Phosphate: How much is too much and do you even worry about it?

[revhtree]

Today let's talk about Phosphate! Sounds exciting huh?! We know that zero phosphates are no good but too much and you have an algae problem! So where do you draw the line or do you even measure where the line is?

1. Do you worry about the phosphate levels in your reef tank?

2. What is your target level of phosphates in your tank?

image via @Reefer350Lighting

 

[reefinnewb]

Yes, after having a dino outbreak a few months ago I try to keep my nitrates at 5 and phosphates above .04.

 

[Wiskey]

I have bleached then killed more SPS by trying to keep my Phosphate at 0.03 then I have by letting it run wild. For that reason I no longer shoot for such a low value. I do use a Fuge and I use VERY low flow GFO, but my P04 target is between 0.08 and 0.12,.. provided it's in that range I don't mess with it.

Thank you,
Whiskey

 

[Quietman]

Keep it measurable but <.20...when it creeps up to that, I add a bit of lanthanum chloride to drop it back to <.05.

 

[Rocketfish]

I am currently running a red sea recipe in a nano tank with zero phosphates with regular dosing of NoPox to bring out the color a bit. I have to say it is working well for sps, hammers, trachy, and zoas, but the short tentacle Goni seems very unhappy!

I do have to feed AB+ at higher levels, and my KH consumption is rather elevated but all considered it's looking pretty good.

 

[Luciferene]

Yes and no. I think once the tank "matured" I don't care about the Phosphate levels but in newer systems it's a good proxy to tell me if there will be algae or water quality issues.

Either way though, I'm not looking for a value but a trend of sudden changes. I don't believe the Phosphate test kits we have in the hobby has the accuracy to properly distinguish from "0.02 to 0.03" for me to draw a conclusion.

In my main display tank, the levels have been from 0.21 to 0.08 since I started measuring it from a few months back. I used to feed corals quite heavily, so just not feeding as often dropped the Phosphate levels over the course of month or so. I haven't seen any change in algae or coral conditions during the changes which are what I look for.

I have 3 new systems since beginning of the year and they hover from 0.01 to 0.07.

 

[elorablue]

Im trying to keep mine between 0.03 and 0.15. Anything in that range I'll be happy, but mine is a new (3 month) 20g tank and still working on stability issues.

 

[NowGlazeIT]

Today let's talk about Phosphate! Sounds exciting huh?! We know that zero phosphates are no good but too much and you have an algae problem! So where do you draw the line or do you even measure where the line is?

1. Do you worry about the phosphate levels in your reef tank?

2. What is your target level of phosphates in your tank?

image via @Reefer350Lighting

CANT do zero I’ve tried. But anything under .1 and my corals are happy. I’m not chasing numbers really,just trying not swing around

 

[Tundra Cuttle]

I do worry about it, for a few reasons. First I have macroalgae that needs Phosphate to stay healthy. Second if phosphate is too high without enough competition hair algae will take over, the problem with the hair algae is that it will move in and proliferate, absorbing phosphate down to the point where it will strip the water of phosphate entirely which will kill your corals and itself.

My aim is below .5 because I'm low on snails but I have found if you have an abundance of snails and starting with a clean slate you don't really have to worry about it. Usually my phosphate test is visual and I want to see if I get algae growth on the glass within 24hrs if I don't see any I know I need to add a little because my macroalgae is stopping other algae from proliferating. If I don't add phosphate once I notice no film algae growth my macroalgae will start to die quickly.

 

[Scorpius]

I like to stay around .10ppm

 

[Azedenkae]

2. My target level for phosphates is 0, because I feed a lot so I know it's not a matter of keeping it slightly above 0 to know for sure there's enough nutrients for corals.

1. I don't worry about it, because I have a diversity of algae growing to soak up excess nutrients from my heavy feedings.

 

[Panama Brown]

I average about .08 but my target is between .04 to .12

 

[ScottB]

I am with @Quietman and @Luciferene both.

New systems I keep managed a bit lower like .05 to .1

Once the system is mature 2-3 years, I prefer .1 ish. When it creeps toward .2 or so, I knock it back with lanthanum chloride. I find it much easier to dial & control than GFO.

Hanna is really the only reliable measuring tool. But you have to keep the cuvettes absolutely spotless.

 

[Tracy in Tampa]

I only worry about it when I see GHA. I’ve learned that stability is better than chasing numbers.

 

[Ljshelby]

Phosphates are a tuff one in my year and a half tank, its a task to keep anything above 0 even when dosing phosphorus. One day it will be .028 and at the end of the day a big fat 0 lol this is where i stopped chasing numbers and would hope everything works itself out! But if anyone has an idea on this please feel free to chime in

 

[Rocketfish]

I do worry about it, for a few reasons. First I have macroalgae that needs Phosphate to stay healthy. Second if phosphate is too high without enough competition hair algae will take over, the problem with the hair algae is that it will move in and proliferate, absorbing phosphate down to the point where it will strip the water of phosphate entirely which will kill your corals and itself.

My aim is below .5 because I'm low on snails but I have found if you have an abundance of snails and starting with a clean slate you don't really have to worry about it. Usually my phosphate test is visual and I want to see if I get algae growth on the glass within 24hrs if I don't see any I know I need to add a little because my macroalgae is stopping other algae from proliferating. If I don't add phosphate once I notice no film algae growth my macroalgae will start to die quickly.

Yeah, I don't have a refugium in the nano tank, and when I went to zero phosphate I had to put the dragon's breath algae in a different tank!

 

[Tundra Cuttle]

Phosphates are a tuff one in my year and a half tank, its a task to keep anything above 0 even when dosing phosphorus. One day it will be .028 and at the end of the day a big fat 0 lol this is where i stopped chasing numbers and would hope everything works itself out! But if anyone has an idea on this please feel free to chime in

If you have fish that you feed daily I'm sure it will work itself out. If you have no fish then it will not come up from zero and many corals will be unhappy with it. But I think I'm the only person keeping corals without fish so, you're probably fine.

 

[Gtinnel]

I guess I do worry about it because I do test for it about once a week. I am happy with anything above 0. Usually my tanks stays around .05 and never really goes any higher so it is not something I have ever needed to correct in any way.

 

[ScottB]

Phosphates are a tuff one in my year and a half tank, its a task to keep anything above 0 even when dosing phosphorus. One day it will be .028 and at the end of the day a big fat 0 lol this is where i stopped chasing numbers and would hope everything works itself out! But if anyone has an idea on this please feel free to chime in

Eventually your rock and sand will bind up enough phosphate to keep enough available in the water column. It will gradually leach PO4 back when the water is "cleaner" relative to the rock.

Dosing phosphorus can accelerate that process, but you might be surprised how much of the additive will bind. I went through 2 liters of the stuff over a few months. Have not had to dose a drop since then. That was years ago.

 

[RDaber]

In my old tanks I never even tested for phosphate. After returning to the hobby after 15 years I try to keep it between 0.03 and 0.12 and usually run at 0.07.