How much PO4 is too much

[dmw913]

Seriously, @Randy Holmes-Farley , you are basically the BEST! You give so freely of your time and knowledge! Please know how much it is appreciated!

Best,
Denise

 

[Randy Holmes-Farley Verified Community Expert]

I agree in that P04 should be 0.03 or lower which is where I try to keep my tank via Red Sea NOPOX dosing. A few days ago I started noticing my acro polyps not extending. Nitrates were below 0.25 but my P04 was at 0.17. Noticed a buildup of detritus in my sump and did a good cleaning and water change. Hoping this will bring my P04 back down.

I expect NOPOX will fail to control the phosphate. There's not enough nitrate present to allow you to bring down phosphate that much.

 

[Randy Holmes-Farley Verified Community Expert]

Seriously, @Randy Holmes-Farley , you are basically the BEST! You give so freely of your time and knowledge! Please know how much it is appreciated!

Best,
Denise

Thanks very much!

Happy reefing.

 

[PSXerholic]

So looking at the chart above with reference to the Redfield ratio my tank has a steady No3 of 2 and a Po4 of 0.03. This would seem to say that my Po4 is too low? Should I increase it or am I just chasing rabbits down holes?

@Joe Batt , check this thread out since it goes into the same subject direction, talking about the imbalance of nutrients and how to likely resolve it ;-)

https://www.reef2reef.com/threads/nitrate-phosphate-imbalance.310942/page-3

-Andre

 

[Randy Holmes-Farley Verified Community Expert]

So looking at the chart above with reference to the Redfield ratio my tank has a steady No3 of 2 and a Po4 of 0.03. This would seem to say that my Po4 is too low? Should I increase it or am I just chasing rabbits down holes?

No. The Redfield ratio has ZERO to do with concentrations in the water. It is the ratio of N and P (and some other things) taken up by phytoplankton (and is similar in many organisms). It is not a ratio to be strived for in the tank.

 

[Zagreus]

I notice the algae on the glass is brown as opposed to green.

I dose NoPox and my No3 is a steady 2 and Po4 0.03. I also notice my corals are slow to grow compared to other peoples tanks and possibly with less colour.

I dose 24/7. Ca, Kh and Mg. My Ca is steady at 430 and Kh steady at 9.2dKh.

I use a RoDi system and check it regularly TDI is at 0.

My flow is good, around 35x volume and lighting is via Hydra 52 HD plus supplemental 2xT5. Photo-period is around 10 hours a day with the PAR at the top around 250 and at the bottom 175.

Weekly cleaning, and vacuuming the sand. Bi weekly 10% water changes.

Any tips as to where I might be going wrong? I put a lot of effort into my tank and have done for 2 years with not great results. The most annoying thing is I know friends who seem to do nothing to their tanks and have amazing growth and colour even though their levels are off when I have tested their water.

I have the same problem and similar setup. I was told I maybe starving my corals of no3 po4 by using too much nopox and gfo and or a new tank issue for using exclusive reefsaver dead rock.

 

[Randy Holmes-Farley Verified Community Expert]

I have the same problem and similar setup. I was told I maybe starving my corals of no3 po4 by using too much nopox and gfo and or a new tank issue for using exclusive reefsaver dead rock.

Have you measured nitrate and phosphate?

 

[Zagreus]

Have you measured nitrate and phosphate?

Well thank you so much Randy for replying yes I have a link of sent to you shortly my P04 was around .04

Have you measured nitrate and phosphate?

THANK YOU Randy so much for commenting. I have been using NoPox consistently and about a month ago added GFO to help keep my phosphates down concurently. My No3 is less than 1 ppm and my P04 is .04-.08. The following threat provides alot of detail and if you have time provides all my numbers and details if you have a moment.

https://www.reef2reef.com/threads/experienced-acropora-sps-keepers-1-year-help-needed.327336/

I really hope its not just some new tank syndrome with using dead rock and having a 7 month old tank and its something I can fix. Per your feedback and the advice I was considering cutting the NoPox to 1-2ml from 3ml to keep my nitrates below 10ppm and half my GFO to keep it less than P04 .08.

Anyway thank you in advance. Amazing to have access to a Harvard Chemist.