Zero Phosphate and Aragonite

[BradVol]

My reef is about 5 months old. First reef tank so there's been a lot of learning. I've had an issue for at least 2 months now where most of my LPS have receded and stay deflated. A couple have died from polyp bailout. I'm very diligent about testing and dosing and doing everything best I can, but with my best efforts to keep parameters stable I haven't had any luck getting the coral to improve.

Finally I realized from reading a lot that my phosphate could be the main issue. I have a Hanna ULR and it's read 0.00 on every test for the last 2 months. I've had some cyano and some algae so I figured there was enough phosphate to be ok, but now I think not.

I used new CaribSea Aragonite Special Grade and I'm thinking after some reading that it's taking up all the phosphate, hurting the coral. I've turned off my skimmer, took out the filter floss, no more GFO, and just letting the system go for a bit. But even after 2 weeks phosphate is still 0.0. Nitrate at 5-10.

I have some Seachem Flourish and started dosing that at .5mL per 20 gallons the last 2 days. I bought PE Mysis and Oyster Feast to help add phosphate. I'm feeding a bit more and adding in flake food. I also got another fish in QT to raise bio load a bit (5 fish in 34g).

My concern is that there is so much capacity in the Aragonite to bind phosphate that I could still be far away from getting measurable phosphate.

I'm looking for input on how to handle this. Do I dose, and if so what, how much, and got often? Do I need to quickly get all the phosphate capacity bound up or slowly? I prefer doing things naturally but maybe this is an exception. Do I leave my skimmer off or run it? Or is there something else I should consider?

Salinity 34ppm
Alk 9-10
Ca 425-450
Mg 1350-1400
Nitrate 5-10
Temp 78F
pH 7.8-8.0

 

[laverda]

Why were you running GFO? What was your phosphates at before GFO? Stopping GFO was a good choice.

 

[taricha]

I tested my bag of Caribsea aragonite and found that it contributed modest phosphorus (a good thing IMO). So it may not be such an uphill climb to get testable PO4.
You'll just have to feed/dose and monitor. With a hanna ULR kit if you actually want to distinguish "low" from "too low"

 

[Randy Holmes-Farley]

Yes, dosing sodium phosphate, potassium phosphate, or a commercial hobby product is a good plan.

I'd dose the equivalent of 0.03 ppm daily, and it may take a while for the phosphate to show up detectable.

 

[BradVol]

I was running GFO because I thought I was supposed to. Just a mistake from being new and reading on the internet. The highest phosphate I have ever measured was 0.01. I measured my BB QT tank and it was 0.06 so I feel good that I'm testing correctly.

Randy, I'll put together a plan to do that. I really appreciate the input. I was going to guess 0.03 per day but it was just a guess. Always appreciate your input.

 

[Backreefing]

I’m in a similar situation . I started doseing potassium phosphate. Enough for my aquarium to be.150 , but it’s always.020-.030 . It’s been a roller coaster finding a steady doseage and my whole aquarium is in a state of crash. Eventually I’m optimistic about the outcome.
I would go slowly even if nothing is showing. And I have found phosphate is a moveing target hard to get right . I’m told the rock will stop adsorption for me it’s a month and it’s not slowing down yet . Good luck.

 

[BradVol]

I’m in a similar situation . I started doseing potassium phosphate. Enough for my aquarium to be.150 , but it’s always.020-.030 . It’s been a roller coaster finding a steady doseage and my whole aquarium is in a state of crash. Eventually I’m optimistic about the outcome.
I would go slowly even if nothing is showing. And I have found phosphate is a moveing target hard to get right . I’m told the rock will stop adsorption for me it’s a month and it’s not slowing down yet . Good luck.

What do you think is absorbing it in your tank? I used the Aragonite and Marco Reef Saver Rock. I don't know if the rock I have absorbs it or not.

Once I read how much it can absorb I figured it could take a long time.

I feel better though because I'm more confident than I have been in some time that I'm on the right track.

 

[BradVol]

Oh, should I be running my skimmer during this process until my phosphates are detectable or leave it off?

 

[Backreefing]

For me its new rock and new aragonite gravel added after a tank upgrade. Maybe 30-40% new rock and 50% new gravel . The aquarium was awesome until I rescaped with some new rock.

 

[Vwluv10338]

You sure it was cyano and not dinos? I had dinos when my numbers hit zero. I turned off the skimmer and dosed nitrate and phosphate till they came back up

 

[BradVol]

You sure it was cyano and not dinos? I had dinos when my numbers hit zero. I turned off the skimmer and dosed nitrate and phosphate till they came back up

Yeah, pretty confident it was cyano. And it's gotten a lot better.

 

[Randy Holmes-Farley]

Oh, should I be running my skimmer during this process until my phosphates are detectable or leave it off?

I'd run a skimmer independent of phosphate being high or low or normal.

 

[BradVol]

I'd run a skimmer independent of phosphate being high or low or normal.

My concern was that it would remove some of the organic phosphate, but my knowledge is limited. Would the skimmer not affect the overall phosphate level? Thanks again for taking the time to reply. Greatly appreciated.

 

[Randy Holmes-Farley]

My concern was that it would remove some of the organic phosphate, but my knowledge is limited. Would the skimmer not affect the overall phosphate level? Thanks again for taking the time to reply. Greatly appreciated.

It might, but you can easily offset that with dosing and the benefits of the skimmer for aeration alone are substantial in most aquaria. Almost no reef aquaria are completely aerated. Unless there is zero pH swing day to night, aeration is incomplete. I've never seen a single reef tank that showed that.

 

[BradVol]

I always get frustrated when I search and find a thread that applies to me but there's no info on the back end about what happened and what worked, so I'll try to update this.

I'm dosing Seachem Flourish Phosphorous at 0.03 ppm per day. It was the only thing I could get locally and didn't want to wait for something to ship. But it works. I've upped my feeding. And I'm mixing it up with things I haven't used before: Oyster Feast one day, PE Mysis frozen another, and my regular mix of fish and coral food otherwise.

Today for the first time in months I had a measurable phosphate reading and have 0.03 ppm. I'm going to keep the dosing going and check again in several days and see where we are.

I have 4 LPS that have really been struggling. 2 have definitely improved already. The other two look slightly better. They could be the same but they're definitely not worse.

 

[Daddy-o]

Do you have fish? You could try feeding more and if possible adding more fish.
Cheers! Mark