High Phosphates - Let's lower it!

Daniel91 · Jul 11, 2019

Well, I was testing tonight and found my phosphates at 0.16 using the Hanna ULR ppm checker for both my tanks.

Threw me off a little as all the corals are doing great and I did a 20% water change of both tanks (13gal and 10gal) a couple of days ago.

My RO/DI water shows 0 TDS - carbon/sediment is due for a change but could that really it?

I always watch my feeding and I do not stock heavy in either tank - what could be contributing to this number?

Seeing as corals are happy, I am not in a rush to lower it but I would like to get it down to the ideal level of around 0.05 ppm.

ReefinItReal88 · Jul 12, 2019

Daniel91 said:
Well, I was testing tonight and found my phosphates at 0.16 using the Hanna ULR ppm checker for both my tanks.

Threw me off a little as all the corals are doing great and I did a 20% water change of both tanks (13gal and 10gal) a couple of days ago.

My RO/DI water shows 0 TDS - carbon/sediment is due for a change but could that really it?

I always watch my feeding and I do not stock heavy in either tank - what could be contributing to this number?

Seeing as corals are happy, I am not in a rush to lower it but I would like to get it down to the ideal level of around 0.05 ppm.

I maintain a balance with gfo and NoPox

o2manyfish · Jul 12, 2019

Unless using a system like Zeovit and looking supplementing ultra low nutrients with additives, having a low Phos reading is not ideal.

In the wild corals have a ton of microfauna to feed on. In our tanks - no matter who amazing you think your pod population, it's nothing compared to what mother nature has.

So in your tank your corals need food - and that is phosphates - nutrients in the water column for the corals to consume.

You want as much phosphates as possible for your filtration capabilities. And there isn't a set number. My tank hasn't been under 1.4 for the past 5 years and a year ago the phosphates were 2.4 for about 4 months. Many public aquariums are running reef tanks with phosphate values higher than that.

Targeting a number without a real reason is of no value in this hobby. You want to maintain stability with a range that suits your system.

If your corals are looking good at the phosphate levels you have now... Then don't mess with what's working.

Dave B

Hemmdog · Jul 12, 2019

How old is your tank? Dry rock?

SPR1968 · Jul 12, 2019

The following article should answer your question I think, and as you will see to avoid potential issues, a good target is very low at around 0.o3ppm.

http://reefkeeping.com/issues/2006-09/rhf/

I personally keep mine locked down with Rhowaphos in a reactor. If you do lower it I would just do it slowly as your corals may have adapted to the higher levels

Daniel91 · Jul 12, 2019

Thanks for the feedback all.

Again, it’s not critical as everything seems happy and I don’t want to chase a specific lower number - I just want to slowly decrease it.

I’ll do an extra waterchange this week

Thanks!

nereefpat · Jul 12, 2019

Water changes don't do much for phosphates. They are bound in equilibrium between the water and sand/rock.

As you said, everything is fine, so don't worry about them too much.

What are your nitrates? @Hemmdog 's questions are relevant too, imo.

Daniel91 · Jul 12, 2019

Hemmdog said:
How old is your tank? Dry rock?

A year and yes, BRS dry rock.

nereefpat said:
What are your nitrates? @Hemmdog 's questions are relevant too, imo.

Between 5-10.

Thanks!

nereefpat · Jul 12, 2019

A year old tank, started with dry rock (probably leaching a bit of P). A little bit of phosphate, and a little bit of nitrate. I bet those numbers will come down on their own as the tank matures.

jim_fitz · Jul 12, 2019

I think my eyes are my best test kit
My levels are very similar

But no one has told my corals

link81 · Jul 12, 2019

.16 isnt terrible at all. many people (myself included) shoot for 0.1ppm po4 and about 10-20 ppm no3.
so you're very close to what many of us would consider ideal.

jim_fitz · Jul 12, 2019

i have searched high and low for the original data that stated 0.03

if anyone knows it
please let me know

i kinda suspect someone might have tested some water on a reef and thast stuck and has been quoted ever since

or dare i suggest it was suggested by a manufacturer ???

(quite happy to be proven wrong on this
but i work in sewage filtration
and am qualified in process engineering from Delft University )

SPR1968 · Jul 13, 2019

jim_fitz said:
i have searched high and low for the original data that stated 0.03

if anyone knows it
please let me know

i kinda suspect someone might have tested some water on a reef and thast stuck and has been quoted ever since

or dare i suggest it was suggested by a manufacturer ???

(quite happy to be proven wrong on this
but i work in sewage filtration
and am qualified in process engineering from Delft University )