If you're really concerned, fill up a large plastic storage container with water and add frogbit to it. Give it lots of light and leave the plant in the water for a week. It will use up any ammonia in the water and you can then use that water for water changes.