Nitrites won't go down

[Molly Malone]

Hi all,

New to any fish/aquarium forum, in terms of posting a question. So, thought I'd give it a try to get some help with lowering my nitrites.

Couldn't stand not having a pet of any kind anymore and dug up my old aquarium out of the basement to clean it out and see what equipment still worked. In the mean time, set up a glass terrarium "bowl" and had lots of issues/didn't realize small tanks were harder to cycle (~5 gal), etc. seemed to have forgotten everything I knew about fish keeping and aquaria, etc.

Subtropical/temperate freshwater set up (moderately planted): 2 Bloodfin Tetras and 2 White Cloud Mountain Minnows, which would have been tight as it is, but the local PetSmart gal recommended I get 2 Albino Cory Cats as well, which put it over the top. I lost a White Cloud due to my own harassment in attempting to keep the 5 gal clean while setting up the other one. I was just doing too much, forgetting what I'd known, and listening to the wrong person at PetSmart (there are a couple who know what they're doing, but not all).

So, I hurriedly cleaned up and set up the regular 10 gal and my fish expert at the preeminent (I'm not being sarcastic, they really are extremely knowledgeable) area aquarium store, suggested I go ahead and get them out of the small tank and into the 10 I'd had running now for a few days and just cycle that tank w/those fish. (mid-April set up)

So, they are all doing well and seem happy. However, my cycle seems to have stalled with high nitrites that I can't seem to get down even with massive water changes.

API test results: (tap water is pH 7.6, 0 NH3, 0 N2, and 0 N3)

pH 6.5 (I had a Terracotta pot--yes I know that should be neutral, but that was the only addition--that lowered the pH significantly, from 7.3 to 6.3-- and have used neutralizer a few times, but w/all the massive water changes, you'd think I wouldn't need it)

Ammonia 0
Nitrites ~5 ppm
Nitrates ~15 ppm

Doing say 20% water changes each day would usually result in a drop from 4 or 5 down to ~1.5 but it would be up the next morning to 4 again. Now the PWCs don't seem to be having any indicator color change, and I'm worried about nitrite poisoning, so for the past 2 days, I've done these massive PWCs of 50% and then an hour later a 2nd 50%. Not much by way of change in the indicator color (seems to be still around 5) thoug!

Now the only difference between the gradual movement I WAS seeing (where the test would go down to ~1.5 after the PWC) and now is:

1) the temperature in the house has gone up and therefore the temp in the tank (remember my tank is subtropical/unheated regularly at 70 degrees),
We've bypassed spring and leapt headlong into summer HOT, turned the AC on in the house hot. So, now the temp in the aquarium is 75 degrees. While this should give better water oxygenation, is this resulting in lengthening the Nitrite portion of the cycle? Is that possible? Or am I reaching, looking for excuses?​

2) I got it in my head to add a capful of quick start both yesterday and today in my lame quasi-attempt to speed up the process. Did I just increase the bioload and the make it even harder for the nitrate bacteria to catch up?​

Thanks for reading my lengthy question. Basically, I'm wondering if there is something that I could be doing differently. Any ways that I can quicken this portion of the process? Or if I could be doing something wrong?

Anxiously awaiting the completion of the cycle! The single White Cloud is happy as can be, as are the corys, so I'm more anxious about adding 3 more Bloodfins as soon as possible so they can school. I noticed that when the Nitrites rose, dorsal fin gets a bit paler in the smaller of the 2, and they've been a bit testy following each other around, but luckily no nipping, more so that one is annoying the other.

Thanks!

 

[Delapool]

Hi, welcome to the forum

Looking at tank water tests the low ph may be slowing down the cycle. Below a ph of say 6.5 the nitrifying bacteria start to reduce activity. So I would keep up the water changes and also add some crushed shells (or anything of carbonates) which will help buffer the water.

Seachem prime or a pinch of table salt will detoxify nitrites / prevent nitrite poisoning in fish.

Unfortunately tank cycling is a long process, I feel your pain.

If you have a kh test would be worth checking how soft your water is.

 

[PB_Smith]

actually the colder temps are most likely what was stalling the cycle. for the BB to fully colonize and reproduce quickly for that 4-6 weeks cycle, the temps need to be ~76-82.
You will probably begin to see it progress with the higher temp.
Your ph is far too low at 6.3, that is also problematic for cycling a tank.
you should strive for 7-7.5 for the fish you are keeping, but no lower that ~6.8


What you are most likely seeing is the increased activity of the bacteria that converts ammonia resulting in faster production of nitrite.


the faded colors should be expected as nitrite interferes with the bloods ability to carry oxygen, so you should also direct any filter output to disturb the water surface as much as possible to aid oxygenation.


higher temps will actually result in less dissolved oxygen in the water, not more, so as the temp increases, so does the need for good surface agitation/oxygenation.


Dosing Seachem Prime at up to 5 times normal has been shown to help with nitrite toxicity, so that's a possibility, as mentioned above.


finally, have you tested your source water for nitrite? you may be re-introducing it in water changes. My tap water has nitrate and copper, so I never use it.


bottom line, the warmer temp is good and will help the process and you need to raise the ph back up to around 7-7.5.

 

[Delapool]

Thanks, that's a good point on temps.

 

[Molly Malone]

Thanks all!

re: "higher temps will actually result in less dissolved oxygen in the water, not more, so as the temp increases, so does the need for good surface agitation/oxygenation."...

This is the site ("How Many Fish?" Aquarium Stock Level Calculator) where I got the idea that colder waters needed more dissolved Oxygen. In the section about oxygen needs, it said, "Cold water tanks and marine tanks have higher surface requirements." That's where I thought that meant the opposite would hold true re warmer water. So, did I misunderstand? (thanks for your help on this)

Re: The nitrites in my local water supply, I tested the tap water and it was 0 across the board (see above).

Re: Water hardness. My water tends to be hard (typically averaging about 120–130 milligrams per liter). Moderately Hard is 60-120 and Hard is 120-180, so my tap water is in between Moderately Hard and Hard.

Re: pH. The pH was low for 12 hrs and is back to normal ~7, so not sure that short duration would cause the cycle to stall? My water is higher pH, 7.6 and I know the Corys prefer a slightly acidic pH, so I try and keep at 7.

Yes, the Bloodfins fade when stressed in general, lack of schooling partners and high nitrites. The one that has faded usually perks up in color after a pwc.

I have a filter that is rated at 200gph. Best advice I ever got from the great LFS that told me to get this filter rated for 30 gal. I know that I'll never get another filter rated for the exact number of gal of the tank.

Just did a 60% wc and nitrites are down to .5....we'll see how long that lasts...

 

[Delapool]

Ph drop in that interval shouldn't cause a stall. One to keep an eye on as sounds like tank is chewing through the buffers as it cycles. Good luck, look forward to pics

 

[Molly Malone]

Thanks, help me out with this (...One to keep an eye on as sounds like tank is chewing through the buffers as it cycles)... can you explain what this means in more detail? Are you talking about the natural buffers/alkalinity of the water (did I get that right?)? How is it going thru buffers quickly?

(Nitrites are moving a little, I guess I'm impatient.)

I thought I added a video but it won't post.

 

[Molly Malone]

Let's try adding a pic of an earlier stage (not a great one). Plants are a mix of fake and real. Transitioning. Fish are sooo funny, they run into resistance when swimming through the fake plants and they "bump" into it not expecting that... they look at it like "what's that???"

 

[Delapool]

Thanks, help me out with this (...One to keep an eye on as sounds like tank is chewing through the buffers as it cycles)... can you explain what this means in more detail? Are you talking about the natural buffers/alkalinity of the water (did I get that right?)? How is it going thru buffers quickly?



(Nitrites are moving a little, I guess I'm impatient.)



I thought I added a video but it won't post.

Here's the formula I have:

1 ppm ammonia -->; 2.7 ppm nitrite -->; 3.6 ppm nitrate.

For every gram of ammonia oxidised into nitrate 4.8 grams of oxygen is used, 7.14 grams of calcium carbonate is used.

If my tank overloads with ammonia (which I tend to do on occasion with root tabs), I find watching the kh (carbonate hardness) will show what the ph is going to do. Once kh starts dropping below say 3, I have found a ph drop is not far off. As you say, the natural (ph) buffers are almost exhausted. A water change or adding carbonates holds kh steady which then stops ph dropping.

 

[Molly Malone]

Woo hoo, I thought I had 2 male Bloodfins, after I started feeding freeze dried bloodworms, it stopped being about "I want to school w/you" to somewhat different behavior... following around like a puppy dog. And I thought, hmmm, maybe that's a girl fish? 3 days later, spawning. Got to see the jump out of the water ritual

 

[Delapool]

Sounds brilliant! Good news going well.