Phosphate Plateauing at .19-.22ppm

Bhor217 · Dec 7, 2020

Hey all, just have a question regarding my Phospate levels.

I installed a GFO about a month ago, when my phosphate levels read at .71, since then, I have brought the numbers down to .19-.22 but it seems that they have plateaued there.

I am running a GFO, a biopellet reactor, protein skimmer, and use a 5 stage RODI, as well as do 20% WC on my 150G system 2x/month. See updated tank parameters from tests today:

Alk: 8.6
Mag: 1320
Ca: 440
NO3: 2
Phosphate: .19

I have no issues with nuisance algae, but I know my phosphate levels are not in the desired mix reef range. Should I change out the media in my GFO, or perhaps add more? I currently have about 3 fingers worth of media in the reactor.

Since my Phosphate numbers have plateaued and only change from .19-.22 since installing the GFO, would using some sort of one time treatment to bring my levels down to the 2-5 range be sufficient?

I feed my fish reef frenzy daily (Midas Blenny, 2 Oceleris Clowns, Mandirin and Fairy wrasse) and my snowflake eel table shrimp 1 time a week. I dose 35ML of Red Sea Aminos 1x a week on Sundays.

Any guidance you can give is appreciated!

xxkenny90xx · Dec 7, 2020

Lanthanum Chloride is the way to go for reducing Po4 quickly. That being said why do you want to reduce it? Are your corals suffering?

Bhor217 · Dec 7, 2020

xxkenny90xx said:
Lanthanum Chloride is the way to go for reducing Po4 quickly. That being said why do you want to reduce it? Are your corals suffering?

no my corals are not suffering, but I know that .19-.23 is on the high range for a mixed reef, so rather than just ignore it, I figured I would ask people’s opinion.

do you feel successful reefs can run at .19-23?

laverda · Dec 7, 2020

I would not reduce it much.

xxkenny90xx · Dec 8, 2020

Bhor217 said:
no my corals are not suffering, but I know that .19-.23 is on the high range for a mixed reef, so rather than just ignore it, I figured I would ask people’s opinion.

do you feel successful reefs can run at .19-23?

Successful reefs can be ran with Po4 above .8

Mine hangs out between
.1 and .2 and I never have any algae issues or anything

Potatohead · Dec 8, 2020

I would say .15 - .2 is ideal for a mixed reef

. Even higher is no problem if no algae problems.

dwest · Dec 8, 2020

What test kit are you using? Have you tried another test kit or double checked it somehow? I also agree that your current levels are fine as long as your tank is doing well.

BizarroKeyLargo · Jan 10, 2021

Wanted to bump this thread to ask the question from the other side. I got my PO4 way out of wack carbon dosing so I phased off of that and hair algae went crazy. Testing 2-3ppm NO3 and .1-.2 PO4 with relentless hair algae. Corals other than a tort of some sort and a mariculture acro are happy and extended but algae is stifling encrusting growth. I've been dosing vibrant for 4 weeks and still not much progress so after 3 more weeks I plan to try reef-flux, just worried about levels afterwards.

Dan_P · Jan 10, 2021

Bhor217 said:
Hey all, just have a question regarding my Phospate levels.

I installed a GFO about a month ago, when my phosphate levels read at .71, since then, I have brought the numbers down to .19-.22 but it seems that they have plateaued there.

I am running a GFO, a biopellet reactor, protein skimmer, and use a 5 stage RODI, as well as do 20% WC on my 150G system 2x/month. See updated tank parameters from tests today:

Alk: 8.6
Mag: 1320
Ca: 440
NO3: 2
Phosphate: .19

I have no issues with nuisance algae, but I know my phosphate levels are not in the desired mix reef range. Should I change out the media in my GFO, or perhaps add more? I currently have about 3 fingers worth of media in the reactor.

Since my Phosphate numbers have plateaued and only change from .19-.22 since installing the GFO, would using some sort of one time treatment to bring my levels down to the 2-5 range be sufficient?

I feed my fish reef frenzy daily (Midas Blenny, 2 Oceleris Clowns, Mandirin and Fairy wrasse) and my snowflake eel table shrimp 1 time a week. I dose 35ML of Red Sea Aminos 1x a week on Sundays.

Any guidance you can give is appreciated!

It seems that your GFO might be exhausted. If true, you could remove the old medium and replace it with just a little fresh GFO to nudge the PO4 down.

Only certain coral don’t do well at higher PO4 levels. If you feel your system is thriving, there is no need to go lower. If your system is doing well but you are uneasy about the PO4, slowly nudge it down further. You might find that your system’s PO4 slowly creeps upward over time. You might want to nudge it downward every so often.