NO3 on a brand new tank

Ciwyn · Aug 26, 2018

So I finally have my new big tank set up. I added rock last week. The rock consists of about 100# of BRS pukani and another 50# of reef saver rock from an old tank that had dried out before recuring. All of this rock has been curing in 2 separate tubs for nearly 8 months.

The PO4 on both tubs was just below .10 ppm checked with a hanna checker before the rock was placed in the tank. The NO3 on both tubs was showing ~10.

After I aquascaped and added 80# of rinsed sand I wanted to check the parameters. I am under the impression that since the rock had been curing for quite some time with a piece of live rock from my existing tank that essentially the rock I placed in the tank is already live and will have not much if any of a cycle.

The PO4 came back as .02 almost exactly what I would expect adding this rock to a much larger water volume. However, when I checked the NO3 I got a much different reading. The salifert test showed the NO3 at what honestly looked like 100 ppm. Seeing as that doesn't seem possible to me I then used a Nyos test kit. This test shows the nitrate at ~40 ppm which again when the rock was testing at 10 ppm in the curing tub this makes no sense. Finally I used an old API test to get a 3rd reading. The reagents had both expired in the past few months but its at least a 3rd reading. This test looked like ~40 ppm as well (this one is so hard to read.)

So the salifert reading appears to be erroneous especially because it shows a similar reading on my old display tank. However it showed what seemed like an accurate reading on the curing tubs with the rock in them.

I am just trying to figure out how a tank that was just filled with new salt water and had rock placed in it could have a nitrate reading that high so quickly. Especially considering the rock went from a 30 gallon trash can to a 350 gallon aquarium. The rock has only been in a few days but there are no signs of algae yet and the skimmer is not pulling any organic matter yet either.

I would like to get this figured out before I start adding livestock to the tank. Want to make sure a tank this size gets started on the right foot. Any insight would be appreciated.

Thanks

PS An additional oddity I experienced with the 50# of reef saver rock in the last tank it was in which I was never able to solve. That tank had a horrendous hair algae problem. I was never able to get it under control for 2 years. Whenever I would test the water on it both the NO3 and PO4 always read 0 as well. Never changed. However hair algae continued to grow out of control. I would pull half a 5 gallon bucket out of the tank and it would be back in a week. I believe whatever caused that problem with the tank is solved because during the curing of that rock I was able to get actual NO3 and PO4 readings during the cure. I just definitely don't want a repeat of that disaster.

Diesel · Aug 26, 2018

If nothing is added to the tank it just simple that the rock is releasing the No3.
In a way it’s good as your cycling is working.
Just to be sure take a ammonia and nitrite test.
With a high nitrate pretty sure that both test come in low or undetectable.
All you can do is trying to get the nitrate under control by adding some bacteria or using some macro algae.
Remember 40ppm isn’t that bad for a new tank and more than normal imo.

Ciwyn · Aug 26, 2018

Well that's a positive side to this. To think I thought I had a decent understanding of all this. lol

I may have to get an ammonia test. I've always kind of thought (perhaps incorrectly again) that if you had rising NO3 then it was a safe assumption you would not have ammonia or nitrite.

Guess I'll do a couple water changes this week and see what happens. I also did add some chaeto to the sump but that was mostly to get the pod population started.

Diesel · Aug 26, 2018

Ciwyn said:
Well that's a positive side to this. To think I thought I had a decent understanding of all this. lol

I may have to get an ammonia test. I've always kind of thought (perhaps incorrectly again) that if you had rising NO3 then it was a safe assumption you would not have ammonia or nitrite.

Guess I'll do a couple water changes this week and see what happens. I also did add some chaeto to the sump but that was mostly to get the pod population started.

Great work so far.
Yes you right if No3 is present that No2 and ammonia is low or just not there.
The fact that you cured your rock for 8 months it will help you on the cycle process.
Make your chaeto work for you put a good light above it.

Ciwyn · Aug 26, 2018

Yeah, I just want to make sure everything is set up properly on a tank this size. My old display tank is going through a few issues (it ran quite nicely for several years though. I equate the current issues to an old sand bed getting disturbed when I moved last year and chloromines in the new water supply). I have changed out my RODI filters to deal with the chloromines so hopefully there are no issues with those on the new tank.

Ciwyn · Aug 26, 2018

Also, what may be the cause of the very high reading on the salifert test?

Diesel · Aug 26, 2018

User error or expirered test kit.

Ciwyn · Aug 26, 2018

Well its definitely not expired. Expires in 2020 and I did the test the way the directions state. 4 drops of the liquid and one pressed spoonful of the powder, swirl for 30 seconds and wait 3 minutes, then I view it near a window for the diffuse daylight.

Diesel · Aug 26, 2018

If you measure with one test kit 40ppm and the other 100pmm there must be something wrong either with the kit or how you use it.
I had kits that I had delivered with a ok date and yet it was way off.
Order either a ATI or Triton ICP test to be sure where you are on all your elements.

Lasse · Aug 26, 2018

You do not have NO3 levels as high as you read from the test. These test that you use transfer all NO3 into NO2 and after that NO2 is analyzed and the colour chart transform the result back into NO3. But this means that if there is No2 already in the water - you will have a false reading. The multiplication factor is normally between 50 and 100 - according to brand of the test you use. If you have 1 ppm NO2 in your water when you test for NO3 - you will have a reading of around 100 ppm as NO3 if the conversion factor is 100. I do not know the conversion factors for Salifert or Nyos. But your result indicates that Salifert have a higher conversion factor compared with Nyos. IMO - it is total pointless to test NO3 before the tank is fully cycled (not before NO2 is absent )

Sincerely Lasse

Randy Holmes-Farley · Aug 26, 2018

Right. Don’t bother testing for nitrate if you have detectable nitrite. The nitrate will read false high. The amount may vary by kit design, but 0.1 ppm nitrite can read as 10 ppm nitrate.

Ciwyn · Aug 26, 2018

Well that is interesting for the nitrite correlation. I never understood a reason to test for nitrite because I thought the presence of nitrate on a test would indicate nitrite was zero.

Ciwyn · Aug 31, 2018

So I tested nitrite the other day and it was definitely showing zero. The nitrate test was more what I’d expect though. Somewhere between 10-25. Very difficult for me to tell the difference between those 2 readings.

beaslbob · Aug 31, 2018

It is possible with plant life like algae on the rocks, the tank is producing ammonia which is being consumed by the algae. And the algae is using the ammonia for nitrogen not nitrates. Hence you can have nitrates.

As bacteria build up and consume the ammonia, the algae will start consuming nitrates and nitrates will drop down.

my .02

Ciwyn · Oct 2, 2018

beaslbob said:
It is possible with plant life like algae on the rocks, the tank is producing ammonia which is being consumed by the algae. And the algae is using the ammonia for nitrogen not nitrates. Hence you can have nitrates.

As bacteria build up and consume the ammonia, the algae will start consuming nitrates and nitrates will drop down.

my .02

Well this tank was started brand new from dry rock (mostly pukani which had been curing for about 6 months and seeded with a piece of live rock from my other tank) so there really wasn't any algae in the tank at that point.

As an update the nitrates appear to be somewhere in the 25-40 range, I really have a difficult time differentiating the values. I am beginning to see some hair algae beginning to form on some of the rock (I expected this as its common in a new tank). I'm going to do a fairly large water change later this week probably 60 gallons so 20%. Are there any other suggestions to keep this algae bloom to a minimum? This is my third tank set up and the first one went reasonably smooth, hair algae grew all over, but went away after a month or so. The second tank went horribly wrong somewhere and I never figured out a solution. The second tank was started with dry rock and never once showed any readings of nitrate or phosphate when I would check. Hair algae began growing on the rocks and all over the tank and would never cease. I would pull half a 5 gallon bucket out of the tank and it would be back in a week. It never stopped. Oh bubble algae also invaded as well. So I would very much like to avoid having that scenario happen again.

I am hopefully on a better track already due to the fact that nitrate and phosphate are detectable and in reasonable levels. Another path I was considering taking is I have the ability to tie the new system into the common sump with my old system (not the one that was a total disaster). Does that seem like a beneficial idea to help get my new system up and running?

So for the TL: DR version:

Nitrates holding 25-40
The uglies seem to be starting with some hair algae. Along with some water changes what would be some other good methods to keep it to a minimum?
Would tieing the new system into the common sump with the old system be beneficial? (old system will be taken down eventually)

Thanks!

IslandLifeReef · Oct 2, 2018

Well, if you haven't added anything living to the tank yet, I would just let it go. Eventually the algae will deplete the nutrients and die. Just leave it alone for a while.