Ammonia, nitrite, and nitrate levels before adding first fish.

[Quandale applesauce]

I started to cycle my 150 gallon tank maybe a month or so ago. It seems to be doing well with ammonia going down from 2 to 0 in less than 48 hours(it may be less than 24 hours now I just haven’t added more ammonia in a while). So I’m just wondering when it’s okay to add my first fish? Ammonia is zero, nitrite is around two, and nitrate is around 30-40. I’m scared to add more ammonia because I don’t want my nitrite to go up even more. I know nitrite is not toxic to salt water fish but at a certain point does it become harmful?

 

[commod0re]

your cycle isn’t complete yet, you still have nitrite

 

[commod0re]

3ppm nitrate is enough to harm marine fish over time. iirc anything above 0.2 ppm is enough to cause stress in at least some things. I’d just give it more time

 

[BeanAnimal]

3ppm nitrate is enough to harm marine fish. iirc anything above 0.2 ppm is enough to cause stress in at least some things

Neither nitrite or nitrate is harmful to marine fish at any reasonable level attainable in reef aquarium. Fresh water is a different story. I would't waste salt on a water change either, there really is no benefit at this point.

If the aquarium is processing ammonia (it is) then it is ready for fish.

There is also no need to add any more ammonia. It only really needs to happen once, twice if you insist on proving to yourself it dropped the first time.

 

[allof fish]

Neither nitrite or nitrate is harmful to marine fish at any reasonable level attainable in reef aquarium. Fresh water is a different story. I would't waste salt on a water change either, there really is no benefit at this point.

If the aquarium is processing ammonia (it is) then it is ready for fish.

I agree. I would be concerned about how much nitrates you have. How much ammonia did you add. But no you should be all good. Waiting any longer won’t hurt if you wanted to add things like phyto, pods and cleanup crew but i usually do that at once when fish and coral start going in

 

[exnisstech]

Hmm. I don't test ammonia or nitrite. When I see nitrate I figure ammonia is being processed or there wouldn't be nitrate. I know nitrite can effect nitrate test results but I've cycled maybe 10 tanks to date and don't own an ammonia or nitrite test kit. I just roll this way and not a recommendation.

 

[commod0re]

Neither nitrite or nitrate is harmful to marine fish at any reasonable level attainable in reef aquarium. Fresh water is a different story. I would't waste salt on a water change either, there really is no benefit at this point.

If the aquarium is processing ammonia (it is) then it is ready for fish.

https://www.globalseafood.org/advoc...cies-susceptibility-environmental-conditions/

> There is a large body of information on nitrite’s toxicity to fish, shrimp and other aquatic organisms. The 96-hour LC50s for nitrite-nitrogen typically range 10.00-30.00 mg/L for freshwater invertebrates and 0.25-100.00 mg/L for fish. The respective ranges for marine organisms are typically 10-300 mg/L and 100-1,000 mg/L. The 96-hour LC50s for several species of aquatic animals are presented in Table 1.

According to the attached table, it can take as little as 10ppm nitrite to be lethal within 96 hours depending on species. This only covers death and not lesser levels of harm/stress, both of which can be achieved at much lower levels than are considered lethal.

While we may be able to confidently say that 3ppm of nitrite is unlikely to kill marine fish or other invertebrates, there is actually no basis to say that it cannot possibly harm or stress them at all. The presence of nitrite also confounds the results of most nitrate tests, giving falsely high readings. Personally I would choose to wait a bit longer given that. OP says they started the tank a month ago so it’s likely only to need another couple of weeks at most anyway

 

[Fish Fan]

I started to cycle my 150 gallon tank maybe a month or so ago. It seems to be doing well with ammonia going down from 2 to 0 in less than 48 hours(it may be less than 24 hours now I just haven’t added more ammonia in a while). So I’m just wondering when it’s okay to add my first fish? Ammonia is zero, nitrite is around two, and nitrate is around 30-40. I’m scared to add more ammonia because I don’t want my nitrite to go up even more. I know nitrite is not toxic to salt water fish but at a certain point does it become harmful?

You're cycled, and safe to start to slowly add some hardly livestock, especially in 150 gallon volume

As Bean mentioned, nitrite is totally non-toxic in levels achieved in home aquaria. Here's more info on that:
http://reefkeeping.com/issues/2005-06/rhf/index.htm

You also cannot know your real nitrate concentration right now because nitrite (though non-toxic) causes a false high result for nitrate testing. Therefore, you can't really say that your nitrate is high until all the nitrate has gone to zero. For that reason, I wouldn't worry about a water change at this time

Here's a post from RHF on nitrite interfering with nitrate testing:
https://www.reef2reef.com/threads/s...k-what-do-you-recommend.1162025/post-14415904

I hope this helps!

 

[Fish Fan]

https://www.globalseafood.org/advoc...cies-susceptibility-environmental-conditions/

> There is a large body of information on nitrite’s toxicity to fish, shrimp and other aquatic organisms. The 96-hour LC50s for nitrite-nitrogen typically range 10.00-30.00 mg/L for freshwater invertebrates and 0.25-100.00 mg/L for fish. The respective ranges for marine organisms are typically 10-300 mg/L and 100-1,000 mg/L. The 96-hour LC50s for several species of aquatic animals are presented in Table 1.

According to the attached table, it can take as little as 10ppm nitrate to be lethal within 96 hours depending on species. This only covers death and not lesser levels of harm/stress, both of which can be achieved at much lower levels than are considered lethal.

While we may be able to confidently say that 3ppm of nitrate is unlikely to kill marine fish or other invertebrates, there is actually no basis to say that it cannot possibly harm or stress them at all. The presence of nitrite also confounds the results of most nitrate tests, giving falsely high readings. Personally I would choose to wait a bit longer given that. OP says they started the tank a month ago so it’s likely only to need another couple of weeks at most anyway

Please see the link I posted just above about nitrite toxicity in aquaria, it should help

 

[commod0re]

Please see the link I posted just above about nitrite toxicity in aquaria, it should help

Likewise. Your link doesn’t even open for me

 

[Fish Fan]

Likewise. Your link doesn’t even open for me

Give it a few and try again, it works

It's an article from Randy Holmes-Farley on nitrite toxicity in aquaria specifically, and how it's nothing to worry about. He has his own LC50 numbers as well. The article you linked appears to be from a seafood aquaculture facility, and myself and many others here on R2R defer to Randy for things like this

 

[Randy Holmes-Farley Verified Community Expert]

I agree you are ready for fish.

The nitrite is zero concern. It takes massive amounts of nitrite in seawater to kill fish or anything else we keep.

The nitrate is a false reading caused by the nitrite.

Good to go!

 

[commod0re]

Give it a few and try again, it works

It's an article from Randy Holmes-Farley on nitrite toxicity in aquaria specifically, and how it's nothing to worry about. He has his own LC50 numbers as well. The article you linked appears to be from an seafood aquaculture facility, and myself and many others here on R2R defer to Randy for things like this

I’m not disagreeing with what you or he say per se, but death isn’t the only consequence that could be considered “harm” and so to say that no harm can possibly be caused and then only back that up with lethality statistics and nothing else is imprecise at best and that’s the part I challenge. It would only add a little more time to wait for the nitrite processors to finish catching up so it’s weird to me that would be controversial

 

[Fish Fan]

I’m not disagreeing with what you or he say per se, but death isn’t the only consequence that could be considered “harm” and so to say that no harm can possibly be caused and then only back that up with lethality statistics and nothing else is imprecise at best and that’s the part I challenge. It would only add a little more time to wait for the nitrite processors to finish catching up so it’s weird to me that would be controversial

I have no problem if you or anyone wants to take the patient way and wait for the nitrite to resolve, it can't see how that hurts, and then you'd know where you stand with the nitrate more clearly

 

[commod0re]

I have no problem if you or anyone wants to take the patient way and wait for the nitrite to resolve, it can't see how that hurts, and then you'd know where you stand with the nitrate more clearly

Likewise I wouldn’t get upset about someone not waiting for it for the reasons you, BeanAnimal, and Randy gave either, I just think the potential for lesser consequences like stress should at least be mentioned too so it can be taken into account when OP decides how they want to proceed :)

 

[Randy Holmes-Farley Verified Community Expert]

I’m not disagreeing with what you or he say per se, but death isn’t the only consequence that could be considered “harm” and so to say that no harm can possibly be caused and then only back that up with lethality statistics and nothing else is imprecise at best and that’s the part I challenge. It would only add a little more time to wait for the nitrite processors to finish catching up so it’s weird to me that would be controversial

Requiring it is fine, but unnecessary.

I'd certainly revise that opinion oif there is evidence of tox at any nitrite level actually reached in reef aquaria for organisms we keep, but I have not seen any such data.

When actual LC50 tox for a fish is HUNDREDS of ppm (like nitrate), telling someone with 2 ppm to wait to add a fish seems overkill to a large degree.

 

[Quandale applesauce]

I started to cycle my 150 gallon tank maybe a month or so ago. It seems to be doing well with ammonia going down from 2 to 0 in less than 48 hours(it may be less than 24 hours now I just haven’t added more ammonia in a while). So I’m just wondering when it’s okay to add my first fish? Ammonia is zero, nitrite is around two, and nitrate is around 30-40. I’m scared to add more ammonia because I don’t want my nitrite to go up even more. I know nitrite is not toxic to salt water fish but at a certain point does it become harmful?

You're cycled, and safe to start to slowly add some hardly livestock, especially in 150 gallon volume

As Bean mentioned, nitrite is totally non-toxic in levels achieved in home aquaria. Here's more info on that:
http://reefkeeping.com/issues/2005-06/rhf/index.htm

You also cannot know your real nitrate concentration right now because nitrite (though non-toxic) causes a false high result for nitrate testing. Therefore, you can't really say that your nitrate is high until all the nitrate has gone to zero. For that reason, I wouldn't worry about a water change at this time

Here's a post from RHF on nitrite interfering with nitrate testing:
https://www.reef2reef.com/threads/s...k-what-do-you-recommend.1162025/post-14415904

I hope this helps!

So even before I add fish I shouldn’t do a water change? Would it be reasonable to do one just to be precautious?

 

[Randy Holmes-Farley Verified Community Expert]

https://www.globalseafood.org/advoc...cies-susceptibility-environmental-conditions/

> There is a large body of information on nitrite’s toxicity to fish, shrimp and other aquatic organisms. The 96-hour LC50s for nitrite-nitrogen typically range 10.00-30.00 mg/L for freshwater invertebrates and 0.25-100.00 mg/L for fish. The respective ranges for marine organisms are typically 10-300 mg/L and 100-1,000 mg/L. The 96-hour LC50s for several species of aquatic animals are presented in Table 1.

According to the attached table, it can take as little as 10ppm nitrite to be lethal within 96 hours depending on species. This only covers death and not lesser levels of harm/stress, both of which can be achieved at much lower levels than are considered lethal.

While we may be able to confidently say that 3ppm of nitrite is unlikely to kill marine fish or other invertebrates, there is actually no basis to say that it cannot possibly harm or stress them at all. The presence of nitrite also confounds the results of most nitrate tests, giving falsely high readings. Personally I would choose to wait a bit longer given that. OP says they started the tank a month ago so it’s likely only to need another couple of weeks at most anyway

To clarify, that is nitrite-N. Not ppm nitrite.

I also think there is something possible misleading about the table.

It only lists a few marine species, and only a couple are as susceptible as you suggest, but weirdly, one that does show tox as low as 30 ppm nitrite shows a massive range (white shrimp 9.0-322.0 mg/L nitrite-N).

But then it says

Some of the variation in toxicity relates to the species’ differences in nitrite susceptibility. For example, the 96-hour LC50 in Pacific white shrimp at 35-ppt salinity is 322.0 mg/L, while at the same salinity, the value for black tiger prawn is only 14.0 mg/L. At a chloride concentration of 22.0 mg/L, the 96-hour LC50 for channel catfish is 7.5 mg/L, while for fathead minnows, it is 70.0 mg/L.

Which leads me to believe that the low values of LC50 for the white shrimp are not actually at 35 ppt, but at a lower salinity.

 

[Randy Holmes-Farley Verified Community Expert]

So even before I add fish I shouldn’t do a water change? Would it be reasonable to do one just to be precautious?

Nothing wrong with it, but its a waste of time and money. It's a carry over, IMO, from two things:

1. Folks beleived that nitrate was high (yours is not).
2. Folks wanted nitrate very low (which is, IMO, a old and defunct idea).

 

[commod0re]

Requiring it is fine, but unnecessary.

I'd certainly revise that opinion oif there is evidence of tox at any nitrite level actually reached in reef aquaria for organisms we keep, but I have not seen any such data.

When actual LC50 tox for a fish is HUNDREDS of ppm (like nitrate), telling someone with 2 ppm to wait to add a fish seems overkill to a large degree.

I’m not asking you to revise your opinion but I think we can at least agree that death is not the only possible outcome that could be considered harm and that implication is what I’m challenging today. If an aquarist is aware that it presents a slight risk and chooses to take that risk I wouldn’t balk at it. What I find odd is bringing it up as a possibility and then being told repeatedly that that is impossible, but the only thing any of you can back it up with are the same lethality statistics that I already also mentioned lol