Urgent help needed!!!

[Randy Holmes-Farley Verified Community Expert]

What type of sand?

 

[Genvid]

What type of sand?

CaribSea Special Grade Arag-Alive and 10 kg of live sand from Tampa Bay

 

[Randy Holmes-Farley Verified Community Expert]

Ok, I’m not seeing where the alk is coming from. Either the rock or mud would be a guess, but others have used those without issue. But some rock sources and some sand sources (the mud looks like sand) have seen substantial alk released from them,

Did you see the packaging of the rock to know it was not a different brand? Some folks had problems with an Aquaforest rock product.

 

[Genvid]

Ok, I’m not seeing where the alk is coming from. Either the rock or mud would be a guess, but others have used those without issue. But some rock sources and some sand sources (the mud looks like sand) have seen substantial alk released from them,

Did you see the packaging of the rock to know it was not a different brand? Some folks had problems with an Aquaforest rock product.

For the previous three years, there hadn't been any issues with this rock. I had completely forgotten that, after every water change, I used to add BIOReef-Snow from Modern Reef.

 

[Randy Holmes-Farley Verified Community Expert]

Ok, so not the rock. Are you still adding the snow? Any suspended calcium carbonate particles will give false high alk and calcium readings because they will dissolve in the test.

 

[Genvid]

Ok, so not the rock. Are you still adding the snow? Any suspended calcium carbonate particles will give false high alk and calcium readings because they will dissolve in the test.

I'll be doing a water change today and will refrain from adding Coral Snow.

 

[jackalcodon]

Hi Reefers,

My tanks is one year old now. I setup started in July 2025. My parameters are stable for Alk, PH, Ca. However, my Nitrates constantly is 20- 25ppm. My PO4 used to be 0.06 - 0.14ppm in Jan and March 2026. And goes up from April until now, and reach 0.44ppm. I currently running Phosguard, but seem not able to to get it down much. My latest test today is N: 25ppm, P: 0.34ppm.
I used to dose vinegar in the beginning after cycle (when I fight the urgly stage). Should I started to dose vinegar again, and if I need to keep dosing that all the time?
My parameters are (tested today)
Temp: 27o C
Salt: 1.025 sg
Alk: 8.6 ppm
Ca: 430 ppm
Mg: I haven’t tested for a long time. Last number is 1320ppm in Sept 2025
Ph: 8.4
No3: 25ppm
Po4: 0.35ppm
I currently do WC every 2 weeks. Before was 1/week. I feed once per day (pellets) and small amount of nori.

I though my No3 is 25ppm which is fine as is stable. However, I would love to solve the Po4 issue as I have some Sps in the tanks. Thank you.

Below is my tank photo.

 

[Randy Holmes-Farley Verified Community Expert]

Hi Reefers,

My tanks is one year old now. I setup started in July 2025. My parameters are stable for Alk, PH, Ca. However, my Nitrates constantly is 20- 25ppm. My PO4 used to be 0.06 - 0.14ppm in Jan and March 2026. And goes up from April until now, and reach 0.44ppm. I currently running Phosguard, but seem not able to to get it down much. My latest test today is N: 25ppm, P: 0.34ppm.
I used to dose vinegar in the beginning after cycle (when I fight the urgly stage). Should I started to dose vinegar again, and if I need to keep dosing that all the time?
My parameters are (tested today)
Temp: 27o C
Salt: 1.025 sg
Alk: 8.6 ppm
Ca: 430 ppm
Mg: I haven’t tested for a long time. Last number is 1320ppm in Sept 2025
Ph: 8.4
No3: 25ppm
Po4: 0.35ppm
I currently do WC every 2 weeks. Before was 1/week. I feed once per day (pellets) and small amount of nori.

I though my No3 is 25ppm which is fine as is stable. However, I would love to solve the Po4 issue as I have some Sps in the tanks. Thank you.

Below is my tank photo.

There are numerous ways to lower phosphate, but I'd be wary of doing so in a tank that looks to be doing fine.

 

[jackalcodon]

Hi Reefers,

My tanks is one year old now. I setup started in July 2025. My parameters are stable for Alk, PH, Ca. However, my Nitrates constantly is 20- 25ppm. My PO4 used to be 0.06 - 0.14ppm in Jan and March 2026. And goes up from April until now, and reach 0.44ppm. I currently running Phosguard, but seem not able to to get it down much. My latest test today is N: 25ppm, P: 0.34ppm.
I used to dose vinegar in the beginning after cycle (when I fight the urgly stage). Should I started to dose vinegar again, and if I need to keep dosing that all the time?
My parameters are (tested today)
Temp: 27o C
Salt: 1.025 sg
Alk: 8.6 ppm
Ca: 430 ppm
Mg: I haven’t tested for a long time. Last number is 1320ppm in Sept 2025
Ph: 8.4
No3: 25ppm
Po4: 0.35ppm
I currently do WC every 2 weeks. Before was 1/week. I feed once per day (pellets) and small amount of nori.

I though my No3 is 25ppm which is fine as is stable. However, I would love to solve the Po4 issue as I have some Sps in the tanks. Thank you.

Below is my tank photo.

There are numerous ways to lower phosphate, but I'd be wary of doing so in a tank that looks to be doing fine.

Should I worried with my current No3 and Po4? I am not sure if my tank doing fine. The soft and low look fine, but some sps look pale.

 

[Randy Holmes-Farley Verified Community Expert]

Should I worried with my current No3 and Po4? I am not sure if my tank doing fine. The soft and low look fine, but some sps look pale.

I would read this to see tanks with higher levels than yours which are perfectly fine.

https://www.reef2reef.com/ams/randy’s-thoughts-on-nutrient-target-ranges.1087/

 

[Alexander1312]

Hi Reefers,

My tanks is one year old now. I setup started in July 2025. My parameters are stable for Alk, PH, Ca. However, my Nitrates constantly is 20- 25ppm. My PO4 used to be 0.06 - 0.14ppm in Jan and March 2026. And goes up from April until now, and reach 0.44ppm. I currently running Phosguard, but seem not able to to get it down much. My latest test today is N: 25ppm, P: 0.34ppm.
I used to dose vinegar in the beginning after cycle (when I fight the urgly stage). Should I started to dose vinegar again, and if I need to keep dosing that all the time?
My parameters are (tested today)
Temp: 27o C
Salt: 1.025 sg
Alk: 8.6 ppm
Ca: 430 ppm
Mg: I haven’t tested for a long time. Last number is 1320ppm in Sept 2025
Ph: 8.4
No3: 25ppm
Po4: 0.35ppm
I currently do WC every 2 weeks. Before was 1/week. I feed once per day (pellets) and small amount of nori.

I though my No3 is 25ppm which is fine as is stable. However, I would love to solve the Po4 issue as I have some Sps in the tanks. Thank you.

Below is my tank photo.

Great looking tank. Seems like many of your corals like your nutrient levels.

Zooming in, this might be different, but not visible on this picture. You will know you tank’s weak spots better.

To answer your questions: If you want to lower your PO4, you can do this with GFO in a slow moving media reactor. The best and safest way in my opinion.

Use the lowest amount recommended in the beginning. No abrupt reduction. Some think that e.g. reducing 0.35 to 0.15 or lower should be done over a years time (!), not faster, or rather the same time it took to increase them.

What you will notice though is that PO4 might not still come down for a while. You will replace the media and feel nothing is happening, until a few weeks (or longer) into the process, and then PO4 will decline suddenly (but hopefully not drastically!).

The reason is that the rocks could have absorbed this over the past 12 months and continue to release PO4 into the water when the media is removing it from the water column, seemingly not allowing the levels to drop (net).

Two other comments:

1. Your feeding amount seems very low and yet you still see elevated nutrients. While I am normally in the unpopular camp ‘feed less’, yours is even lower than what I would consider appropriate with the fish I am seeing. So, increasing your feeding while actively reducing your PO4 could be a good idea. And you might not see an increase in NO3 if your skimmer is adequate.

2. Your SPS might still be pale after reducing PO4. In fact, this is very likely. Running optimal conditions for SPS without ICP is not a skill that the majority of reefers possess. Therefore, I would run an ICP, either from Oceamo or Fauna Marin.

 

[jackalcodon]

Hi Reefers,

My tanks is one year old now. I setup started in July 2025. My parameters are stable for Alk, PH, Ca. However, my Nitrates constantly is 20- 25ppm. My PO4 used to be 0.06 - 0.14ppm in Jan and March 2026. And goes up from April until now, and reach 0.44ppm. I currently running Phosguard, but seem not able to to get it down much. My latest test today is N: 25ppm, P: 0.34ppm.
I used to dose vinegar in the beginning after cycle (when I fight the urgly stage). Should I started to dose vinegar again, and if I need to keep dosing that all the time?
My parameters are (tested today)
Temp: 27o C
Salt: 1.025 sg
Alk: 8.6 ppm
Ca: 430 ppm
Mg: I haven’t tested for a long time. Last number is 1320ppm in Sept 2025
Ph: 8.4
No3: 25ppm
Po4: 0.35ppm
I currently do WC every 2 weeks. Before was 1/week. I feed once per day (pellets) and small amount of nori.

I though my No3 is 25ppm which is fine as is stable. However, I would love to solve the Po4 issue as I have some Sps in the tanks. Thank you.

Below is my tank photo.

Great looking tank. Seems like many of your corals like your nutrient levels.

Zooming in, this might be different, but not visible on this picture. You will know you tank’s weak spots better.

To answer your questions: If you want to lower your PO4, you can do this with GFO in a slow moving media reactor. The best and safest way in my opinion.

Use the lowest amount recommended in the beginning. No abrupt reduction. Some think that e.g. reducing 0.35 to 0.15 or lower should be done over a years time (!), not faster, or rather the same time it took to increase them.

What you will notice though is that PO4 might not still come down for a while. You will replace the media and feel nothing is happening, until a few weeks (or longer) into the process, and then PO4 will decline suddenly (but hopefully not drastically!).

The reason is that the rocks could have absorbed this over the past 12 months and continue to release PO4 into the water when the media is removing it from the water column, seemingly not allowing the levels to drop (net).

Two other comments:

1. Your feeding amount seems very low and yet you still see elevated nutrients. While I am normally in the unpopular camp ‘feed less’, yours is even lower than what I would consider appropriate with the fish I am seeing. So, increasing your feeding while actively reducing your PO4 could be a good idea. And you might not see an increase in NO3 if your skimmer is adequate.

2. Your SPS might still be pale after reducing PO4. In fact, this is very likely. Running optimal conditions for SPS without ICP is not a skill that the majority of reefers possess. Therefore, I would run an ICP, either from Oceamo or Fauna Marin.

I have been running reactor with Phosguard for a months now. Last change GFO was 23rd July (85gr) and Po4 measured 0.34ppm at 31/7, and po4 measured on 18/7 is 0.44ppm.

I can see my red digi growth with nice colors in April. This pic taken in 24/4, at that time my po4 is 0.25ppm.

My current GFO setup. I think I will dose vinegar every day, but with question do I need to add microbiology with bacter 7 every day? I currently add after wc every 2 week, following instructions