High NO3, 0 Phos

[Jaymang]

Hi all! I recently started a small 2FT AIO frag tank. (Like to look over little frags compared to full on scapes )

Currently, I'm facing nutrient issues with the tank. My no3 is hovering 40 ~ 42ppm Hanna NO3 LR. (tested on salifert to cross check, looks like 25ppm). And my phosphates is at 0 according to Hanna *PPB*.

Tried dosing seachem flourish yesterday at 0.5mls to try to get my po4 to 0.01. Tried measuring today but it's still at 0.

My tank doesn't have any rock scape nor sand. Running skimmer 24/7. Sockless. Just lots of media (big chamber customed). Oh yes, I've tried carbon dosing for a week with vinegar but to no avail. I have very little algae in the tank aswell. Just small patches of brown diatom.

My hammers and test sps frag (yellow spondage) are looking good but my torches are suffering. Pretty lost ATM.

Thanks guys!

EDIT: I've noticed most of corals did pale out a little compared to when po4 was at 0.4. I am not running GFO & AC. Po4 swung downwards rapidly within a week as far as I know.

 

[Timfish]

ANything living will use phosphorus including biofilms and sponges. If you're testing low PO4 (< .03 mg/l) you'll need to add it and monitor it. To lower your nitrates I'd do more frequent water changes.

 

[BroccoliFarmer]

Tanks take of pohospahtes 4 times as fast as nitrates. As such, zero phoasphates means little nitrate uptake. You probably are staying at zero phosphates because your starving zooella and macros as sucking in the phosphate as much as they can as fast as they can (all you can eat buffet after a 30 day fast.how long it going to last).

dose more phosphates and monitor.

 

[Tamberav]

No point in carbon dosing when po4 is 0. Carbon dosing lowers Po4 as well with nitrate. Not just nitrate alone.

I would dose PO4 up. Depending on tanks usage, you may need to dose and test daily.

 

[Jaymang]

Tanks take of pohospahtes 4 times as fast as nitrates. As such, zero phoasphates means little nitrate uptake. You probably are staying at zero phosphates because your starving zooella and macros as sucking in the phosphate as much as they can as fast as they can (all you can eat buffet after a 30 day fast.how long it going to last).

dose more phosphates and monitor.

Funny thing is I don't run any ATS/Macroalgae in the tank. But thank you for your reply.

To all: thank you for your suggestions. Will continue to dose flourish and observe.

However, I'm just curious why does po4 bottom out (I have only a handful of frags and po4 dipped all of a sudden within 3 ~ 4 days), is this what they called different tank have different 'settings'?