How much phosphate is too much

Neoalchemist · Apr 13, 2019

howaboutme said:
Read up about redfield ratio. Basically, if you are nitrate limited, you may have trouble lowering your PO4. I am in the same boat so I am dosing KNO3 to bring up my NO3 to at least 2ppm. I am just beginning this process so we'll see what happens.

Also, do you have algae of any kind? If so, your algae will consume PO4 faster so you will get misleading readings anyways. Visually, by seeing if you have algae, is the best way initially to know if you have too high of PO4. Once your algae goes away, a tester will be more accurate.

I wish I could "like" this more than once. Without a nutrient balance tanks usually have one problem After another.

User1 · Apr 13, 2019

What dry rock did you use? Some rock leach moer than others reqgarless if you used bleach or acid. I have 150 lbs of dry pukani that I used last year and I believe that is my source of high phosphates. Something to consider that may require using a couple different methods of reducing it. I believe the rock has a lot in there and it will take a while to remove completely so I'm dosing NoPox.

I've lowered it previously only to have it come back so believe it has a reserve and I'll need to continue to dose.

cjb428 · Apr 14, 2019

Bastray said:
I would just do whatever is easiest for you. If converting it for your use makes it easier than do that. If I had that checker I would just use ppb personally so I don't have to convert. LoL. It's the same number at the end of the day.

Yeah, that’s what I figured, I just wasn’t sure what the acceptable levels were since everyone seems to use ppm. I bought a master reef kit! This is going to be my first reef tank. It’s been running 6 weeks right now and I just got my test kit. Nothing in the tank yet but I added 2 small clown fish a week ago. My phosphorus level is 44 ppb which from what I read is high. Everything is see says a reef should be below 30 ppb but when I look at the posts here everyone is talking numbers of 0.01 and 0.1 ppm which tells me that I have some work to do. I tested my RO water and it’s at 13 ppb, then I tested my tap and it’s at 94 ppb so I have to assume my RO unit is doing something.

cjb428 · Apr 14, 2019

Bastray said:
I would just do whatever is easiest for you. If converting it for your use makes it easier than do that. If I had that checker I would just use ppb personally so I don't have to convert. LoL. It's the same number at the end of the day.

So what am I looking to achieve? 10 ppb?

Neoalchemist · Apr 14, 2019

This is the Hanna conversion chart I use

Neoalchemist · Apr 14, 2019

I shoot for .06 ppm phosphate or 20 ppb phosphorus because I don't like being that close to zero since I've experienced dinoflagellates due to allowing my nutrients to bottom out.

cjb428 · Apr 14, 2019

Neoalchemist said:
This is the Hanna conversion chart I use

Thank you, appreciate it

cjb428 · Apr 14, 2019

Neoalchemist said:
I shoot for .06 ppm phosphate or 20 ppb phosphorus because I don't like being that close to zero since I've experienced dinoflagellates due to allowing my nutrients to bottom out.

That helps a lot. I’ve seen a lot of videos stating you want some level of phosphorus

DEWreefing · Jun 29, 2019

I have always kept my phosphates around 1 to .50

lapin · Jun 29, 2019

Mine vary. After a good cloudy coral feeding on Sunday night. They can go from a normal 23ppb (.07) to 60ppb (.18) by Monday morning.

User1 · Jun 30, 2019

lapin said:
Mine vary. After a good cloudy coral feeding on Sunday night. They can go from a normal 23ppb (.07) to 60ppb (.18) by Monday morning.

I've never tied it to feedings but I've also seen mine do similar to what you noted above over 30 days. I always thought it was caused by the rock I used, dry Pukani. I've measured with a reading of .08 ppm using Hanna's checker and a ATI ICP test from the same day/water than 30 days later another test using the Hanna checker showed it .18. Not sure if .10 in 30 days means anything but that is what is happening in my tank.

Neoalchemist · Jun 30, 2019

saf1 said:
What dry rock did you use? Some rock leach moer than others reqgarless if you used bleach or acid. I have 150 lbs of dry pukani that I used last year and I believe that is my source of high phosphates. Something to consider that may require using a couple different methods of reducing it. I believe the rock has a lot in there and it will take a while to remove completely so I'm dosing NoPox.

I've lowered it previously only to have it come back so believe it has a reserve and I'll need to continue to dose.

Keep an eye though. I had a similar situation with a previous tank that had some terrestrial tufa rock as a base. I ran moderate gfo for years. It was routine. Then in year 6 of the tanks life I unknowingly at some point exhausted to po4 reserves. First came the coral lightening, But growth was exeptional. Then sudden rtn, lost a lot of colonies that were previously growing out of the water.
Back then there was no way to test po4 below .1 so you couldn't tell the difference between low po4 and no po4. IMO, the Hanna ulr phosphate and ulr phosphorus checkers are just as important as a good alk test.

User1 · Jun 30, 2019

Neoalchemist said:
Keep an eye though. I had a similar situation with a previous tank that had some terrestrial tufa rock as a base. I ran moderate gfo for years. It was routine. Then in year 6 of the tanks life I unknowingly at some point exhausted to po4 reserves. First came the coral lightening, But growth was exeptional. Then sudden rtn, lost a lot of colonies that were previously growing out of the water.
Back then there was no way to test po4 below .1 so you couldn't tell the difference between low po4 and no po4. IMO, the Hanna ulr phosphate and ulr phosphorus checkers are just as important as a good alk test.

Thanks!

Ebelair · Mar 31, 2021

Love the Tang said:
We'll come to find out the API test kit could not calculate my phosphate I got a test kit from Red Sea and tested .12 . also is the Red Sea kit any good? I saw you all recommend salifert and other brands how does the Red Sea compare.

IMO forget the Red Sea test kit!!! I was getting a consistent 0.08 for months until I got a Hanna Test Kit. It told me my phosphates were 3.7!! Yikes! Took me over a week to get them back under 0.1.

ecip91 · Sep 3, 2022

Ebelair said:
IMO forget the Red Sea test kit!!! I was getting a consistent 0.08 for months until I got a Hanna Test Kit. It told me my phosphates were 3.7!! Yikes! Took me over a week to get them back under 0.1.

I just tested my phosphates this morning and they were around 4 ish. I think I need to drop that down a bit haha. Probably gonna get some GFO

vetteguy53081 · Sep 3, 2022

ecip91 said:
I just tested my phosphates this morning and they were around 4 ish. I think I need to drop that down a bit haha. Probably gonna get some GFO

Yes, high. Safe range .04 - .06