Help With Nitrites Anyone?

[Benunited]

Hi folks

Newbie here. Have had fish in my 30 litre biorb for about a month now following a fishless cycle.

Have 4 small guppies and 4 neon cardinals. Some folk say this is fine for a 30 litre biorb, some folks say it is maybe too much.

Anyhow, for the last 10 days I've been getting very, very small nitrite readings. Probably less than 0.1. Every day I've been doing an approx 40 percent water change, dechlorinating the water first.

As I have soft water which seems to make it prone to ph crashes I'm also adding small amounts of bicarb powder, which seems to keep the ph steady at around 7.

Ammonia readings are always zero. Nitrate reading this morning was a bit below 5.

The fish all seem healthy, other than maybe one cardinal who is a bit listless at times.

The biorb has a sponge filter. Although the company wants me to replace this every 6 weeks, on advice from fishkeepers I've instead only been rinsing the sponge out in old tank water so as to keep the bacteria in the sponge.

Saying that, the biorb comes with ceramic media, which I believe is where almost all of the bacteria required is 'stored'.

The biorb also comes with an oxygen pump which seems to pump through the filter.

Does anyone have any advice what else I should be doing please? I know my nitrite readings should be zero at all times.

I don't think I'm feeding the fish too much as I'm giving them only tiny amounts once a day.

One thing that surprised me was I asked in the shop where I bought the fish and they said not to bother about the nitrite reading! This goes against everything I've been told. They said only to test for nitrates. Reason they gave was nitrates will do more harm to my fish and if there are any nitrites in the tank you can guarantee there will be nitrates. Were they talking sense? I thought nitrite poisoning was higher cause of death than nitrate?

As you can guess, I'm a bit puzzled and rather worried about my fish.

Also, I've bought aquarium salt as I've been told this can help reduce harm. I bought a brand which is also supposed to be a ph buffer.

Anyone with any advice? Much appreciated!

 

[shelaghfishface]

hia.. did you add all the fish at once or in stages?- they suggest adding 1 fish per 28 days ( and the filters take a while to catch up)
what kind and how old is the test kit?
no ..stuff what reef one say ,dont change the sponge till its falling apart ( just rinse in water that you take OUT of the tank)
the best thing you can do is as many water changes as you can.. maybe your test is dodgy
i wouldnt be adding salt either ( well i would if i was treating something,but not otherwise)

let us know
shelagh xx

 

[fatheadminnow]

First off, this is not a fishless cycle. If this was a fishless cycle then you would not have fish in the tank, Hence fishless.

What you are in is a fish-in cycle, and it seems you are at the second stage in the cycle where you are getting nitrite readings.

Just keep on doing what you are doing, keep the nitrite level below .25 ppm by doing water changes. Soon the nitrite spike will pass and it will be reading 0 ppm, at which point your nitrate will start to rise faster. When your ammonia and nitrite have remained at 0 ppm for one week without doing water changes, then you can consider your tank cycled!

-FHM

 

[Benunited]

hia.. did you add all the fish at once or in stages?- they suggest adding 1 fish per 28 days ( and the filters take a while to catch up)
what kind and how old is the test kit?
no ..stuff what reef one say ,dont change the sponge till its falling apart ( just rinse in water that you take OUT of the tank)
the best thing you can do is as many water changes as you can.. maybe your test is dodgy
i wouldnt be adding salt either ( well i would if i was treating something,but not otherwise)

let us know
shelagh xx

Hi Shelagh

Added the 4 cardinals to start with - thought it best not to start with just one given they don't like to be by themselves - maybe a mistake?

The test kit is Nutrafin liquid test kit - about 4 months old, bought when I started the fishless cycle.

Thanks

Ben

First off, this is not a fishless cycle. If this was a fishless cycle then you would not have fish in the tank, Hence fishless.

What you are in is a fish-in cycle, and it seems you are at the second stage in the cycle where you are getting nitrite readings.

Just keep on doing what you are doing, keep the nitrite level below .25 ppm by doing water changes. Soon the nitrite spike will pass and it will be reading 0 ppm, at which point your nitrate will start to rise faster. When your ammonia and nitrite have remained at 0 ppm for one week without doing water changes, then you can consider your tank cycled!

-FHM

Hi FHM
Are you sure this is a fish-in cycle? Reason I ask is I thought I had completed my fishless cycle before adding my first lot of fish.
The fishless cycle – if that’s what it was – took me about 2 months and I had a full week of zero readings for ammonia and nitrite before adding the fish. Was that not the fishless cycle complete?
It’s only in the last ten days I’ve started to get nitrite readings....

 

[fatheadminnow]

Oh then yes, if you added ammonia then yes, that would be a fishless cycle.

It is just weird that you have nitrites now if you properly did a fishless cycle?

-FHM

 

[waterdrop]

My guess is that the 0.10 nitrite(NO2) is showing that the filter is marginal. You are not technically overstocked for 30L/7.9G volume I don't thing, probably right at full stocking but I don't think the filter is quite up to full stocking or Shelagh is right and its perhaps being extra slow working its way up to handling the current bioload.

Just as we hear a lot, the LFS was dead wrong about nitrite(NO2) versus nitrate(NO3.) Nitrate(NO3) can build up between water changes and not be harmful to most species. In fact some species have been found to do ok in 400ppm and some catfish even in 1000ppm. That said though, the goal should be to try and keep it below 20ppm above whatever your tap water level is.

Nitrite(NO2) is a completely different story. The two oxygens of the nitrite ion can lock in to the same positions on the fish blood hemoglobin protein as normal oxygen (O2) does. But the NO2 will then commence to destroy the hemoglobin and the red blood cell, turning it into a brown mush. This basically amounts to quick suffocation and leads almost immediately to brain damage and permanent nerve damage. The result is a shortened life or it can cause death. This harm varies by species but the general danger line we use when not referring to species is 0.25ppm of nitrite(NO2) (as measured by a liquid-reagent based test,) this often being the first color match-up of the test kit.

I don't think the trace of nitrite you are seeing is going to be overly harmful but we really don't like to see even traces in a well-running bio-filter system, so it would be good to get it sorted out.

~~waterdrop~~