I messed up my tank

[Rita]

You guys! I somehow messed up my tank. There’s been a lot going on with this tank lately so it could be any number of things… I added new stock, added new gravel on top of my eco complete, treated with expel-p for a suspected parasite in a fish, so yes. I’m fully aware I brought this in myself…

My question is has anyone had nitrites this high and have their fish act completely normal? Because the only reason I tested my tank to start with was to see if my nitrates were high enough for my plants. I saw the pink on the aquarium co op test strips and that prompted me to bust out the master kit. 

I did a 50% water change yesterday when I discovered this and tested the water again today and everything looks almost the same… so I did another 50% water change today…. Even though my fish look happy as can be.

Here’s pics of the tank in question and my test kit results for fun.

[PerceptivePesce]

I just went through a new tank cycle, 90g.  The 2-dozen female & 1 male guppies experienced 11 days of danger zone nitrites (aco test strips).  They showed no signs of distress.  However, I read that nitrite poisoning could take some time to express itself.  My nitrites have been in the safe zone for about 2 weeks and the guppies are growing and giving birth.  Actually, they never stopped reproducing!

I've been doing ~22% WC once a week. During the nitrite spike, I did 2 extra 22% WC.  It did nothing to lower the nitrites.  My goal was to cycle the tank so I just rode it out instead of doing full WC.

[AndEEss]

Do a 50-75% water change, immediately.

[Comradovich]

Misread your post. I was looking at your nitrates and thinking: "Well, that's not too bad in a planted tank. They'll remove a bunch of that over the week..." And then I realized you mean the purple nitrite amount. Yeah, seems I've come down with a terminal case of "Old". Sadly there appears to be no cure. Sir Terry was correct about life being a drug.

To your question, let's run down the list of what you did.

First, you've got two colonies in your biological filter: You have nitrosomonas which processes Ammonia, then you've got Nitrobacter which processes nitrite. Nitrosomonas has a single flagellum and moves. Nitrobacter is sedentary. Generally, Nitrosomonas does the colonizing, and creates or expands the biofilm that Nitrobacter then lives on. If the word "biofilm" is unfamiliar, lift the lid on your toilet tank and look for a spiderwebby substance. That's biofilm, it's what composes the portion of your biological filter in whatever type of actual filter you have. Bentley Pascoe just did a YouTube video this week on filtration, which explains a bit about where your biological filter lives in the tank. (Spoiler: Everywhere).

1. You increased the bioload by adding fish. Situation normal, you just need to wait a bit until your biological filter has upcycled by breeding more bacteria to handle the increased load. In the meantime - you water change.

2. You then added gravel. One of the places your biological filter lives is the substrate. So if you removed any old substrate, you reduced the filter a bit. If not, you buried it a bit. Either way the solution is giving it time to adapt and fully colonize the new gravel. I would aggressively avoid doing any gravel vaccing while you let it settle in. Overcleaning here would be counter-productive.

3. Expel-P is an anti-parasite medication. It's hunting bigger prey than your bacteria. I'm assuming the P is standing for praziquantol, which is a pretty standard fish de-wormer. (It's in Prazi-Pro, General Cure, etc.) Maybe that'll stress the bacteria, but it shouldn't wholesale kill it off. *However* one of the steps to using Expel-P was to remove your filter cartridge. "Remove Carbon or other chemical filtration during treatment". You'll never guess what was living on that filter cartridge... yeah, a portion of the biological filter. You probably reduced it again.

 

So you've taken three steps in a row to stress and reduce the bacteria. They're trying to breed fast enough to keep up with you, but they're only so fast. That nitrite level will trend downward, but they've gotta have time to eat and reproduce. Remedial steps would be "as you feel necessary" water changes. @PerceptivePesceis probably right about riding some of it out. If the fish aren't showing signs of additional sickness, they might be fine. Those extra water changes are also reducing the effectiveness of your Expel-P. You might want to stop for a bit on that treatment until you stabilize, or plan on having to treat a little bit longer if the parasites are that bad. Having nitrite in the tank in some quantity will probably stimulate the Nitrobacter to reproduce, there's food everywhere now. That's going to be useful in the long-run to keep up with the load from those extra fish.

Now, the current health of your colonies is looking fairly good for Nitrosomonas. That's what's making all the nitrites. You'll notice your ammonia is low, so they're eating aggressively. But again, we need it to be cranking out the biofilm for your Nitrobacter colony to live on. The best thing you can do here is leave the substrate, filter, furniture, glass, and plants all *uncleaned* until the test comes back better. Keep any OCD in check during a water change and just do water in, water out. When you're stable again, then go cleaning surfaces the bacteria live on.

[Rita]

On 11/17/2022 at 8:15 PM, Comradovich said:

Misread your post. I was looking at your nitrates and thinking: "Well, that's not too bad in a planted tank. They'll remove a bunch of that over the week..." And then I realized you mean the purple nitrite amount. Yeah, seems I've come down with a terminal case of "Old". Sadly there appears to be no cure. Sir Terry was correct about life being a drug.

To your question, let's run down the list of what you did.

First, you've got two colonies in your biological filter: You have nitrosomonas which processes Ammonia, then you've got Nitrobacter which processes nitrite. Nitrosomonas has a single flagellum and moves. Nitrobacter is sedentary. Generally, Nitrosomonas does the colonizing, and creates or expands the biofilm that Nitrobacter then lives on. If the word "biofilm" is unfamiliar, lift the lid on your toilet tank and look for a spiderwebby substance. That's biofilm, it's what composes the portion of your biological filter in whatever type of actual filter you have. Bentley Pascoe just did a YouTube video this week on filtration, which explains a bit about where your biological filter lives in the tank. (Spoiler: Everywhere).

1. You increased the bioload by adding fish. Situation normal, you just need to wait a bit until your biological filter has upcycled by breeding more bacteria to handle the increased load. In the meantime - you water change.

2. You then added gravel. One of the places your biological filter lives is the substrate. So if you removed any old substrate, you reduced the filter a bit. If not, you buried it a bit. Either way the solution is giving it time to adapt and fully colonize the new gravel. I would aggressively avoid doing any gravel vaccing while you let it settle in. Overcleaning here would be counter-productive.

3. Expel-P is an anti-parasite medication. It's hunting bigger prey than your bacteria. I'm assuming the P is standing for praziquantol, which is a pretty standard fish de-wormer. (It's in Prazi-Pro, General Cure, etc.) Maybe that'll stress the bacteria, but it shouldn't wholesale kill it off. *However* one of the steps to using Expel-P was to remove your filter cartridge. "Remove Carbon or other chemical filtration during treatment". You'll never guess what was living on that filter cartridge... yeah, a portion of the biological filter. You probably reduced it again.

 

So you've taken three steps in a row to stress and reduce the bacteria. They're trying to breed fast enough to keep up with you, but they're only so fast. That nitrite level will trend downward, but they've gotta have time to eat and reproduce. Remedial steps would be "as you feel necessary" water changes. @PerceptivePesceis probably right about riding some of it out. If the fish aren't showing signs of additional sickness, they might be fine. Those extra water changes are also reducing the effectiveness of your Expel-P. You might want to stop for a bit on that treatment until you stabilize, or plan on having to treat a little bit longer if the parasites are that bad. Having nitrite in the tank in some quantity will probably stimulate the Nitrobacter to reproduce, there's food everywhere now. That's going to be useful in the long-run to keep up with the load from those extra fish.

Now, the current health of your colonies is looking fairly good for Nitrosomonas. That's what's making all the nitrites. You'll notice your ammonia is low, so they're eating aggressively. But again, we need it to be cranking out the biofilm for your Nitrobacter colony to live on. The best thing you can do here is leave the substrate, filter, furniture, glass, and plants all *uncleaned* until the test comes back better. Keep any OCD in check during a water change and just do water in, water out. When you're stable again, then go cleaning surfaces the bacteria live on.

Thank you so much for this extremely detailed break down! What you say makes perfect sense. However I only run a sponge filter and an air stone, so it hasnt been removed during the expel-P treatment. Also this tank is a year old in January so I’m surprised this has happened. I think the gravel could very well be the main culprit.

[PerceptivePesce]

Maybe try adding some starter enzymes.  I used those products while cycling.