Nitrite toxicity discussion

[threnjen]

The effect of pH variation, within the range 6.5, 7.0, 7.5, 8.5 and 9, on activated sludge denitrification of a synthetic wastewater

.......

(Cited from various references)

.....I'm along for the ride!

This was all about ammonia toxicity unless I misunderstand something. I'm not really sure what you and Caliban both are talking about I guess regarding this article. We're talking about preventing nitrite toxicity.
Salt doesn't raise your pH (NaCl) I don't think, does it? Should I check?

Edit: I now understand your point and purpose but believe I have addressed it, see my replies a few down.

 

[Caliban07]

This was all about ammonia toxicity unless I misunderstand something. I'm not really sure what you and Caliban both are talking about I guess regarding this article. We're talking about preventing nitrite toxicity.
Salt doesn't raise your pH (NaCl) I don't think, does it? Should I check?

Re-reading I'm not sure myself.

 

[threnjen]

Here is a link explaining nitrite toxicity in saltwater... or the lack of it . Surprisingly nitrite is not toxic in saltwater like many believe it to be.

Nitrite and the Reef Aquarium by Randy Holmes-Farley - Reefkeeping.com

Thanks,this was really interesting. and just more confirmation of the protective value of chlorides.

 

[threnjen]

Re-reading I'm not sure myself.

I think there is confusion about the source of the Chloride.

J Mcpeak mentions calcium chloride which increases the hardness and calcium content of the water, and probably raises pH. After all we know that adding crushed coral, Equilibrium, etc raises the pH as it increases the gH/kH.
Running from that, he pointed out that a high pH increases NH3 levels which can be harmful for the fish in the cycle.

I'm proposing sodium chloride (table salt) which I don't believe raises pH and therefore is not making ammonia levels more dangerous. However I can't be certain it doesn't raise pH so I suppose I should check.

Aquarium salt is sodium chloride just like table salt; so is Kosher salt. Calcium chloride is something entirely different, so its effects on pH are not really relevant to the discussion. Epsom salts are magnesium sulfate and not "salt" the way we think of it. Aquarium salts are not magnesium or calcium based.

I hope this helped clear things up, JMcpeak

 

[threnjen]

Haaaa I have something funny -
I missed last night on my TDS meter that it was flashing
"x 10"!!!! when I got the 200ish TDS reading (it only shows 3 digits and apparently that's how it makes it higher to read up to 9999)
So that salt last night actually made the water 2000 TDS.
Meaning the rate would be 1/2tsp per 10 gallons per 1ppm nitrite. It's quite low.



So - just now. I filled a 1 gallon jug with warm water. 17 TDS. I added 1 tablespoon of sodium chloride NaCl. TDS now 5500.
Initial pH around 7.2, new pH around 7.4
So it did go up a little - but this was the amount of salt to use in 60 GALLONS of water, and I put it in 1 gallon.

In conclusion: sodium chloride pH raising is negligible, making it the best protective chloride to promote nitrite protection.
Also, for general use, I am NOT a proponent of salt. But it takes 3tbsp for an entire 60 gallons (per 1ppm nitrite). This is really a pretty darn low amount of salt. I see people put in a LOT more as a "preventative" measure (although they are using aquarium salt which is larger chunks)

I also ran a check that I was reading the TDS meter properly. I added more salt to the jug until I read 946 x10, then I added more salt and it would no longer give a reading. This TDS meter goes up to 9999 so that was what I expected.

 

[threnjen]

Just as a note the 1/2 tsp/10 gallons was using table salt, which is very fine grained. I would need to find the proper calculation using aquarium and/or kosher salt since it is chunky. As I understand it we should not use even non-iodized table salt because of the anti-caking agent (what is it? its its danger a myth?)

 

[threnjen]

Aha. The anti-caking agent in the table salt that I was using for my test is calcium silicate. That is the source of the pH rise.
Sodium chloride with no additives (aka Aquarium) should not raise the pH at all.

Edit: for the record, calcium silicate is a mixture of limestone and diatomaceous earth, neither of which are dangerous. So if people happen to have Morton brand non-iodized salt, this is a perfectly safe brand of table salt.

Edit again: Supposedly, even the whole non-iodized thing is a myth. Read this claim:
"freshwater aquarium salt- This is dehydrated sea water. Sea salt is not regulated and has more elements in it then tablesalt. Actually in most cases iodine and iodides are greater in sea salt then iodized tablesalt. Other elements are copper ( can be harmful to inverts and plants) and calcium carbonate (will raise pH and KH). Even though these things are present in sea salt they are also trace elements of freshwater. Matter of factly iodine is a freshwater trace element for freshwater fish. They need it for the same reasons humans do, preventing growths. The amount reccomended is actually more then is put in tablesalt when diluted in aquarium water."
The claim was not substantiated with evidence, but bears more research.
http://forums.gardenweb.com/forums/load/aquarium/msg062244164624.html?7

Sodium Silicoaluminate is another possible caking agent, this is a form of zeolite (the stuff ammo chips are made of)

The bad caking agent is Yellow Prussiate of Soda which is a form of cyanide. Even this is debated as the amount is sooooo small.

Edit: apparently Kosher salt has an anti-caking agent as well.

However my conclusion is that any salt with a sodium or calcium caking agent is safe.

 

[threnjen]

Salt would not play well with ammo chips. Zeolite is recharged through a salt solution.
Edit: the level of salinity in 100ppm would not be enough to make it release ammonia, so disregard this.

 

[Caliban07]

Good work threnjen. So tell me, just how much m/g did that half teaspoon if salt weigh?

 

[threnjen]

just found my super accurate scale. Few minutes and I will tell you the 100ppm weight and spoon amount for Kosher, table and aquarium salt.

 

[Caliban07]

just found my super accurate scale. Few minutes and I will tell you the 100ppm weight and spoon amount for Kosher, table and aquarium salt.

I would like to know how many mg/l for 1ppm nitrite if you could

 

[threnjen]

Table salt:
3.55g or 1/2 level tsp added 1142ppm to 1 gallon water.
So appx 1/2tsp (3550mg) per 10 gallons of aquarium water, which is appx 1/2 tsp per 40 liters (37.85 liters). So weight per 10L using more accurate conversion is 938mg. That would be really small on a spoon though. I think the smallest you could present it as a measurement is 1/4tsp per 20L.
This yields appx 100ppm, protection for 1ppm nitrite. (will actually yield about 114ppm, so maybe just stress that the spoon should not be mounded but level or even a bit under)


Kosher salt:
2.56g or 1/2 level tsp added 790ppm (not enough, goal 1000)
Added .94 g made it 1040ppm, so perfect.
So still about 3500mg of salt per 10 gallons, or 40 liters. 925mg per 10 liters.
Kosher is chunkier though, so this would be most accurately described as 1/2 MOUNDED tsp if not going by weight.
note: My Kosher salt has Yellow Prussiate as the anti-caking, and it's the same brand as my table salt. This means that my table salt with calcium silicate is actually SAFER than the Kosher salt, even though I see people recommend using Kosher salt as an Aquarium salt alternative.

Working on the aquarium salt now. It takes longer to dissolve.

 

[threnjen]

Aquarium salt:
3.28g or 1/2 level tsp added 940ppm. Pretty close then.
I bet the "magic" spot is still 3.5g. It seems that the weight is all that really matters.
So same conversions as the other two, for weight

I would say about 930mg of any kind of salt per 10l would yield the accurate results.

 

[threnjen]

Edited first salt post with some liter conversions
Edit: and added post for aquarium salt. all done!

 

[Caliban07]

I missed something along the way. Why are you aiming for 100 ppm salt again for 1 nitrite?

 

[threnjen]

I missed something along the way. Why are you aiming for 100 ppm salt again for 1 nitrite?

That was just the recommended amount in one of the papers I read by some fisheries expert. It was this one:
http://www.aces.edu/dept/fisheries/aquaculture/documents/BrownBlood.pdf

What was the recommended amount in that first paper you posted? I can't remember.

I need to do that crazy thing where I take notes while I read through all of them so we can come up with a more blanket recommendation. Otherwise I forget quickly what I read and where.

 

[Caliban07]

Aquarium salt:
3.28g or 1/2 level tsp added 940ppm. Pretty close then.
I bet the "magic" spot is still 3.5g. It seems that the weight is all that really matters.
So same conversions as the other two, for weight

I would say about 930mg of any kind of salt per 10l would yield the accurate results.

So that would be 93mg/l of salt to protect against 1ppm nitrite. 46.5mg/l to protect against 0.5ppm and 23.25mg/l to protect against 0.2ppm nitrite.

 

[Caliban07]

That was just the recommended amount in one of the papers I read by some fisheries expert. It was this one:
http://www.aces.edu/dept/fisheries/aquaculture/documents/BrownBlood.pdf

What was the recommended amount in that first paper you posted? I can't remember.

I need to do that crazy thing where I take notes while I read through all of them so we can come up with a more blanket recommendation. Otherwise I forget quickly what I read and where.

It actually just says 2mg/l offsets 0.76mg/l of nitrite

 

[threnjen]

Sounds good. But, most people don't have a scale that accurate, so we have to be able to disseminate in a more understandable form.

Do guys use stuff like tsp and Tbsp?? I don't actually know.
(why oh why doesn't the US convert to metric and stop being so dumb and annoying)

 

[threnjen]

It actually just says 2mg/l offsets 0.76mg/l of nitrite

Wow so that paper is really different. 2mg/l for .76ppm nitrite, and the paper I referenced was 93mg/l for 1ppm nitrite??

OK but... maybe in GOOD news... the amount of salt we are talking about is overall really, REALLY low. I mean 1/2tsp per 40l is really nothing. So even if we estimate high, there's really little chance of any sort of "damage" to the fish that are less salt tolerant. (in my opinion)