Unbelievably high Phosphates

Rowboman · Jan 29, 2023

So last night I did my weekly phosphate test and got a reading of 0.5. This is over 3 times the highest reading I’ve ever had on this tank!! I normally run under 0.1 and actually have to dose phosphates and nitrates occasionally because they tend to bottom out. I added GFO to
My carbon reactor, did my weekly 15% water change, and tested again today. I read 2.3!!!!! This is measured with a Hanna Low Range checker (not the better ULR). Is it possible my checkers malfunctioning? None of my corals, including my acros, seem worse for wear which seems impossible at a ppm of 2.3

Parameters
DKh=7.5 (apparently my kalk doser hose fell off so it didn’t dose for a day and a half. Currently fixing that slowly because I usually run 9 dKh)

Salinity 1.026

Nitrate=10.2 ppm

Calcium=436

Magnesium=1450

Temp=77.5-78

Big G · Jan 29, 2023

Before taking action, you may want to read this excellent article by @Randy Holmes-Farley

Aquarium Chemistry: Phosphate And Math: Yes You Need To Understand Both

Foods are by far the most important source of phosphate in most aquariums. In considering whether sources of phosphate other than foods are important, one must carefully look to the actual amounts involved to determine whether other sources are even worth trying to minimize.

reefs.com

Quietman · Jan 29, 2023

There's also this https://reefkeeping.com/issues/2005-01/rhf/index.php#15 from RHF. Kalkwasser will precipitate out phosphate so it might have been indicator of kalk issue and not another problem. Regardless, I'd fix the kalk and alkalinity then see where you are before trying other fixes.

Rowboman · Jan 29, 2023

Big G said:
Before taking action, you may want to read this excellent article by @Randy Holmes-Farley

Aquarium Chemistry: Phosphate And Math: Yes You Need To Understand Both

Foods are by far the most important source of phosphate in most aquariums. In considering whether sources of phosphate other than foods are important, one must carefully look to the actual amounts involved to determine whether other sources are even worth trying to minimize.

reefs.com

I actually already read it but thanks. It’s part of the reason I didn’t panic about the 0.5 ppm reading last night since I had just fed reef roids before testing and figured the residual food was still in the water column throwing off the test. But unless I dumped a lb of reef roids in the 2.3 ppm reading doesn’t add up

Rowboman · Jan 29, 2023

Quietman said:
There's also this https://reefkeeping.com/issues/2005-01/rhf/index.php#15 from RHF. Kalkwasser will precipitate out phosphate so it might have been indicator of kalk issue and not another problem. Regardless, I'd fix the kalk and alkalinity then see where you are before trying other fixes.

That’s actually super interesting and might help explain the growing algae problems I was having in weeks prior to this despite fairly low phosphate levels. But my Ph also dropped from its normal 8.3 to 8.0 when the kalk doser stopped working, which according to that article could lead to the phosphate bound up in the substrate leaching back into the water column

Placenta89 · Feb 16, 2023

Rowboman said:
So last night I did my weekly phosphate test and got a reading of 0.5. This is over 3 times the highest reading I’ve ever had on this tank!! I normally run under 0.1 and actually have to dose phosphates and nitrates occasionally because they tend to bottom out. I added GFO to
My carbon reactor, did my weekly 15% water change, and tested again today. I read 2.3!!!!! This is measured with a Hanna Low Range checker (not the better ULR). Is it possible my checkers malfunctioning? None of my corals, including my acros, seem worse for wear which seems impossible at a ppm of 2.3

Parameters
DKh=7.5 (apparently my kalk doser hose fell off so it didn’t dose for a day and a half. Currently fixing that slowly because I usually run 9 dKh)

Salinity 1.026

Nitrate=10.2 ppm

Calcium=436

Magnesium=1450

Temp=77.5-78

Rowboman · Feb 16, 2023

Rowboman said:
So last night I did my weekly phosphate test and got a reading of 0.5. This is over 3 times the highest reading I’ve ever had on this tank!! I normally run under 0.1 and actually have to dose phosphates and nitrates occasionally because they tend to bottom out. I added GFO to
My carbon reactor, did my weekly 15% water change, and tested again today. I read 2.3!!!!! This is measured with a Hanna Low Range checker (not the better ULR). Is it possible my checkers malfunctioning? None of my corals, including my acros, seem worse for wear which seems impossible at a ppm of 2.3

Parameters
DKh=7.5 (apparently my kalk doser hose fell off so it didn’t dose for a day and a half. Currently fixing that slowly because I usually run 9 dKh)

Salinity 1.026

Nitrate=10.2 ppm

Calcium=436

Magnesium=1450

Temp=77.5-78

Update

Fixed the kalk doser and got my Ph back up to 8.3 and 9 dKh. Phosphates dropped down to 0.14 within a day. Apparently it was caused by the sudden loss of kalkwasser in the tank ‍

Placenta89 · Feb 21, 2023

I got the same issue , 0.34 po4 tested this morning. I'm going through so much rowaphos and large water changes I can't seem to get it below 0.22. Did a couple 80% w/c and it reset a diatom bloom and then phosphate keeps going up and up. Highest its gone so far is 0.5. Doing 33% water changes weekly now. I'm assuming the rock and sand have a ton of leeching and hope one day it will level out.. So far no coral stress and everything is happy for the time. Skimmer running 24/7 and chaeto chamber lights on 20 hours a day. Got nO3 down to 5ppm as it was almost at 25 last month. Thank God that guy posted those links because it calmed me down.

Garf · Feb 21, 2023

Placenta89 said:
I got the same issue , 0.34 po4 tested this morning. I'm going through so much rowaphos and large water changes I can't seem to get it below 0.22. Did a couple 80% w/c and it reset a diatom bloom and then phosphate keeps going up and up. Highest its gone so far is 0.5. Doing 33% water changes weekly now. I'm assuming the rock and sand have a ton of leeching and hope one day it will level out.. So far no coral stress and everything is happy for the time. Skimmer running 24/7 and chaeto chamber lights on 20 hours a day. Got nO3 down to 5ppm as it was almost at 25 last month. Thank God that guy posted those links because it calmed me down.

This is a good vid;

Cthulukelele · Feb 21, 2023

It's crazy thinking about the delicate balancing acts in our tank with so much phosphate bound up in rock and sand

Rowboman · Feb 21, 2023

Placenta89 said:
I got the same issue , 0.34 po4 tested this morning. I'm going through so much rowaphos and large water changes I can't seem to get it below 0.22. Did a couple 80% w/c and it reset a diatom bloom and then phosphate keeps going up and up. Highest its gone so far is 0.5. Doing 33% water changes weekly now. I'm assuming the rock and sand have a ton of leeching and hope one day it will level out.. So far no coral stress and everything is happy for the time. Skimmer running 24/7 and chaeto chamber lights on 20 hours a day. Got nO3 down to 5ppm as it was almost at 25 last month. Thank God that guy posted those links because it calmed me down.

Out of curiosity, what’s your pH run at?