Nitrites High, Cycle weirdness

Hello everyone,

First post and hoping this group can help me figure out my 20 gallon tank. Its had an interesting story, and everything that could go wrong with it has gone wrong. Short preface on it, I got into fishkeeping along with my youngest because she won a goldfish back in Sept 2022. We started off with a 5 gallon. After having some bad luck with that, we upgraded to a 20 gallon in November 2022, as a bigger tank is easier to keep stable, or so we thought. We made a bunch of novice mistakes, and after understanding the nitrogen cycle, we felt terrible for putting those fish through a brutal fish-in cycle.

The 20 gallon would take about a month and a half to complete its cycle. After 6 weeks and a few lost fish, we woke up one day on 12/18/2022, to 0 nitrites, 0 ammonia, and 40 nitrates. The tank would stay stable and we'd have 0 on all the bad stuff, but our nitrates were slowly going up. I did 25% water change after we saw those nitrates going up to keep them in check. I should also add, that once those levels came down, I had 2 fish that got sick in the tank during the initial cycle (one guppy and one molly), and I pulled them out and put them in a quarantine tank until the cycle finished. Everything finished up, and I moved one of those fish back into the 20 gallon. The other had to stay in quarantine because it was a female and we didn't want to deal with baby fish lol.

We wanted to keep up our bioload, so we went out a week after the tank cycled and bought 2 more guppies. A week after we added the guppies things were still stable, then one day I noticed we had a missing guppy. I looked all over the tank and couldn't find him, which triggered me to execute a cleaning up the tank (I know now it was a bad idea to do that). The fish wasn't in the tank, and we found that he had jumped out of the tank and landed on the floor behind the tank, which made me feel really terrible about the cleaning I had done, which involved: vacuuming all the gravel (just the surface), rinsing the filter media in OLD TANK WATER (a lot of people assume I used tap).

The levels bumped up in the 20 gallon, to .25 amm, .25 nitrite, but they were still converting. Confident that the tank would eventually zero out again, we replaced the jumper with another guppy. Tank zero'ed out like I thought it would, and then a few days later, I noticed the fish were acting really stressed out one morning. I did a full test of everything, and found out my PH crashed over night, a full point. I was using aragonite to stabilize the PH and it was hanging at 7.8, until that morning where it dropped to 6.0 - 6.2! The only thing that would've caused that would've been a piece of driftwood we got from the pet store, that might have been decaying. I pulled it out of there and replaced it with a lava rock.

After that PH crash which happened the week after New Years (I think 1/4/2023), my levels started to go crazy. I had to replace the aragonite, so I added more to the tank to stabilize the PH. Ammonia was at .50, and Nitrites were at 1.0. This would start the daily 50% water changes. I could keep the levels down with the changes, but the nitrites would just creep back up. Eventually they started registering to the 2.0 - 5.0 ppm range. So, ever since then, I've been doing 50% water changes up until this past Monday 1/23.

This is where it gets really weird and frustrating. Last week, my nitrites started to go down, and dropped to .25 on Friday, but then on Saturday morning they shot back up to 1.0ppm and are now back up to 2.0 - 5.0ppm. I'm not sure whats going on with it anymore.

I've gone through the gauntlet with the bottled bacteria's. I've used just about all of them except for Dr. Tims. Throughout this 20 gallon's cycle I've been adding bacteria everyday up until last Monday... I noticed results after I stopped doing that, until things spiked back up on Saturday with the nitrites.

The tank has a lot of live plants, 2 lava rocks, 3 mollies and 3 guppies, and their decorations. There's gravel in there and some aragonite crushed coral. Right now, the levels are at 0 - .25 ammonia, 2.0 - 5.0 nitrites, 40 nitrates, 7.8ph. I don't know how to get those nitrites down anymore. Nothing indicated a cycle crash as I never lost the nitrates. I've even upgraded to a Fluval 207 canister filter thinking that my HOB filter was not doing its job. I've had a decent filter on there this whole time, Topfins version of the Fluval Aquaclear, which has 3 chambers for different media. I just moved things to the new filter and the cycle didn't really lose a step despite everything going on.

I'm assuming that big cleaning I did before to find that guppy screwed some things up, and that weird PH crash didn't help things either. We want to reset the tank and start over, but we can't because of our friends in there who've been through a lot. But either way, I'm stuck with really high nitrites, the water changes are starting to get expensive with my water bill, and I don't know what to do anymore to get them down other than to wait it out.

The other interesting part is this: I had to setup a 10 gallon tank for my female molly. I got it for Christmas, and got it all setup, and added 5 white skirt tetras. I used Microbe-Life Special Blend and Nite Out II, and that thing took a week to cycle. I put the female molly in there, and for 3 weeks, without doing anything to tank other than weekly 25% water changes, the levels stay zero'ed out except for my nitrates. So, at least I know I don't have a black thumb for fishkeeping.

The products and routine for the 20 gallon are as follows:
Seachem Prime to dechlorinate the water and protect the fish
Seachem Stability (initially used to cycle the tank)
Microbe-Lift Special Blend and Nite Out II (started to use these when the levels spiked)
Fluval bottled bacteria (not sure of its exact name, but gave this a shot. No change)
Fritzyem 7 (Tried it, no change)
Stayed on Nite Out II for a while but still no changes
Now back onto Stability with no changes in site on the Nitrites

After each water change I add Stability or whatever I have on hand. Right now, I'm sticking with Stability. I always dechlorinate, and whenever levels get high, I add Prime to protect the fish. As of this morning, I have a sick molly in there now, but the rest look OK. Nitrites are still high at 1.0 - 2.0 I think. I'm starting to think something is leaching nitrites into the tank but not sure what it could be other than the decor. I really want to reset this thing, but as I said before, I have fish in there and obviously can't just get rid of them. I've scoured the internet, but all signs point to my cycle should have recovered by now. I'm now worrying about the well being for the fish, and I feel horrible. Last night I bought a sponge 2nd sponge filter for my 10 gallon and I'm hoping to seed it over the next 2 weeks to see if that will help out my 20 gallon. I'm hoping someone can at least tell me what to do with myself when it comes to this tank as I feel like I'm out of options other than changing the water.

 

What's your base water readings from your source water? Also what is it after 24 hours when u let it sit?
Cut back or stop the constant stability dosing. People have reported elevated levels of nitrites when dosing with it. I don't think Stability claims to have Nitrospira type of bacteria. These are the ones that oxidize nitrite to nitrate. You might be over burdening with it. Continue detoxifying and WC's until the other phase of bacteria catches up.

 

Before I would add any decorations or rocks or wood to my tanks I would stick them in a bucket with water for a week or so and then check the water, looking for ph changes or anything else before they got to go into the tank. 3 mollies and 3 guppies is not a huge of a bioload for a 20 gallon planted tank, if it was me I would pull the decor leaving the plants, slow down with all the chemical adds and just do water changes if numbers get too far out of line and see if things start to level out, also maybe feed the fish every 3rd day just to slow down the production of ammonia.

 

What's your base water readings from your source water? Also what is it after 24 hours when u let it sit?
Cut back or stop the constant stability dosing. People have reported elevated levels of nitrites when dosing with it. I don't think Stability claims to have Nitrospira type of bacteria. These are the ones that oxidize nitrite to nitrate. You might be over burdening with it. Continue detoxifying and WC's until the other phase of bacteria catches up.

Yeah, I tested those early on lol. Small amount of ammonia (0 - .25), 0 nitrites, 0 nitrates, not sure on the PH. I have not let the tap sit out for 24 hours and tested, but I'll check tomorrow afternoon.

I'll continue with some water changes if the levels get out of hand. I have stopped dosing with the bacteria as of the weekend of the 20th. Thats the weird thing, last week, I had a downward trend and hit .25 nitrites. I was expecting it to 0 out the next day, but then it hit 1.0ppm. I didn't start lobbing bacteria in there again lol, I've just been detoxing the water and changing it. From what I can tell the nitrite eating bacteria just needs to catch up to the other stuff, but making sure nothing is leaching in there.

I'm starting to learn that while they say "you can't overdose on bacteria", I think you can. Definitely seems out of balance. Ironically, my 10 gallon tank is fully cycled and very self-sufficient. I only add a small dose of Stability when I do a water change.

Before I would add any decorations or rocks or wood to my tanks I would stick them in a bucket with water for a week or so and then check the water, looking for ph changes or anything else before they got to go into the tank. 3 mollies and 3 guppies is not a huge of a bioload for a 20 gallon planted tank, if it was me I would pull the decor leaving the plants, slow down with all the chemical adds and just do water changes if numbers get too far out of line and see if things start to level out, also maybe feed the fish every 3rd day just to slow down the production of ammonia.

Yeah I've stopped with the bacteria for almost a week and a half now. See my reply to the thread as to what happened... but the summary is, had a downward trend, almost 0'd out, then a spike back up to 1ppm the next day. It was soul crushing lol, but still determined to get this thing fixed.

Yeah I didn't think that bioload was all that large. Once it balances out, our plan was to up the number of guppies to 6 or 7. But obviously, thats on hold now. I don't that far with adding decor. I usually just let them soak for a night in a bucket of detoxed water, and then I do water change, rinse off in old tank water, then add to the tank.

My ammonia has been good throughout this ordeal with only one spike at the beginning up to .50 - 1.0 but it came down pretty quick. All the other levels look OK, except those darn nitrites. I'm going to keep up with the water changes, but I can definitely see where these bottled bacteria products are hurting the tank at this point in the cycle.

 

Your ammonia numbers can be good but any ammonia produced gets converted to nitrites and a different bacteria has to convert it to nitrate, that's why I suggested doing something to reduce the amount of ammonia created in the first place to see if that would help reduce your nitrites until the bacteria needed to convert the nitrites to nitrates get caught up.

 

Your ammonia numbers can be good but any ammonia produced gets converted to nitrites and a different bacteria has to convert it to nitrate, that's why I suggested doing something to reduce the amount of ammonia created in the first place to see if that would help reduce your nitrites until the bacteria needed to convert the nitrites to nitrates get caught up.

Yeah, I've started slowing down the feedings. Probably once every 2-3 days until it catches up. I figured that might be part of the cause. I'll let you know how things pan out over the next week or so.

 

Hey Everyone,

Thought I'd give you an update. I'm not celebrating yet as I'm waiting to see how things are in the morning. But, I think we figured things out. I give credit to my wife for suggesting this, as I was in denial due to my daughter picking out the decor for the tank. So, yesterday, my wife suggested taking the decorations out of the tank. I told her the lava rocks are out of the question as they're giving me a lot of surface area for bacteria, and I also cleaned those things pretty well, and made soaked them in treated water for a few days before adding them into the tank.

The resin houses my daughter picked out from PetCo were removed. She understood why that was happening. Well, 6 hours after I removed them, I noticed a very slight change in the nitrites, but still between 1 - 2ppm. This morning, I was at .50 - 1ppm. By this evening I was at a solid .50ppm. The water level dipped in the tank, and I figured I'd do a small water change. I changed out 20% and added a cap full of Stability like I normally with a water change (first dose in 2 weeks). Tested 3 hours later and now, I'm between 0 - .25ppm nitrites, however, curious what the morning brings.

I thought about this while driving my son to his activity tonight (Civil Air Patrol if you're curious lol), and discussing the tank with him as he was curious what was going on. A little bit of a side note here but it relates.... I have a 5 gallon tank I've retired. I thought it was completely hosed up because I had ... thats right you guessed it, a nitrite spike in the tank. Nothing I did seemed to make it go down. I thought it was a filtration issue because it was our first tank and I just used everything from the starter kit. That tank housed my female molly and a snail, but I couldn't figure out why nitrites were 2ppm - 5ppm. Water changes had no effect; basically the same scenario. When this was happening with the 5 gallon, the 20 gallon started to have this same issue... this has been going on since 1/1/2023 (happy new year fish! have some high nitrites!).

So, doing some research, and it was hard to find information on this, I've learned that some cheaply made resin decorations will have paint that contains an anti-corrosion component to it. And, that typically contains sodium nitrite and potassium nitrite. It will release nitrites into the tank but in small amounts that are usually easy to deal with, but sometimes it leaches faster.

My 10 gallon tank has no decor from Petco, and has all Petsmart stuff in it (only a fake rock shelf and cave, and a crashed WWII plane), and that ones doing just fine. Water has been perfect for a month.

So.... I believe my culprit was some poorly made ornaments. But needless to say, I won't be buying really anything from Petco. We're tracking down some new ornaments, looking into Penn-Plax stuff or a couple of things from Petsmart. I'm going to vet them out a bit more and let them soak while the tank stabilizes, and will add them as long as I don't see any nitrite build ups in the buckets I put them in.

Thanks everyone for the advice and for helping me with this. For the record, I did everything we discussed here and had no level changes at all, so had to start eliminating things out of the tank to see where the leaching was coming from.... and it was the decor =/

Makes me wonder how many people go through this but don't suspect their ornaments, and simply give up and think they have a black thumb for fishkeeping. Lesson learned... clean them more thoroughly, test the water in a quaratined environment, and if I see nitrites, take 'em back.

I'm anticipating the nitrite levels will drop more steadily now, and return to a stable state. But, we'll see how things are in the morning and over the next couple of days.

 

As long as shops sell those ornaments along with Seachem stability, Microbe-Lift Special Blend, Nite Out II, Fluval bottled bacteria, and Fritzyem 7, I think the answer to your question is "the majority".

While all you needed was dechlorinated water, oxygen, dim lights, a few fish, and a bit of patience .

 

Yep....what ruud said.

Each one of those bottles of "magic cycle potion" have various strains of bacteria.

There's a lot of nitrosomonas, nitrobacter, and nitrospira bacteria species. They are all probably in there competing.

I know it might sound hard but you gotta keep your hands outta that tank and let it stabilize.

That bacteria needs to grow on all of those things in the tank and if you are constantly removing stuff and cleaning stuff you are disturbing that bacteria colony.

I recommend only water changes and Prime.
Don't touch the decor the substrate or the filter for the next 2 months.

Just test test test and keep those toxins diluted with water changes. Don't be scared to do big water changes either.

Keep your total combined ammonia and nitrite levels below 1ppm at all times.

Just be consistent and let everything establish and stabilize.

It will happen, I promise. You're doing great.

 

Final update for this scenario! Happy to report that nitrites went down steadily since removing the offending decorations. Cycle is starting to stabilize again, and nitrites are almost to 0. I anticipate that nitrite test giving me that pretty blue color I get from my 10 gallon, at some point tomorrow or Sunday.

What sucks with the 20 is it had just completed its cycle and was 3 weeks into maturing before all this happened (the month and a half long spike). Live and learn... and at least things are stabilizing again.

Going to let these tanks age for the next few months before I crank up a 40 gallon. Thanks again guys for the great advice! Really glad I joined this group.

 

You could cycle the 40 gallon with only the filter and substrate (and plants if applicable) . Then add the decor later.

That way if you feel the urge to rearrange stuff or take stuff out... it will have little to no effect on your newly established bacteria colony as long as you leave the filter and substrate alone for the first few months.

But if you cycle the aquarium with the spongebob house, bacteria will grow on the spongebob house. Then when you decide that you don't like the spongebob house and take it out...you are also taking out good bacteria.

 

You could cycle the 40 gallon with only the filter and substrate (and plants if applicable) . Then add the decor later.

That way if you feel the urge to rearrange stuff or take stuff out... it will have little to no effect on your newly established bacteria colony as long as you leave the filter and substrate alone for the first few months.

But if you cycle the aquarium with the spongebob house, bacteria will grow on the spongebob house. Then when you decide that you don't like the spongebob house and take it out...you are also taking out good bacteria.

Yeah LOL, thats the level we want to get to, where we can leverage the established tanks to start up the new one(s). And no spongebob houses here ! My daughter setup a cool looking gnome village in the tank. She was a little heart broken to learn they were causing the problems in the tank this week. But, we went to another store where we've bought decor before and had no issues. Choices were limited, but we were confident with their quality.

Nice thing with the 20 gallon, is now its basically cycled without the decor. Only a pair of lava rocks which is what I want the bacteria to grow on.

Also just for anyone curious..... Nitrites tested that pretty blue color today, 0 ppm.