What's wrong with my nitrates

[Danger_Chicken]

This has been boggling my mind for months. I've done this test at several water changes with the same results.
Nitrates:
Before water change - 10ppm
After water change - 20ppm
Out of tap - 5ppm

How can this be? I have mangroves in a refugium to bring nitrates down so I can make a twisted rationalization that's why they get lower. But why are they higher after a water change.

Thoughts? 220g, 30% water changes twice a week, heavy stock.

The flash has the colors off a little.

 

[zennzzo]

From those tests you have less nitrates before w/c...acording to those you need no water change...strange. Have you skipped w/c and read test?

 

[Danger_Chicken]

No I'll do that and see what happens. LOL I actually feel bad about changing the water now.

 

[syndicate]

lol wc making the nitrates worse thats not right

 

[dogofwar]

Either the tests not good or you sampled from different parts of the tank.

Water changes (with low nitrate water) are good. Do more and see what happens...

 

[zennzzo]

Also test with 10ml and double the drops...

 

[Cichlaholics Anonymous]

what test are you using for nitrates?

 

[Danger_Chicken]

Either the tests not good or you sampled from different parts of the tank.

Water changes (with low nitrate water) are good. Do more and see what happens...

I test from the same point everytime, I have a strong current in the and tank and waited an hour after teh water change to let it mix.

what test are you using for nitrates?

API drops

I'm going to check it every day this week and see what the results are.