Study: Nitrates and other parameters in Amazon waters

[jcardona1]

Not sure if folks here would find any interest in this, but I found this study on another forum. Pretty interesting so I thought I'd share! It took place in the 80s / early 90s and they covered several rivers along the Amazon basin. What really caught my attention is the ph and nitrate readings.

The study: ftp://daac.ornl.gov/data/lba/surf_hydro_and_water_chem/CAMREX/comp/Pre_LBA_CAMREX.pdf
The data: ftp://daac.ornl.gov/data/bluangel_harvest/camrex/data/chemistry/chemdata.txt



In the tables, you'll see that the Rio Negro has ph readings in the 4s!!!!

With nitrates, the highest reading I saw was for Rio Jurua at 22.8uM. I converted that as follows:

Nitrate (NO3) has a molecular mass of 62.0049 g/mol. So:

62mg/mmole = 62ug/umol
22.8uM = 22.8umol/L, so 22.8umol/L x 62ug/umol = 1414ug/L = 1.414mg/L.
Rounded off, this would be about 1.4mg/L, or 1.4ppm of nitrates (I think I did that right!)

That basically supports that nitrates are nonexistent in the wild. I still don't get how some guys justify having 40-80ppm in their tanks and saying it's ok

​

 

[ceeej31]

Not sure if folks here would find any interest in this, but I found this study on another forum. Pretty interesting so I thought I'd share! It took place in the 80s / early 90s and they covered several rivers along the Amazon basin. What really caught my attention is the ph and nitrate readings.

The study: ftp://daac.ornl.gov/data/lba/surf_hydro_and_water_chem/CAMREX/comp/Pre_LBA_CAMREX.pdf
The data: ftp://daac.ornl.gov/data/bluangel_harvest/camrex/data/chemistry/chemdata.txt



In the tables, you'll see that the Rio Negro has ph readings in the 4s!!!!

With nitrates, the highest reading I saw was for Rio Jurua at 22.8uM. I converted that as follows:

Nitrate (NO3) has a molecular mass of 62.0049 g/mol. So:

62mg/mmole = 62ug/umol
22.8uM = 22.8umol/L, so 22.8umol/L x 62ug/umol = 1414ug/L = 1.414mg/L.
Rounded off, this would be about 1.4mg/L, or 1.4ppm of nitrates (I think I did that right!)

That basically supports that nitrates are nonexistent in the wild. I still don't get how some guys justify having 40-80ppm in their tanks and saying it's ok

​

I'm not surprised by the pH readings on the Rio Negro. My boss at the New England Aquarium has been involved in a lot of research on that river and based all the amazon exhibits at the aquarium on it. He has brought the main exhibit down to 3.8 before and all of the fish acted normal save for a large rtc that stopped eating until the pH was brought back to over 4.0. Rtc also happen to be the only species in the tank that is not necessarily found in the Rio Negro.

 

[BillyBlanco]

Cool

 

[Mudslinger14]

That's awesome.

Of course the amazon is on a daily wc drip called rain.
So even all the manmade waste that's put into the river is diluted.
Cool study though

 

[Coues]

That ph reading shocks the hell out of me! The nitrates, not so much. VERY interesting stuff Jose, thanks for sharing that.
And as far as:

how some guys justify having 40-80ppm in their tanks and saying it's ok ;

It's just people trying to justify their laziness. Pure and simple.

 

[jcardona1]

Yeah I knew these blackwater rivers had really low ph, but man that is low! But even then, it's not like the ph of battery acid or vinegar lol. Different concentration of ions, so even though the ph is very low, fish can live in it just fine.

 

[ceeej31]

Yeah I knew these blackwater rivers had really low ph, but man that is low! But even then, it's not like the ph of battery acid or vinegar lol. Different concentration of ions, so even though the ph is very low, fish can live in it just fine.

Here's another neat fact, I've been told that the low pH also makes it harder for mosquitoes to breed properly, making the area around the river relatively bug free as compared to whitewater rivers like the amazon itself.

 

[peewee]

That ph reading shocks the hell out of me! The nitrates, not so much. VERY interesting stuff Jose, thanks for sharing that.
And as far as:

It's just people trying to justify their laziness. Pure and simple.

I 100% agree!

 

[Kribby]

That info is freaking awesome. I can't imagine keeping the pH in any of my aquariums that low.

 

[Younglin]

Interesting study. This should be a sticky.