Target phosphate levels

[phinatic]

I have seen a lot of differing information on phosphate levels. In the past, I have not really tested it much and just made sure I kept my algae in check. I have always assumed that keeping fish in the reef would make sure the corals get enough phosphate via leftover food. The levels in my new tank go between 0.125 and 0.25 depending on feeding level. The algae isn't an issue and there should be enough for bacteria and coral going forward.

 

However, BRS and a few other sites recommend 0.01-0.03. These levels seem very low to me. I don't really know why they keep them that low as I thought the only real downside to phosphate was algae growth.

 

Purple Helix also claim their coraline spores won't grow out if phosphates are over 0.02

 

Any thoughts?

[SLA10]

These topics can be difficult, yes algae and corals, the algae the corals use to generate the energy they need for sustenance can be affected by phosphate levels, and you definately want them low, when you measure phosphates your really measuring excess in your system, as phosphates utilized by your corals won't be measured.  Just as I never show nitrates in my tests, there is certainly nitrates being generated.  Optimally you try to keep phosphates as low as possible measurement wise which indicates there are phosphates available to your reef system, just not an excessive amount in your overall system.  So the closer to zero but still measurable, is the goal.

[MLS_Reef]

Coming back into reefing and more so reefing on the web and discussions the whole you need phosphates and nitrates is new to me. 15 years ago people were running copious amounts of gfo and sulfur reactors trying to strip everything they possibly could out of the water and achieve 0 scores with their test kits, Now its like balance young grasshopper, you must balance...   

 

I dipped back into the hobby a couple times but did not really read anymore about anything.

 

 

[SLA10]

3 minutes ago, MLS_Reef said:

Coming back into reefing and more so reefing on the web and discussions the whole you need phosphates and nitrates is new to me. 15 years ago people were running copious amounts of gfo and sulfur reactors trying to strip everything they possibly could out of the water and achieve 0 scores with their test kits, Now its like balance young grasshopper, you must balance...   

 

I dipped back into the hobby a couple times but did not really read anymore about anything.

 

 

Yes the hobby has changed tremendously over the years, I can remember just trying to keep nitrates under 20ppm.

 

And the internet almost hurts as much as it helps at times, but there is alot of good info out there and hobbyist pushing the envelope to figure things out, people run systems and corals now that were impossible decades ago.  Successful tank breeding of certain species, corals and fish, it's kind of exciting how much the hobby continues to grow.

[phinatic]

1 hour ago, SLA10 said:

not an excessive amount in your overall system

Thanks. That makes sense. Looking for 0 excess, not 0.

[SLA10]

12 minutes ago, phinatic said:

Thanks. That makes sense. Looking for 0 excess, not 0.

I wouldn't kill myself trying to get .01, my tank runs about .1 there are things you can do to chase that number, chemi blue, reactors, moderating feeding, anything .1 or under I think your doing ok.

[mcarroll]

4 hours ago, phinatic said:

I have seen a lot of differing information on phosphate levels. In the past, I have not really tested it much and just made sure I kept my algae in check. I have always assumed that keeping fish in the reef would make sure the corals get enough phosphate via leftover food.

In a mature tank with good live rock and a moderate-to-heavy fish population, this is likely.

 

Much less-assured in a new tank where nutrients don't get recycled as much (or at all) and where corals, flow, etc aren't necessarily established.

 

4 hours ago, phinatic said:

The levels in my new tank go between 0.125 and 0.25 depending on feeding level. The algae isn't an issue and there should be enough for bacteria and coral going forward.

That's a good range, and that's logical thinking for the most part.  Though CUC is actually the primary factor that keeps algae in check.

 

4 hours ago, phinatic said:

However, BRS and a few other sites recommend 0.01-0.03. These levels seem very low to me. I don't really know why they keep them that low as I thought the only real downside to phosphate was algae growth.

I'm not sure THEY really know why either.

 

If you read up there was plenty of rationale for it....the model was water in the open ocean (eg atoll reefs) where dissolved nutrient levels tend toward 0.00 ppm.

 

Turns out that's only one model of reef, and there's not necessarily a "best" model.  For example there are plenty of high-nutrient reefs and moderate-nutrient reefs out there.

 

4 hours ago, phinatic said:

Purple Helix also claim their coraline spores won't grow out if phosphates are over 0.02

I/someone would have to test that.  It's possible.  That algae's metabolism isn't the same as coral's, so it could be more greatly affected by dissolved PO4.  

 

Or.....they could be parroting stale advice about nutrient levels.  (I haven't read what their take is.....just going off your quote.)

 

0.03 ppm PO4 is sorta the minimum to sustain photosynthesis....at least in a growing system, that's a minimum I recommend keeping.

 

4 hours ago, phinatic said:

Any thoughts?

Usually. 😄