Nitrites not going down after many consecutive large water changes

[Artifact]

I've been following Eco23's fishless cycling guide here: https://www.aquariumadvice.com/foru...guide-and-faq-to-fishless-cycling-148283.html


and I've been stuck on getting my nitrites to go down, I'm one month into the cycle. (ammonia cycles within 12 hours, but nitrites stay at max measurable level and don't move). After reading and re-reading the guide, I thought perhaps I never really got my nitrites down to a readable level as suggested even though I did a large (60%) partial water change at the point the guide suggested. I thought perhaps more and larger water changes would get it down to a readable level.



Testing my tap water both before and after adding dechlorinator its base nitrite level is always 0 ppm.



Tonight (perhaps inadvisably) I've done 4 water changes, the largest one probably about 80%. Each time, after adding the new dechlorinated water and waiting 20 minutes for it settle and go through the filter, the nitrite level is always over 5ppm (the max my API test kit can measure). I'm having trouble understanding how several very large consecutive water changes with 0 ppm water could always result in a 5ppm result several minutes later.



Is my tank's water just ultra-concentrated with nitrites, so that when the vast majority of it is replaced with 0ppm nitrite water it's still going to be over 5ppm?



It's a 6 gallon nano tank, and I worry that even when the bacteria to process the nitrites colonizes, it won't be able to handle such a high concentration that no amount of water changes can reduce.



My PH is 7, ammonia process from about 4 to 0 in less than a day, and water temperature is 85.



Thank you for any advice.

 

[Enchantress]

I'm assuming the tank has a filter? Maybe the test is defective? Swinging from 0 to unreadable is sometimes due to a problem with the test, so might be worth considering getting a "second opinion" from a different kit. 4ppm ammonia is ridiculously high. Anything above that (5 or 6 ppm) can actually end up killing even the beneficial bacteria, and very high levels may inhibit the growth of the colony. In your case - assuming the test kit is fine - it sounds as if the ammonia-eating bacteria are already doing fine, but the ones responsible for consuming nitrites haven't established themselves yet. Once nitrites are present, they should start growing and bringing down the levels. If you want (and if you're able to), you can buy them and add them separately. I don't think it could do any harm, and it might just solve the problem. It might also be a good idea to add some fast-growing live plants to the tank; they're nitrogen guzzlers and should help bring down the levels.

Also, any particular reason why the temperature is so high?

 

[Dallascowboys16]

Is your test kit expired? It is rare to ever have nitrites that high even while cycling. If you want my honest opinion, fish in cycling in the way to go and is totally safe and humane for the animals if done the right way. Usually I just add a few fish at a time slowly building up the population with around a week or two between new additions. Never lost fish during cycling and saves you the headache of all the testing and manual ammonia dosing. I would get a new test kit, let the tank sit for a few days to a week and test the water. If ammonia and nitrite are low enough (0-0.2 ammonia 0-0.1 nitrite) I would go ahead and add a few hardy fish to start. I cannot tell you how many people I have seen have a cycle stall out like this and give whacky parameter readings. Save yourself the trouble and just get the water within reasonable parameter ranges and get some fish.

 

[Artifact]

All of the advice (temperature and ppm for ammonia) I have been following from eco23's guide I linked. All of the guides I've read say to keep the temp between 82-85 for the cycle during a fishless cycle to help the bacteria grow quickly, and lower it to the ideal temperature of the animals once the cycle is complete. I've also read a lot of contradictory info from people who said they've cycle their tank one way or another successfully (while strongly condemning every other method's chemical levels or parameters) so it's hard to know exactly what to do after looking online for weeks as many guides contradict each other.



My test kit doesn't expire for 2 years (API master kit), I will look for an individual nitrite kit and see if the readings are different.



If my nitrite doesn't go below 5ppm even with almost full water changes with 0ppm nitrite water, I don't know how I can get it to a safe enough level to do a fish-in cycle. I recently bought a bottle of seachem prime which claims to detoxify nitrites and allow the bio filter to take care of them, I will see if anything comes of it.



Originally I didn't want any fish, just invertebrates, but if a fish-in cycle ends up being the only viable option it's something I will try. What hardy fish would be recommended for a 6 gallon tank? I would think they would need to be very small fish for them to be comfortable in such a small tank.



I use a sponge filter that has a ceramic media holder attached that the water runs through. I've recently acquired some used ceramic filter media by trading away my excess java moss so perhaps that will have some positive effect.

 

[Aiken Drum]

I would like to add that every 1ppm of ammonia you add will turn into 2.7ppm of nitrite so 4ppm will equate to over 10ppm of nitrite. 4ppm of ammonia is way more than a heavily stocked aquarium will produce in a 24 hour period. 1ppm in 24 hours would be a normal amount for a moderately stocked tank. So i wouldnt worry about your systems ability to filter out the nitrite just yet because your stocking isnt likely to produce anywhere near the amount it currently is.

If those nitrites have been allowed to build up over a few days then it could take a lot of water changes for it to dilute down to a readable level.

Its normal to reduce the ammonia input down to 1 or 2ppm after the initial dose of 4ppm has cycled out to avoid this very situation. I would maybe even drop down to 0.5ppm dosing given how good a colony of nitrosomonas bacteria you now have.

Incidentally, do you have a reading on nitrates? If that is rising it should give you a feeling on how much of your nitrites are actually going to nitrates (1ppm ammonia to 2.7ppm nitrite to 3.5ppm nitrate for a fully cycling aquarium - presuming nothing else is acting on it, like plants).

 

[Artifact]

I would like to add that every 1ppm of ammonia you add will turn into 2.7ppm of nitrite so 4ppm will equate to over 10ppm of nitrite. 4ppm of ammonia is way more than a heavily stocked aquarium will produce in a 24 hour period. 1ppm in 24 hours would be a normal amount for a moderately stocked tank. So i wouldnt worry about your systems ability to filter out the nitrite just yet because your stocking isnt likely to produce anywhere near the amount it currently is.

If those nitrites have been allowed to build up over a few days then it could take a lot of water changes for it to dilute down to a readable level.

Its normal to reduce the ammonia input down to 1 or 2ppm after the initial dose of 4ppm has cycled out to avoid this very situation. I would maybe even drop down to 0.5ppm dosing given how good a colony of nitrosomonas bacteria you now have.

Incidentally, do you have a reading on nitrates? If that is rising it should give you a feeling on how much of your nitrites are actually going to nitrates (1ppm ammonia to 2.7ppm nitrite to 3.5ppm nitrate for a fully cycling aquarium - presuming nothing else is acting on it, like plants).

Thank you for your response. One large problem I'm having is that even when doing huge water changes (~80%) to reduce the nitrite level, as soon as I measure the levels after letting it sit for about 20 minutes they are immediately 5ppm after adding new water and not adding any ammonia, and the tap water I'm using has less than 1ppm ammonia and 0 nitrites as of testing yesterday.



That is good advice to lower the amount of ammonia I'm adding and one I hadn't considered, however, I do worry that my ammonia processing bacteria will starve. It's able to process 4ppm to 0ppm in less than 10 hours now, if I don't constantly add some ammonia for it to process, won't it die? How long can it go with no ammonia? My thinking is that if I only add a little ammonia, it will process it all within a couple of hours and end up starving. I do have a small amount of java moss in the tank as well.



When I first added the moss I did notice it completely removed all nitrates from my tank in one night. From 40-80ppm to 0 overnight which was shocking (after that it sort of grew out of control). I have since removed some of it as it was way too much moss for my tiny tank, but I am sure the amount I have still has an affect on nitrate levels.



Testing nitrAtes now, they are 5ppm. Nitrites are still the max level the API master kit can show (5ppm).

 

[Aiken Drum]

I wouldnt worry about starving the bacteria in the short term, especially as it seems to be such a strong colony and you dont really need it to be cycling out 4ppm in 10 hours. As long as its kept oxygenated with water running through the filter it won't start to die off in significant quantities for several weeks. It just goes into a kind of dormant state and reanimates when the food source appears again. If it drags on and you arent dosing anything, then you might need to do something.

My cycle on my 200 litre had about a month with sky high nitrites, so yours isnt unusual.

I would also consider what Dallascowboys says. Your system is cycling to some degree, might even be a very strong cycle as we dont really how much nitrite is being consumed. Even if you was opposed to a fish in cycle, if you did get nitrite down to an acceptable level (maybe even a near 100% water change) you could stock a few fish.

Have you considered diluting a water sample down in the test tube (say 1 part tank water to 9 parts bottled water) and multiplying the result up accordingly so you can get an approximate nitrite reading for your tank water?

Edit. Also with regards to getting conflicting opinion. The hobby has more than one way to skin a cat and everyone will just be giving you what works for them and what fits into their moral compass. At least somewhere like here that opinion is backed up by some experience unlike some advice you might get from a pet store. Ultimately though, you have to make your own decisions and find something that works for you.

 

[Artifact]

I will look at doing a pretty massive water change soon with seachem prime as my conditioner, maybe more than once if my nitrites still go to max testable level immediately, and then lessening the amount and frequency of ammonia additions. In the past weeks no amount of water changes have been able to bring my nitrites down to a readable level but I have always left a few inches of water, and I'm sure the sponge filter retains a good portion of water but I wouldn't want to squeeze that out too much I'm guessing.

I don't have anything against fish in cycling, but my aquarium is small and set up with a large central decoration I custom drilled to fit with my heavy aeration stone and tubing (I only expected to have shrimp, maybe freshwater isopods, so lots of surfaces and hiding places), I hope there's enough room for a fish to swim around comfortably.

While cycling and growing the bacteria I'm currently using an adjustable heater that's made for 5-10 gallon tanks but does consume a lot of space, once I have everything established I do have a stick-style 78 degree 50w heater that will allow some more room. The filter is in the back of the tank, not visible from the bubbles.

 

[Artifact]

I would also consider what Dallascowboys says. Your system is cycling to some degree, might even be a very strong cycle as we dont really how much nitrite is being consumed. Even if you was opposed to a fish in cycle, if you did get nitrite down to an acceptable level (maybe even a near 100% water change) you could stock a few fish.

I did 2 almost complete water changes last night (even tilting the tank to get as much water as possible from the bottom). Immediately after adding new, dechlorinated water, the Nitrites were 0 and I thought about buying and adding fish the next day for a fish-in cycle. However, when I tested this morning, nitrites were between 2-5 ppm (it's hard to tell colors exactly at that level with the api kit).



Some of this I think has to do with my tap water naturally having ammonia in it, meaning that immediately it's going to start processing and turning to nitrite. Testing my tap water alone it's 1ppm ammonia.



Would adding an entire tank of water jugs from the grocery store be an option at this point? I would assume they have less ammonia than my tap water.

 

[Aiken Drum]

The ammonia in your tapwater is more than likely chloramine which some water companies use instead of chlorine. The API test kit for ammonia (assuming that what you are using) is in reality a test for chloramine (bottle #1 turns ammonia to chloramine and bottle #2 tests for chloramine). The chloramine will break down to ammonia and chlorine in your aquarium however and your filter will deal with the ammonia over time, but in the meantime your fish will be living in toxic conditions.

A few options.

- Bottled water as you suggest. Make sure it isnt distilled, demineralised, sparkling or flavoured.

- RO/DI water, either bought from the fish store or you can install your own system to produce your own from your tapwater. You will also need to remineralise it.

- You could get a cheaper carbon filter system for drinking water to remove chloramines.

- Use a water conditioner specifically formulated to deal with chloramine (like Seachem Prime). This in effect detoxifies the ammonia from the broken down chloramine while the filter deals with it. (Im not going down the rabbit hole of whether seachem lies about their products claims again. If you want to get into that PM me).

Bit of extra reading if you are interested.

https://www.thesprucepets.com/remove-chloramines-from-tap-water-2924183

 

[Artifact]

The ammonia in your tapwater is more than likely chloramine which some water companies use instead of chlorine. The API test kit for ammonia (assuming that what you are using) is in reality a test for chloramine (bottle #1 turns ammonia to chloramine and bottle #2 tests for chloramine). The chloramine will break down to ammonia and chlorine in your aquarium however and your filter will deal with the ammonia over time, but in the meantime your fish will be living in toxic conditions.

A few options.

- Bottled water as you suggest. Make sure it isnt distilled, demineralised, sparkling or flavoured.

- RO/DI water, either bought from the fish store or you can install your own system to produce your own from your tapwater. You will also need to remineralise it.

- You could get a cheaper carbon filter system for drinking water to remove chloramines.

- Use a water conditioner specifically formulated to deal with chloramine (like Seachem Prime). This in effect detoxifies the ammonia from the broken down chloramine while the filter deals with it. (Im not going down the rabbit hole of whether seachem lies about their products claims again. If you want to get into that PM me).

Bit of extra reading if you are interested.

https://www.thesprucepets.com/remove-chloramines-from-tap-water-2924183

Thank you for your continued help. As I couldn't find any cheap tapwater filters for chloramine specifically, I decided to try a Pur tapwater filter available locally. From some research it seems chlorine is easier and cheaper to remove but chloramine is not. After setting up the tapwater filter and letting it run 5 minutes as suggested in the manual, I tested both the filtered and unfiltered water with my api test kit for ammonia.



Both samples were the identical color, somewhere between 0.5 and 1 ppm. The filter itself says it filters chlorine so I hoped chloramine would be impacted to some minor extent, but I haven't been able to find a tap water filter that actually mentions chloramine or ammonia, only the several hundred dollar reverse osmosis filters mention it that I've seen. I could return this Pur filter and try activated carbon tap filters I see online made from coconut fibers for the activated carbon, which I have read on another site just breaks the chloramine apart, filtering the chlorine out of it and leaving you with ammonia. I've also read that choloramine requires extended contact with a carbon filter to really filter out, rather than just run through it like a tap filter (however that was on the page of a competing osmosis product so not sure how factual that is)



I do use seachem prime as my water conditioner. At this point it may just be best to wait and see what my tank does with little to no ammonia additions for a week, as nitrites are already near max readable levels less than 1 day after being 0 and no additional ammonia added.