Newly made saltwater has nitrates?

[pdiehm]

I just made 10 gallons of new saltwater to my biocube because a new hermit crab I got and added yesterday is apparently dead.

I tested the tank water using red sea nitrate test (marine care program) and the test was probably 30ish prior to the 50% change. On Tuesday morning, I did about a 95% water change and my nitrate reading was about 30ppm (it's hard to tell because of the darn colors and my colors almost never match the card).

I tested the new saltwater and the nitrate level was almost identical to that in the biocube. I did have to have a nitrate pad in my cichlid tank because our tap water contains about 10ppm nitrates in it.

Now is this something I will have to account for and dose with vinegar or a product like AZ-NO3 or the Red Sea equivalent or is it something that I can account for and adjust my test reading accordingly?

 

[Randy Holmes-Farley]

If you are using RO/DI water and any quality brand of salt mix, you do not really have 30 ppm of nitrate in new salt water, and the testing is in error.

What salt mix are you using?

 

[pdiehm]

It is IO reef crystals.

Now, I do use the marine care kit from Red Sea and discerning the colors is one of the more complicated things that I have come across.

The color I get is a not red (50ppm), more of a dark pinkish, almost purple color.

I just read that you can do a high range test using 4 ml rodi and 1 ml saltwater and multiply by 5.

I do know my tap water has roughly 10ppm nitrates.

As for saltwater test on the new batch, this is the process. 5ml water, 5 drops of solution A, shake for 10 seconds, 1 scoop of powder B, shake for 1 minute, and a scoop of powder C. Shake for 10 seconds. 9 minutes and color read.

Test kit is brand new (within 1 week).

I have a Red Sea pro test kit on the way because of interpreting the colors, hoping this makes it easier to read. But make no mistake, I absolutely had a substantial nitrate reading in newly made saltwater.

 

[Randy Holmes-Farley]

FWIW, I wouldn't use tap water, but how do you know it has 10 ppm nitrate? From your water company report, or your test kit?

The Reef Crystals itself doesn't have enough nitrate in it to be significant.

 

[pdiehm]

I remember testing the tap water when I had my cichlid tank up and running because I was always getting high nitrate readings (around 40ppm). My test revealed approximately 10ppm of nitrates (Bear, DE).

I don't use tapwater for my saltwater. I have a 6 stage BRS RODI system. 0 TDS (tested that too with my handheld checker, and the inline TDS).

 

[Randy Holmes-Farley]

Then if you use RO/DI and Reef Crystals, a high nitrate reading in the new salt water is a testing error.

 

[pdiehm]

I'm not sure how. I'm following the red sea nitrate test instructions to the letter.

Fill 5ml of water
put 5 drops of reagent a
shake for 10 seconds
put 1 scoop of reagent B powder
shake for 1 minute
put 1 scoop of reagent c powder
shake for 10 seconds
Let sit for 9 minutes, read the color

 

[pdiehm]

Ok. I contacted someone at Red Sea, and got some clarification about my process.

I need to shake the vials vigorously after B and C are added. I did that for these 3 tests.

BioCube 29 = roughly 15ppm (not as light as the 10, but not as dark as the 20)
120 Gallon Main Display = Almost purple over 50ppm, so they recommended a high range test (1ml saltwater, 4ml rodi and multiply by 5). Result: Approximately 75ppm
New Saltwater = 0ppm

Apparently when they mean vigorously, they mean VIGOROUSLY

 

[Randy Holmes-Farley]

Nitrate testing is also notoriously inaccurate relative to other test methods we use.
It is a tricky test to develop, and is prone to certain errors (such as a little nitrite showing as a lot of nitrate with some of them).

In any case, don't worry about the new water. Whether the tank itself has a nitrate problem is more difficult to know.

Let us know what you find with more vigorous shaking.

 

[pdiehm]

haha, I found the test colors were more accurate than before. it's a baseline and now i can adjust from there.

 

[Randy Holmes-Farley]

OK sounds good.

Happy reefing.

 

[pdiehm]

indeed. have a feeling this isnt the last time I'm going to make something this simple into an overly complicated problem.

 

[chefjpaul]

indeed. have a feeling this isnt the last time I'm going to make something this simple into an overly complicated problem.

Hahaha!
Welcome to the reef keeping hobby.
Thats how we all learn, fortunately we have great people here to learn from, that listen.

 

[Smarkow]

indeed. have a feeling this isnt the last time I'm going to make something this simple into an overly complicated problem.

Coming to this thread 5 years later from a link, and it is still useful knowledge for us all

 

[Paulwizal23]

Depends when you are mixing and making your new batch,
Make sure your bucket and pumps are clean, no plug in candle scents, or cat liter anywhere buy where the new water is being mixed. I have heard of this before.