Aquaforest NO3 test turning red

[Aleph]

Hi guys I just bought an Aquaforest NO3 test kit, I just performed it on my tank and I got a strange result:

The color is bright red with heavy precipitation....
So after this result I tried the test on my rodi water and it didn't color at all which is correct since rodi should be at 0 nitrates.
Next try, 50% (0.5ml) tank water and 50% rodi, got this result:

Still bright red, much less precipitation.
Next, 10% tank water and 90% rodi:

Pinkish color, still way off from the strongest color in the scale.

So, from what I could understand, either I have 500+ nitrates (I was at around 30 with a salifert test two months ago) or something is interfering with the test. I have a suspect that I have metals in my tank (an ICP is on its way) because even with 30 nitrate I had some fish deaths and constant stn on all lps and sps (softies doing fine but not much growth), could some metal cause this result? Or could it be that I have high nitrites?

Thank you for the help!

 

[Bo.]

If anyone have problem with brown reagent B - please PM us your home address to get replacement.

What color is your reagent B? Looks like they had some trouble with quality last year.

 

[Azedenkae]

Hi guys I just bought an Aquaforest NO3 test kit, I just performed it on my tank and I got a strange result:

The color is bright red with heavy precipitation....
So after this result I tried the test on my rodi water and it didn't color at all which is correct since rodi should be at 0 nitrates.
Next try, 50% (0.5ml) tank water and 50% rodi, got this result:

Still bright red, much less precipitation.
Next, 10% tank water and 90% rodi:

Pinkish color, still way off from the strongest color in the scale.

So, from what I could understand, either I have 500+ nitrates (I was at around 30 with a salifert test two months ago) or something is interfering with the test. I have a suspect that I have metals in my tank (an ICP is on its way) because even with 30 nitrate I had some fish deaths and constant stn on all lps and sps (softies doing fine but not much growth), could some metal cause this result? Or could it be that I have high nitrites?

Thank you for the help!

Interesting. Can you check 100% RODI and see what it shows?

 

[Aleph]

Thanks guys!

@Bo Lin the B reagent is perfectly clear, I read there were some brown batches but it seems mine wasn't like that.

@Azedenkae the 100% rodi test shows no coloration at all, would you like a picture of the clear sample?

To follow up I did another test, I performed the test without adding the A reagent (the powder), just the B and the sample showed a slight color variation shown here:

Since, from what I read about how the test works, the powder converts nitrate into nitrites and then the B reagent makes the solution color up, would this be a proof of the presence of nitrites in the water? Could this explain the messed up results?
And, if I had in fact like 3 ppm nitrites, wouldn't everything be dead right now? Besides, this is an established tank so how could that even happen?

Thank you again for the help!

 

[Azedenkae]

Thanks guys!

@Bo Lin the B reagent is perfectly clear, I read there were some brown batches but it seems mine wasn't like that.

@Azedenkae the 100% rodi test shows no coloration at all, would you like a picture of the clear sample?

To follow up I did another test, I performed the test without adding the A reagent (the powder), just the B and the sample showed a slight color variation shown here:

Since, from what I read about how the test works, the powder converts nitrate into nitrites and then the B reagent makes the solution color up, would this be a proof of the presence of nitrites in the water? Could this explain the messed up results?
And, if I had in fact like 3 ppm nitrites, wouldn't everything be dead right now? Besides, this is an established tank so how could that even happen?

Thank you again for the help!

Nah all good, the RODI test is just a good negative control sanity check.

I am not familiar with how much nitrite affects the Aquaforest check, though I do know I had previously tested nitrite to be like 12ppm and nitrate only read a hundred or something max. Nonetheless, if there is really 3 nitrite, that's fine. No, everything would not be dead right now because nitrite don't affect marine fish the same way as freshwater fish: http://reefkeeping.com/issues/2005-06/rhf/index.php

Do you have a nitrite test? Can you measure nitrite and see what it is?

 

[Aleph]

Didn't know that, that's a very interesting read. I had the notion, widespread in italian lfs and forums, that even a very small concentration of nitrites was so toxic that would kill pretty much everything, good to know it's not that bad. Still, I'm experiencing systemic stn in both lps and sps, could that be due to this nitrite concentration?

About testing, I performed a tropic marin nitrite test yesterday but unfortunately it was expired so it might not be reliable, the result was 0.2 ppm...I wanted to get a nitrite test from a lfs but unfortunately we're on semi lockdown where I live so getting it now it's not that easy, I will try to order one online!

 

[Aleph]

Quick update, I managed to get a sera strip test, I know they are totally unreliable but unfortunately I will have to wait for the lockdown to end here to be able to go to a decent lfs. Anyway, for what is worth the result was 0 nitrites (no coloration) >250 nitrates. If I had nitrites that high, shouldn't it color up at least a little? Anyway, I guess I'm stuck until I can get a better test.

Could some metal contamination kill denitrifying bacteria causing an abnormal nitrates build up?

 

[Aqua Man]

@Aleph

what salt mix are you using?

Test the new salt water after following mixing instructions.

 

[Aleph]

Aqua Man thanks for the suggestion, the salt mix I use is Red Sea Coral Pro and I've already done this test, no coloration at all from the test...I also tested nitrates in the tank before and after a water change and they drop as much as they should...
Also for some time I did something like 25% water changes per week and everything got better, nitrates got down and stn stopped, but unfortunately it's a schedule that I can't maintain for long. As soon as I highlight the problem I will make a big water change to reset everything but before I want to understand what's the problem otherwise it will return again in the next months.

 

[Aqua Man]

no coloration at all from the test...

That’s good!
having nitrites will effect the results of nitrates.

Nitrites in Freshwater systems is really bad. Not preferred but, Nitrites in a Saltwater system is ok.

why do you suspect metal? Running some activated carbon and a poly filter will help remove contaminates.

water change brought nitrate down, then went back up. Are you feeding a lot?

 

[Aleph]

I suspect metal for several reasons:

-I have a very low organic load and an oversized skimmer (bubble magus a5) ,only 2 clowns in a 20g that I feed only once a day with very few pellets, still high nitrates and no algae

-constant cyanobacteria issues, no matter what I do, dose bacteria, chemiclean, almost no feeding, daily removal, they always come back

- had 3 fish death in a few months, I though about some parasite at first but the clowns are fine so maybe they are more tolerant?

- stn on all lps/sps in all light and flow conditions, even with direct feeding (softies are fine but growth is very slow)

Metal contamination is the only explanation I could come up with, but maybe it's something else I cannot see now...I sent an ICP two weeks ago but still didn't get the results.

 

[Aleph]

Oh I forgot to add, I've been running cuprisorb and carbon and dosing stability for a week, still no changes but I guess it's too soon!

 

[Aleph]

Ok, the ICP results have arrived, all parameters are within range except for tin that has a value of 10.4 ug/l ... from what I can tell reading some threads on the forum it's difficult to tell if this level of tin can be a problem or not, it seems unlikely to me that it could interfere with the test results...could it have an impact on the bacterial population?

 

[Randy Holmes-Farley]

FWIW, I do not have any good idea of what the precipitate is or why you have it.

I think the most likely answer is a problem with the kit reagents, rather than something in the tank water.

I would not worry about that tin level unless the aquarium is clearly suffering.

 

[Aleph]

Thank you for your reply! Well the aquarium IS suffering actually, I have had stn on all lps and sps and constantly high nitrates in the last year and I cannot understand the cause, so I thought that metals could at least partly explain what was happening...

 

[Randy Holmes-Farley]

Thank you for your reply! Well the aquarium IS suffering actually, I have had stn on all lps and sps and constantly high nitrates in the last year and I cannot understand the cause, so I thought that metals could at least partly explain what was happening...

While elevated metals might impact the tank, I don't know how they impact the nitrate test. IMO, they would have to be really abnormally high to do such a thing.

Trace metals are, by definition, present only at very low levels. There isn't close to enough to give "heavy" precipitation in a test.

 

[Shirak]

Can you take some tank shots in white light? Are you getting much algae and coralline algae growth? Have you tested phosphates?

 

[Aleph]

Randy that makes sense, thank you!

Shirak I can take a picture tomorrow, it's past lights out now, I have normal coralline growth, zero algae and lots of cyanobacteria, I always had them since the first few months of the tanks and now two years in I still have them and can't get rid of them.
Phosphates always tested zero with tropic marine kit and also just got tested with the icp, they were at 0.02. I even dosed them for some time suspecting that I was phosphate limited but unfortunately that didn't help in bringing down the nitrates, if anything it helped the cyanobacteria, as expected...I also carbon dosed for a few months but no results at all...

 

[Shirak]

Randy that makes sense, thank you!

Shirak I can take a picture tomorrow, it's past lights out now, I have normal coralline growth, zero algae and lots of cyanobacteria, I always had them since the first few months of the tanks and now two years in I still have them and can't get rid of them.
Phosphates always tested zero with tropic marine kit and also just got tested with the icp, they were at 0.02. I even dosed them for some time suspecting that I was phosphate limited but unfortunately that didn't help in bringing down the nitrates, if anything it helped the cyanobacteria, as expected...I also carbon dosed for a few months but no results at all...

Yeah I wouldn't necessarily trust nutrient results like phosphate on ICP because of the time in the vial to testing and what can happen to organics in the interim. How old is the tank? Did you start with all new dry rock and sand? Perhaps they are absorbing the phosphate if the tank isn't that old yet?

My thought was phosphate limited also, which allows nitrate to build as algae and bacteria and zooxanthellae are unable to process the nitrates in it's absence. This could certainly cause a problem with photosynthetic coral health as most of their nutrition comes from zooxanthellae.

 

[Aleph]

The tank is about two years old, it started with dry and a few seed live rocks, no sand.
About the phosphates, I even dosed them for a few months when nitrates measured in the 30-50 with a salifert test, I dosed about 0.02 a day and regularly measured with the tropic marin test kit. There was no nitrate reduction and in the end I also tried adding a bit of carbon dosing (diy nopox) and got a huge cyanobacteria bloom.
My guess then was the the cyanobacteria was using the phosphate more efficiently than the "good" bacterial population and when the tank got stable again did a chemiclean cycle followed by bacteria dosing (mb7), but the cyano came back and the nitrate remained in the 30-50 range.
Honestly I don't know what else I could try.