ATS bringing NO3 too low??

Reefcowboy · Jan 18, 2019

I have a 150 sps tank with around 14 fish or so. 5 small-medium tangs(5”), clowns,foxface, cardinals. Tank has been set up for 7+ months.
Have a custom ATS with a 12x8” screen lit on both sides with 3x red led bars each side(pics).

Tank has been doing great with algae harvested every saturday. Lights Stay on from 10pm til noon(14 hrs). I feed around 10 cubes of frozen varied foods (evening)and have an automated feeder feeding pellets 4times a day(small qty).

My No3 had been at 4ppm for the past few months. I noticed however this week some montis getting a bit pale, similarly to when I used to dose carbon. Polyps dont quite come out, piece looks pale. Other montis in the tank look great, no change. Lighting are MH’s ran for as long as the tank has been set up, no change on any other variables, many corals growing a showing good color.

I tested my nitrate three days this week and it read 0.25ppm(red sea nitrate pro).
Can my ATS be sucking too much nitrate? I would prefer it to be at around 4-6ppm...
Should I cut the lighting cycle? Feed even more? Thanks

EmdeReef · Jan 18, 2019

It's possible, try reducing the photoperiod to 10-12hrs and see if that works. IMO feeding more is always a great option :) but watch the phosphates.

Scrubber_steve · Jan 18, 2019

Yes, reduce the ATS photo period. Reducing the time the unit is photosynthesising reduces the amount of nitrogen assimilated, & vice versa

Reefcowboy · Jan 19, 2019

Thanks guys, I figured photoperiod would be the adjustment to go to.
I'm just amazed how efficient an ATS can be. Thought it would process nitrates to low amounts but never below 1ppm!

Reefcowboy · Jan 28, 2019

So I lowered the photoperiod from 14 to 10 hrs, No3 still at 0.5 ppm...
Ive been dosing AcroPower to keep nutrients up, colors are ok.

Some sensitive montis def show a more pale color, but 95% of the sps seem normal/colorful. Funny thing; I had brought in some bubble algae in the system with a frag a few months ago, and knew of a few hidden spots where I knew a few bubbles were...lately noticed everything is gone. Cant find a single BA in the whole tank. Could this ATS be starving all other algae?

Scrubber_steve · Jan 28, 2019

Reefcowboy said:
So I lowered the photoperiod from 14 to 10 hrs, No3 still at 0.5 ppm...

feed the fish an extra time/day. The no3 has to increase with a shorter photoperiod duration.

Reefcowboy said:
I had brought in some bubble algae in the system with a frag a few months ago, and knew of a few hidden spots where I knew a few bubbles were...lately noticed everything is gone. Cant find a single BA in the whole tank. Could this ATS be starving all other algae?

Yes