skeptical of nitrAte readings

[James_in_MN]

I've recently made a change from Aqueon Quietflows to AquaClears on my 20g and 10g tanks. I have another filter in both tanks and seeded the new AC filters with some media from the Quietflows, so I didn't see a mini-cycle since the change. The odd thing is, I'm seeing a substantial drop in nitrAte readings.

10g tank
past: 20ppm nitrAtes prior to weekly water change
present: 5ppm nitrAtes prior to weekly water change
that'w with two sparkling gouramis added during changeover!

20g tank
past: 30-35ppm nitrAtes prior to weekly water change
present: 20ppm nitrAtes prior to weekly water change
added 4 miniature swords during change

I always was suspicious of the biological filtration on the Quietflows, but couldn't imagine that dramatic a change to the nitrAte readings. Could there be another reason for this change?

 

[ejaramillo01]

I've recently made a change from Aqueon Quietflows to AquaClears on my 20g and 10g tanks. I have another filter in both tanks and seeded the new AC filters with some media from the Quietflows, so I didn't see a mini-cycle since the change. The odd thing is, I'm seeing a substantial drop in nitrAte readings.

10g tank
past: 20ppm nitrAtes prior to weekly water change
present: 5ppm nitrAtes prior to weekly water change
that'w with two sparkling gouramis added during changeover!

20g tank
past: 30-35ppm nitrAtes prior to weekly water change
present: 20ppm nitrAtes prior to weekly water change
added 4 miniature swords during change

I always was suspicious of the biological filtration on the Quietflows, but couldn't imagine that dramatic a change to the nitrAte readings. Could there be another reason for this change?

I really don't know, but I experienced the same when I switch a 26g from an Aquaeon filter to a Canister filter. Before the switch, I was doing PWC twice a week, because I was getting Nitrates close to 40 ppm in three or 4 days. After the switch, I was reading 20 to 30 ppm of nitrates in 7 days. So , I started to do PWC once a week with the canister filter.

 

[rich311k]

Could be lots of factors, the filter is working better, there may have been nitrates in your tap, you could be feeding less, the test may be less accurate than it was. Does not really matter, change 50% a week and it is a non issue.