Ammonia Stuck - Help!


While I have read what seems like thousands of other people's threads searching for answers, this will be my first go at posting my own.

I set up our 36 gallon bowfront 8 weeks ago. Due to the massive snail infestation in our existing tank, I did not take any medium from this tank to help start the new one.

After getting the cycle going seemingly without a hitch (used Stability, and all tests were showing positive signs of moving through an accelerated nitrogen cycle), I slowly started adding fish from our other tank. However, the ammonia level went up to around 1 ppm (API liquid tests) after a few weeks, and has since been stuck there more or less for the last month. I have tried doing 25-30% water changes every other day, I have tried 50% water changes every couple days, I have tried leaving the tank alone, I have tried just small water changes (2-3 gallons) accompanied by gravel vaccuuming on the surface to remove any extra debris daily. NOTHING IS HELPING. Even a 50% water change that cuts the ammonia level in half only lasts until the next day, when it is right back up around 1 ppm.

About a week and a half ago, I got an ammonia alert from Seachem to monitor the free ammonia in the tank, since that is really what matters. This has consistently been registering at "alert", or 0.05 ppm. The fish do not seem to be in distress, nor are they dying, but this ammonia issue is making me crazy! I have not switched out any filter media since starting the cycle except putting in a new ammonia remover a couple of weeks ago. I also have not rinsed the biosponge in about a month, so it is likely due for a rinse in the tank water after my next water change.

Does anyone have any suggestions? My tank and parameters are below, as well as our fish "roster":

Aquarium Water: 1 ppm ammonia, 0 ppm nitrite, 5 ppm nitrate, 7.4 pH
Water Source (treat w/ Prime & sits for at least 24 hours before adding to tank): 0 ppm ammonia, 0 ppm nitrite, 0 ppm nitrate, 7.4 pH
5 Black/White skirt tetras
6 Mollies
1 Guppy (the sole male; all the ladies are in our 20 gallon)
Various babies (3 mollies & a surprise tetra baby that was discovered yesterday)
2 Tiger Snails
1 Assassin snail
Fluval 50 filter with biosponge, ammonia remover & biomax
Aqueon Pro 100 watt heater
20 watt/60 volt florescent light bar that is on for about 10 hours a day, plus the tank has access to indirect natural sunlight
4 Live plants (Amazon Sword, Ludwigia Repens & 2 Aponogeton Ulvaceus)


Ammonia remover may have starved the beneficial bacteria and caused a minI cycle . No need for ammonia remover if you properly cycled the tank. Not sure why or how you are using the ammonia remover.

You mention using Stability... Did you do fishless cycle? What was your ammonia source? Ammonia from a bottle, or (rotting) fish food?.
  • Thread Starter


I put the ammonia remover filter stage in after the carbon had been running for a week because that is the filter medium I have used in our other tank successfully for a while.

I started the tank with rotted food, fishless, and with the Stability to speed up the cycling process. I'm thinking the Stability was a mistake, but hindsight is 20-20 and there's nothing I can do about that now.

After testing for ammonia and nitrite in the first week, I added a black skirt tetra, and then added two more a few days later. About a week after that I introduced my other two tetras, and slowly over the next week or so added the original 4 mollies that I had. I tested the water 2-3 times a day and did a water change whenever necessary while introducing the fish, and in the weeks that followed.

All the fish have successfully been in the tank for 4 weeks or so, and the ammonia is still holding steady at 1 ppm/somewhere between .05-.19 ppm free ammonia.


Using Stability wasn't the issue here, using the ammonia reducer was.

A fishless cycle takes about 6 to 8 weeks (sometimes more). Adding fish one week after starting up the tank, you basically did a fish in cycle. Stability works well, I use it all the time when starting new tanks or adding lots of new fish to an existing (QT) tank. In your case, Just keep dosing it until your ammonia and nitrites go up amd back down to 0, dose Prime too to neutralize the free ammonia for up to 24 hrs.

I do not like adding fish food to start a tank because you cannot accurately measure how much ammonia you are adding. Using bottled ammonia is the best way to do a fishless cycle. With stability, Tetra SafeStart, etc, you can only add about 2 ppm of ammonia otherwise you overwhelm the bottled bacteria and get ammonia spikes. Using rotting food is also bad because it can lead to water mold (fungus) taking hold in your tank.

Have you tested your tap water? If you have chloramine (chlorine + ammonia) in your water supply then it will show up as ammonia in the tests.
  • Thread Starter


Ah, so the filter media that I thought would help is what ended up possibly throwing off my tank. Figures. Guess I'll put a new carbon stage in for the time being and pull out the ammonia remover.

So when I used Stability in the beginning, I followed the instructions and did a double dose to start, and then a single dose for the rest of the week. Should I do this regimen again, or just do a single dose daily until the ammonia and nitrites spike and then go back down?

As far as our water source, it has been tested multiple times, both as it is coming out and after sitting for 24 hours. It consistently reads as 0 ppm for ammonia, nitrite and nitrate. We actually are unable to use our tap water as it has 40 nitrates, and goes through a water softener which reduces the gH to 0 (yet the kH is 9, which is the complete opposite end of the spectrum). So I haul water home from my family farm in our backyard, which has a different water source, and seems to have perfect parameters for our tank. Both gH and kH are right in the middle (4-5), and as previously stated, there is no ammonia, nitrite or nitrate.

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