Nitrates remain at 0 after scrubber is harvested...?

[Orion5]

Hi everyone,

My FW upflow algae scrubber gives thick green algae every 7 days. My nitrates have been 0 the whole time since the scrubber has been functioning, but I noticed something today.

Yesterday I harvested the scrubber, so I decided to test the water for nitrates today just for kicks. It's still at 0... Is there not normally a slight nitrate spike after a harvest, or have I tested too soon (24 hours)? I'm concerned that the plants may have been doing a lot of work that the scrubber should be doing. lol!

Thanks for any and all input.

Cheers!

[SantaMonica]

No it just depends on what the inputs are. If you are not feeding much then it may not spike.

[Orion5]

I'm over-feeding the fish somewhat because there are fry that should eat twice/day in order to grow more quickly, and no water changes.

I'm going to test the scrubber on a tank without plants to make sure it's working. Thanks for the input!