Nitrate reduction

[ammari33]

Hi
My tank has just completed the cycle, however, I knew from this forum that Nitrate can only be reduced by water change!
Now, here is my doubt
I noticed that Nitrate was reduced from 80 PPM to 0 PPM without water change just alone, is this possible?!
The results from one week ago

Today's results

 

[Reefing Madness]

Wow. You have a macro algae sump or a ton of live rock?

 

[ammari33]

No, just the cycle completed, fish less cycle, dry rocks (only seeded with a small piece live rock may be 250g). I used raw jumbo shrimp 2.2 Ib
You can see the graph below

 

[Randy Holmes-Farley Verified Community Expert]

Hi
My tank has just completed the cycle, however, I knew from this forum that Nitrate can only be reduced by water change!

Well, I hope that wasn't this specific forum (Reef Chemistry Forum) since it isn't necessarily true.

An 80 ppm drop in nitrate in one week seems improbable, however.

I expect the issue is the nitrite. With some nitrate kits (Salifert for sure, possibly others) a small amount of nitrite shows up as a lot of nitrate.

Since you had elevated nitrite in the first test and not in the second, I expect that the first nitrate reading was in error, and now you are seeing the actual amount of nitrate which may be somewhere between 0 and 5 ppm (although nitrate testing is notoriously inaccurate anway).

 

[ammari33]

Sorry I did a mistake in uploading the graph, this is the right graph for Nitrate

 

[LetItReef]

No, just the cycle completed, fish less cycle, dry rocks (only seeded with a small piece live rock may be 250g). I used raw jumbo shrimp 2.2 Ib 
You can see the graph below

2.2 lb jumbo shrimp, what size is your tank?

 

[Randy Holmes-Farley Verified Community Expert]

Wow, I didn't see that. One is usually enough.

 

[ammari33]

700G DT & 350 G Sump

 

[ammari33]

In fact I started with one jumbo shrimp, however, the ammonia was increased to only 0.5 PPM for almost one month. From the graph on Sep 8, I added 2.2Ib and you can see the jump in Ammonia

 

[Randy Holmes-Farley Verified Community Expert]

If there is any shrimp left, I'd remove it now.

 

[ammari33]

Thanks, I will do

 

[Daniel@R2R Verified Admin]

That's a HUGE tank!! I want pics!!

 

[ammari33]

That's a HUGE tank!! I want pics!!

Here we go

 

[DRThompson]

from the pic I'd say the algae on the rocks ate your nitrates

 

[ammari33]

You are right .. Maybe this is the reason