Measuring nitrate large swings?

[PeterEde]

I've bee measuring daily until I get numbers I'm happy with.
I'm down from 40+ to 18ish but some days I get a 10ppm increase. Never a 10ppm decrease.
Is it possible or more likely a Hanna reagent issue?
Yesterday I was 18.2 today 28.3?

 

[BroccoliFarmer]

I've bee measuring daily until I get numbers I'm happy with.
I'm down from 40+ to 18ish but some days I get a 10ppm increase. Never a 10ppm decrease.
Is it possible or more likely a Hanna reagent issue?
Yesterday I was 18.2 today 28.3?

Need a little more information. Can you get a 10 point swing on the up or down...yes. On the upside it is either too much feeding, your protein skimmer runneth over or something died. On the down side...are you carbon dosing? Do you have a refugium? I have seen some pretty good down side swings with my fuge but was when I had a lot of macro algae and I was running my fuge light 24/7.

One thing to consider...good old human error. Clean cuvette. using all of the Reagent. Not waiting the 7 minutes for the nitrate to mature.

 

[PeterEde]

Need a little more information. Can you get a 10 point swing on the up or down...yes. On the upside it is either too much feeding, your protein skimmer runneth over or something died. On the down side...are you carbon dosing? Do you have a refugium? I have seen some pretty good down side swings with my fuge but was when I had a lot of macro algae and I was running my fuge light 24/7.

One thing to consider...good old human error. Clean cuvette. using all of the Reagent. Not waiting the 7 minutes for the nitrate to mature.

It's possible over feeding. Coming off a Sunday home possibly fed more.
I am carbon dosing and have fuge.
Always rinse cuvette with tank water.
Timed 2 minute shake and always time the 7 minutes.
I'll see what numbers I get tomorrow and watch for next Monday

 

[Randy Holmes-Farley Verified Community Expert]

I've bee measuring daily until I get numbers I'm happy with.
I'm down from 40+ to 18ish but some days I get a 10ppm increase. Never a 10ppm decrease.
Is it possible or more likely a Hanna reagent issue?
Yesterday I was 18.2 today 28.3?

Which Hanna checker?

 

[PeterEde]

Which Hanna checker?

Hr Nitrate
Randomly I get +10ppm above previous.
Just seems odd.
Maybe due to weekend feeding.
No one home mon-fri so feeds are less

 

[Randy Holmes-Farley Verified Community Expert]

Hr Nitrate
Randomly I get +10ppm above previous.
Just seems odd.
Maybe due to weekend feeding.
No one home mon-fri so feeds are less

It could be that, or it might be random test error.

 

[moorjames]

I get pretty huge swings when I change my filter out. I use a polish pad along with those White and Blue sponges in my Bio Cube 32 gallon- and usually will leave the filter in there for 3-4 days. When I change it- my nitrates swing pretty big since that is mostly the source of nitrates. But if I change them out too quickly- my water is too clean and then I bottom out... still trying to figure mine out too lol

 

[PeterEde]

Went up a few points today too.
I did just add 10 ghost shrimp and a nem