Fish-less cycle - Almost done, but my nitrates wont go down no matter what?

hrrenee

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Ok, so me and everyone on reddit r/plantedtank is confused as all get-out. I am nearing the end of my fish-less cycle; ammonia disappears in 12 hours or less. However, for some unknown reason, my nitrites (5ppm) and my nitrates (40-80) won't go down.

I've done EVERYTHING. Water changes galore. Made sure I was doing everything right. tested my water before putting it into tank. Checked filter. Nothing. It literally does not make sense as to why my nitrates or nitrites (mostly about nitrates) won't go down.

I did a HUGE 75% water change, and cleaned off the diatoms on my tank walls (I read they form when nitrates are too high) and my nitrates went down to 10-20ppm for about 10 minutes, before I took 2 more tests with the API test kit and the last one was telling me in the span of 15 minutes, my nitrates went back up to 40-80ppms.

My pH is 7.2-7.5. Ammonia is 0. Nitrites at 5ppm. Nitrates at 40-80ppm.

At this point I am at a loss, and so is everyone else. I've stopped dosing ammonia per everyone else. Has this happened to anyone before? Is there anything I can do?
 
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hrrenee

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SM1199 said:
You said you tested your tap water. What were the readings?
Readings were; Ammonia; 0, Nitrites; 0 Nitrates; 0 pH; 7.2
 

johnbirg

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Hi,
The bacteria that convert nitrite to nitrate take quite a bit longer to establish than the ammonia converting bacteria. So at this stage your ammonia converting bacteria are keeping up with the ammonia but you still don't have sufficient nitrite converting bacteria yet. If there is no source of ammonia other than what you have been dosing you need to keep dosing it because if you don't you will starve the ammonia converting bacteria and will have to start cycling all over again. The last thing you need to worry about while the tank is cycling is the nitrate level - worry about it when you have zero ammonia and nitrite.
 

MrCarpy

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You say fishless cycle, how long have you done this for? I always cycle my new tank with 2 fish after a couple of days. You need fish too cycle a tank.

What else is in the tank?
 

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MrCarpy said:
You say fishless cycle, how long have you done this for? I always cycle my new tank with 2 fish after a couple of days. You need fish too cycle a tank.

What else is in the tank?
You definitely do NOT need fish to cycle a tank.
 

bizaliz3

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MrCarpy said:
You say fishless cycle, how long have you done this for? I always cycle my new tank with 2 fish after a couple of days. You need fish too cycle a tank.

What else is in the tank?
You can't cycle a tank without an ammonia source.

The ammonia source absolutely does NOT need to be fish.

This is where a fishless cycle comes into play. Google it.
 

mattgirl

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Since this is a fishless cycle you don't need to be overly concerned about the nitrates at this point. Continue adding ammonia at least every other day and just let the cycle do its thing. One day you are going to check the nitrites and seemingly like magic they will be zero.

No need to worry about nitrites and nitrates unless all of a sudden the ammonia stops going down within 24 hours. If that happens then it will be time for a water change.
 
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hrrenee

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mattgirl said:
Since this is a fishless cycle you don't need to be overly concerned about the nitrates at this point. Continue adding ammonia at least every other day and just let the cycle do its thing. One day you are going to check the nitrites and seemingly like magic they will be zero.

No need to worry about nitrites and nitrates unless all of a sudden the ammonia stops going down within 24 hours. If that happens then it will be time for a water change.
Ah so even though my nitrates are through 160ppm right now, I don't need to be worried? And my nitrites are above 5ppm, should I still dose everyday / every other day?
 

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hrrenee said:
Ah so even though my nitrates are through 160ppm right now, I don't need to be worried? And my nitrites are above 5ppm, should I still dose everyday / every other day?
Your original post said your nitrates were at 40/80. Are they now at 160? How long has it been since you did the big water change? How much ammonia are you adding each time? The more ammonia you add the higher both nitrites and nitrates will be.

You could get both down with a water change but as long as your ammonia is still going down your cycle is still moving forward. Occasionally when one has off the chart nitrites and nitrates the ammonia will stop going down or at least slow down.
 

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Dart said:
You definitely do NOT need fish to cycle a tank.
I agree, I am aware. I didn't word that correctly.
 
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hrrenee

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mattgirl said:
Your original post said your nitrates were at 40/80. Are they now at 160? How long has it been since you did the big water change? How much ammonia are you adding each time? The more ammonia you add the higher both nitrites and nitrates will be.

You could get both down with a water change but as long as your ammonia is still going down your cycle is still moving forward. Occasionally when one has off the chart nitrites and nitrates the ammonia will stop going down or at least slow down.
That’s the problem. I’ve done water changes galore. It still won’t come down. I’ve done atleast 2 50% water changes in a day, and 25% water changes every other hour. Nothing works. That’s why I’m trying to figure out why they are so high. And I’m adding 1/2 the dose of the original amount added. 40 drops for a 20 gallon tank, using Dr. Tims ammonia which is 4 drops per 1 gallon.
 

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hrrenee said:
That’s the problem. I’ve done water changes galore. It still won’t come down. I’ve done atleast 2 50% water changes in a day, and 25% water changes every other hour. Nothing works. That’s why I’m trying to figure out why they are so high. And I’m adding 1/2 the dose of the original amount added. 40 drops for a 20 gallon tank, using Dr. Tims ammonia which is 4 drops per 1 gallon.
What test kit are you using?
 

mattgirl

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hrrenee said:
That’s the problem. I’ve done water changes galore. It still won’t come down. I’ve done atleast 2 50% water changes in a day, and 25% water changes every other hour. Nothing works. That’s why I’m trying to figure out why they are so high. And I’m adding 1/2 the dose of the original amount added. 40 drops for a 20 gallon tank, using Dr. Tims ammonia which is 4 drops per 1 gallon.
This is an unusual one but then you already knew that :D Can you describe what you have in this tank. Occasionally I have seen some kinds of decor causing what you are describing even though the decor was supposed to be tank safe. .

The hardest one to figure out was a young lady struggling with off the chart nitrite. No matter how many water changes she did up to and including 100% daily they still shot right back up. I had her remove her decor and the nitrites disappeared. Her tank was cycled but something about that decor was leaching into the water. This decor was bought at her local fish store and was designed for a fish tank but apparently it was causing the problem.
 
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hrrenee

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Rev said:
What test kit are you using?
The apI master test kit, with the cool test tubes and bottles of stuff

mattgirl said:
This is an unusual one but then you already knew that :D Can you describe what you have in this tank. Occasionally I have seen some kinds of decor causing what you are describing even though the decor was supposed to be tank safe. .

The hardest one to figure out was a young lady struggling with off the chart nitrite. No matter how many water changes she did up to and including 100% daily they still shot right back up. I had her remove her decor and the nitrites disappeared. Her tank was cycled but something about that decor was leaching into the water. This decor was bought at her local fish store and was designed for a fish tank but apparently it was causing the problem.
I don’t have any tank decor, but I do have two pieces of wood I got off of buceplant. But they’ve been in there since the beginning of the cycle, so almost two weeks. I have various plants (salivinia floating plants, java ferns, amazon swords, Vallisneria) which are semI doing okay but are starting to get covered with diatoms due to the high nitrates. This is a really weird situation! I just want to fix this as soon as possible.

The only different thing that has happened to my tank in the last few days is me adding Thrive S, but my nitrates were semI high before I started adding this. But could that be the problem?
 

mattgirl

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hrrenee said:
The apI master test kit, with the cool test tubes and bottles of stuff


I don’t have any tank decor, but I do have two pieces of wood I got off of buceplant. But they’ve been in there since the beginning of the cycle, so almost two weeks. I have various plants (salivinia floating plants, java ferns, amazon swords, Vallisneria) which are semI doing okay but are starting to get covered with diatoms due to the high nitrates. This is a really weird situation! I just want to fix this as soon as possible.

The only different thing that has happened to my tank in the last few days is me adding Thrive S, but my nitrates were semI high before I started adding this. But could that be the problem?
That may be your answer as to why your nitrates are so high. The thrive will raise your nitrates. I was shocked when I first started using it.

I should have asked more questions. If you just started this cycle 2 weeks ago then what you are seeing is normal for a cycling tank. As long as your ammonia is still going down within 24 hours of adding it your cycle is still moving forward. At this point I would only add ammonia every other day even if it goes back to zero every day. By doing so you should slow down the production of nitrites and give the nitrite eating bacteria a chance to catch up with the ammonia eating bacteria.

Since this is a fishless cycle water changes at this point in the cycle don't need to be done. Thrive does recommend changing out either 30 or 50% of the water each week so you may need to do that but other than that just let the cycle grow.
 
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hrrenee

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Ah okay. So it's been a few hours, and I've done the following;
- a small 25% WC
- I've taken a couple paper towels and removed the weird oily film that was on top of my water
- I've trimmed decaying leafs off, and removed any plants that have died

.....and guess what! Nitrate readings are down to 10-20ppm. Hopefully I can keep them that way. I am going to hold back the Thrive S dosing, and instead, just got some thrive root tabs in the mail that ill be using for the time being. Hopefully things start kicking off now?
 
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hrrenee

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....aaaaand never mind. Just checked it again; nitrates are back to 80-160ppm. I’m about ready to set this thing on fire.
 
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hrrenee

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Oh my god I’m actually going to die. I’ve been mixing the drops wrong. I didn’t know you were supposed to invert the test tube a few times after the first set of drops. Apparently that makes all the difference when it comes to colors.
oh boy.
 

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hrrenee said:
Oh my god I’m actually going to die. I’ve been mixing the drops wrong. I didn’t know you were supposed to invert the test tube a few times after the first set of drops. Apparently that makes all the difference when it comes to colors.
oh boy.
Glad you figured it out!
 

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