High nitrites after daily water changes

[Ellithain]

Hey guys I need help, I have a tank newly established about two months old 20 gallon. I had thought it was fully cycled a month ago when ammonia 0 and nitrite 0 were at zero for several days. I had used old media from another tank of mine to try to speed up the cycling as well. I have 4 guppies, 5 neon tetras, a shrimp, and a bristlenose pleco in the tank along with about 35 week old guppy fry in a fry cage. For the past week or so I’ve been battling a nitrite spike and for the life of me I can’t figure out what’s causing it. I feed the fry and the adult fish twice a day. It is bare bottom so no places for food to get stuck and rot. I have java fern and moss that I thought would help with nitrites but obviously not enough. Nitrites have consistently been between .25-1. I’ve been doing daily 50% water changes. This morning after having done these changes for five days now it was at 1 and I immediately removed the fish and did a 100% water change. This brought it back down to blue (obviously) but then tonight I retested the water and it was back to a light purple so I did another 50% water change on top of the 100 I did this morning. What is going on?! I’m losing my mind! Ive had 4 tetras die on me at this point (idk how they go but I haven’t lost a single guppy fry) please help! What am I doing wrong?

[Potluck]

Originally Posted by Ellithain

Hey guys I need help, I have a tank newly established about two months old 20 gallon. I had thought it was fully cycled a month ago when ammonia 0 and nitrite 0 were at zero for several days. I had used old media from another tank of mine to try to speed up the cycling as well. I have 4 guppies, 5 neon tetras, a shrimp, and a bristlenose pleco in the tank along with about 35 week old guppy fry in a fry cage. For the past week or so I’ve been battling a nitrite spike and for the life of me I can’t figure out what’s causing it. I feed the fry and the adult fish twice a day. It is bare bottom so no places for food to get stuck and rot. I have java fern and moss that I thought would help with nitrites but obviously not enough. Nitrites have consistently been between .25-1. I’ve been doing daily 50% water changes. This morning after having done these changes for five days now it was at 1 and I immediately removed the fish and did a 100% water change. This brought it back down to blue (obviously) but then tonight I retested the water and it was back to a light purple so I did another 50% water change on top of the 100 I did this morning. What is going on?! I’m losing my mind! Ive had 4 tetras die on me at this point (idk how they go but I haven’t lost a single guppy fry) please help! What am I doing wrong?

What are your nitrates as that's when you know your tank is cycled or almost completed? Also 50% daily in my personal opinion is to much I would do 20-25% every day or every other day others will probably disagree and here's why, you're taking 50% of the water out and replacing it with new water meaning the water really never has a chance to cycle, if you do 50% daily it will take an extremely long time to do so, I would also use prime to condition the water you're putting back into the tank as prime detoxifies ammonia and nitrite to be less harmful to the fish.

what test kit are you using? And have you tested your tap water if not you should because the nitrite could be high in the tap (shouldn't be but it's possible), have you checked for a dead fish in the tank /filter as that will cause high nitrites, you Said its bare bottom what do you have the plants in? Because plants to if rotting /melting away will also cause nitrite spikes.

[coralbandit]

I would stick with 50-75% water changes when the nitrite gets to 1ppm.
+1 with using prime every other day[it last for 2 days] to help reduce the toxicity of nitrite.

[Potluck]

Originally Posted by coralbandit

I would stick with 50-75% water changes when the nitrite gets to 1ppm.
+1 with using prime every other day[it last for 2 days] to help reduce the toxicity of nitrite.

+1 Thanks for that CB I'm not as knowledgeable as you when it comes to these things so thank you for the confirmation of 50% everyday is what he should do, that way he doesn't lower to what I recommended and make it worse.

To the op listen to what Coralbandit recommended, disregard what I said about 20-25% but I would still test your source water, would still use prime as it's absolutely the best water conditioner out there, and please let us know what test kit you use and if you have any nitrates as well as your source water readings.

[Ellithain]

Originally Posted by Potluck

+1 Thanks for that CB I'm not as knowledgeable as you when it comes to these things so thank you for the confirmation of 50% everyday is what he should do, that way he doesn't lower to what I recommended and make it worse.

To the op listen to what Coralbandit recommended, disregard what I said about 20-25% but I would still test your source water, would still use prime as it's absolutely the best water conditioner out there, and please let us know what test kit you use and if you have any nitrates as well as your source water readings.

I am using API master test kit and I have tested my water as a control already and no no nitrites. My nitrates had consistently been around 5-10 is that too low to be cycled? I have been using a API tap water conditioner but I'll pick up some prime. Ugh I feel like such a bad person.. I thought it was cycled enough for the fish

[Ellithain]

Oh and I have the plants rooted to wood. Java fern is best not in substrate actually and the moss could even free float. Easy easy plants tbh. I did clean out the filter and no nothing and when I did the 100% water change I looked for dead fish and couldn't find any. Maybe I'm feeding the babies too much? I've been giving them a mix of baby brine shrimp, crushed peas, and egg yolk twice a day. It is pretty messy.

[Potluck]

Originally Posted by Ellithain

Oh and I have the plants rooted to wood. Java fern is best not in substrate actually and the moss could even free float. Easy easy plants tbh. I did clean out the filter and no nothing and when I did the 100% water change I looked for dead fish and couldn't find any. Maybe I'm feeding the babies too much? I've been giving them a mix of baby brine shrimp, crushed peas, and egg yolk twice a day. It is pretty messy.

Yes fern, anubias and a few others should not be rooted in the substrate you're correct, 5-10 is a sign that is cycled, so it sounds like the cycle crashed, do you have media in your filter (ceramic cylinders, bioballs, or anything that beneficial bacteria can grow on) or is the filter style you have just have a cartridge you throw out after a month? If this is the case that's probably how it crashed as when you throw that cartridge out you're basically throwing out your beneficial bacteria and with it being bare bottom and not substrate there's really no other big area for BB to grow, you can modify the filter and add ceramic media to it so when you change out the cartridge the ceramics stay in the filter and you don't lose your BB.


As far as feeling bad don't, but don't ever do a 100% water change at one time, you can do it safely over a course of several hours which is called a rank flush but by you cleaning you the filter I'm pretty sure you wiped out the beneficial bacteria which is what eats ammonia and nitrite.


I would keep to your feedings but I would reduce the amount you're feeding at one specific time, like take one feeding split it in 2 and just feed half and half if that makes sense, I'll give you an example say you feed 4 peas, a half cube of brine shrimp and an egg 2 times a day, I would cut that in half and feed half of that twice a day so in the morn 2 peas, 1/4 cube of brine and a half an egg in the morning and the other portion at night so yes it does sound like you're overfeeding a bit(this is just an example)

[Ellithain]

Originally Posted by Potluck

Yes fern, anubias and a few others should not be rooted in the substrate you're correct, 5-10 is a sign that is cycled, so it sounds like the cycle crashed, do you have media in your filter (ceramic cylinders, bioballs, or anything that beneficial bacteria can grow on) or is the filter style you have just have a cartridge you throw out after a month? If this is the case that's probably how it crashed as when you throw that cartridge out you're basically throwing out your beneficial bacteria and with it being bare bottom and not substrate there's really no other big area for BB to grow, you can modify the filter and add ceramic media to it so when you change out the cartridge the ceramics stay in the filter and you don't lose your BB.


As far as feeling bad don't, but don't ever do a 100% water change at one time, you can do it safely over a course of several hours which is called a rank flush but by you cleaning you the filter I'm pretty sure you wiped out the beneficial bacteria which is what eats ammonia and nitrite.


I would keep to your feedings but I would reduce the amount you're feeding at one specific time, like take one feeding split it in 2 and just feed half and half if that makes sense, I'll give you an example say you feed 4 peas, a half cube of brine shrimp and an egg 2 times a day, I would cut that in half and feed half of that twice a day so in the morn 2 peas, 1/4 cube of brine and a half an egg in the morning and the other portion at night so yes it does sound like you're overfeeding a bit(this is just an example)

I have a sponge in the filter and on the uptake I do not replace it to try to keep all those beneficial bacteria but yes I did just clean the filter out to try to make sure there wasn't a dead fish or rotten food in there and could have killed off the bacteria. I'll cut back on the food and keep up the 50% water changes. I wasn't aware that 100% change wasn't safe good to know! I thought all my water was bad so get rid of it right now or my fish would die.

[Potluck]

Originally Posted by Ellithain

I have a sponge in the filter and on the uptake I do not replace it to try to keep all those beneficial bacteria but yes I did just clean the filter out to try to make sure there wasn't a dead fish or rotten food in there and could have killed off the bacteria. I'll cut back on the food and keep up the 50% water changes. I wasn't aware that 100% change wasn't safe good to know! I thought all my water was bad so get rid of it right now or my fish would die.

No a 100% water change at one specific time is not good and should only be done in case of an emergency from what I've read and been told, like say someone accidentally dumps a chemical in it something like that, you can safely do a 100% but again from what I've read and been told it takes about 6-8 hours to do it safely, what filter do you have by chance?

Also don't worry about you cutting the food back a bit they're still getting fed just not as much so don't think you're starving them cause you're not, overfeeding leads to poor water conditions.

Also never clean the filter media with tap water, only clean it with tank water, you can clean the plastic pieces with regular water.

Reason I asked about the filter is you might not have enough filtration, probably not the case but I over filter the heck out if my tank.

[Potluck]

Just out of curiosity you don't use anything on the glass chemical wise do you?

Do you have an air pump if so is there any chemicals by it if so move them cause the air pump will suck the fumes In and distribute it inside the aquarium.

[Ellithain]

No I do not use anything for cleaning the inside I've used windex on the outside. As for the chemicals outside of the air pump it is wedged between the tank and my open drawer that holds all of my bath and body works scents.. so yes lots of chemicals near it..I didn't even consider that

[Potluck]

Originally Posted by Ellithain

No I do not use anything for cleaning the inside I've used windex on the outside. As for the chemicals outside of the air pump it is wedged between the tank and my open drawer that holds all of my bath and body works scents.. so yes lots of chemicals near it..I didn't even consider that

Don't use windex on the outside of the glass bad idea but that would show ammonia I do believe but I would stop doing that I just wipe mine down with water and a clean soft rag.

[Ellithain]

Even on the outside it can up the ammonia on the inside? its water tight so I don't see how..

[Potluck]

Originally Posted by Ellithain

Even on the outside it can up the ammonia on the inside? its water tight so I don't see how..

Yes you never want to use any chemicals to clean the outside of the tank, they do make special glass cleaner for them though but im sure there are natural cleaners.


1. Use warm water to wet a soft cloth or paper towels.
2. Newspaper works wonderful to clean the glass.
You should not use spray cleaner, such as Windex,
anywhere near the tanks, as the airborne spray can get
in the water.
4. For hard water crystals, soak with a cloth using warm
water to dissolve.

[Ellithain]

Originally Posted by Potluck

Yes you never want to use any chemicals to clean the outside of the tank, they do make special glass cleaner for them though but im sure there are natural cleaners.


1. Use warm water to wet a soft cloth or paper towels.
2. Newspaper works wonderful to clean the glass.
You should not use spray cleaner, such as Windex,
anywhere near the tanks, as the airborne spray can get
in the water.
4. For hard water crystals, soak with a cloth using warm
water to dissolve.

Good to know! Ty