How fast can you drop phosphates

[Wolf89]

My phosphates are waaaaay too high and it has killed almost all of my hard corals. It's about 2 ppm. I have rowaphos on the way. How fast can I drop it with hurting the rest of my corals?

 

[Super Fly]

My phosphates are waaaaay too high and it has killed almost all of my hard corals. It's about 2 ppm. I have rowaphos on the way. How fast can I drop it with hurting the rest of my corals?

According to Phosphate RX instruction, it says not to lower PO4 more than 0.5ppm in a 24 hr period.

 

[Randy Holmes-Farley Verified Community Expert]

I think you'll find it hard to lower it quickly and get it to stay low (since there is also a lot bound to rock and sand ready to come off when you lower it), but go slow to give organisms a chance to alter their phosphate uptake capabilities.

 

[Fishingandreefing]

I think you'll find it hard to lower it quickly and get it to stay low (since there is also a lot bound to rock and sand ready to come off when you lower it), but go slow to give organisms a chance to alter their phosphate uptake capabilities.

Randy is right. I have been fighting high phosphate for almost 6 months. Every time I use LC to lower it and it will rise back up. Always at around .29.

 

[Wolf89]

I think you'll find it hard to lower it quickly and get it to stay low (since there is also a lot bound to rock and sand ready to come off when you lower it), but go slow to give organisms a chance to alter their phosphate uptake capabilities.

How much rowaphos do you recommend? I have a system of about 225 gallons, bare bottom. 2+ ppm of phosphate

 

[Randy Holmes-Farley Verified Community Expert]

How much rowaphos do you recommend? I have a system of about 225 gallons, bare bottom. 2+ ppm of phosphate

Maybe a cup at a time, changed after a few days to a week.

 

[Wolf89]

Maybe a cup at a time, changed after a few days to a week.

Well I only order 250 ml because that was supposed to be able to remove 3ppm if phosphate from 250 gallons. That's more phosphate and water than I have. But it seems you're telling me it not be enough?

 

[Super Fly]

Well I only order 250 ml because that was supposed to be able to remove 3ppm if phosphate from 250 gallons. That's more phosphate and water than I have. But it seems you're telling me it not be enough?

In my 93 cube, to lower PO4 from 0.10 to 0.03 I just use 2-3 tablespoon of Rowaphos. I noticed that when rinsing Rowaphos clean a lot of it goes down the drain or are too fine to use in reactor (i.e. doesn't tumble). A cup may be too much unless you have a huge tank, if it was me I'd first try with less amount than more to learn which amount works for your tank since Rowaphos is expensive. I've stopped using Rowaphos since adding Xenia and GSP (each isolated on large rock islands) which are thriving and sometimes works too well at removing PO4, I now have to turn the skimmer off sometimes.
edit - I just noticed in ur last post u have a 250 gal tank. in which case perhaps 1 cup may be necessary to lower PO4 from 2ppm

 

[Randy Holmes-Farley Verified Community Expert]

Well I only order 250 ml because that was supposed to be able to remove 3ppm if phosphate from 250 gallons. That's more phosphate and water than I have. But it seems you're telling me it not be enough?

Correct.

You have far more bound to rock and sand.

 

[EntitledSushi]

I have been struggling with phosphates for a while. They were as high as 2ppm. I have put in way more than the suggested amount of both Rowaphos and Phosguard in mesh bags in the sump. Probably 3x as much. I have a 75 gallon tank. The effect has been almost negligible. I am thinking that these really need a reactor to be effective, but I am reluctant to buy yet another thing that needs maintenance.

 

[Ferrell]

When I used GFO I mix with carbon in a reactor. Maybe cup of carbon to a tablespoon of GFO and run it at a trickle so it doesn’t strip it out to fast. Normally a couple of days to go from 0.3 to 0.1 just to give you an idea

 

[Randy Holmes-Farley Verified Community Expert]

I have been struggling with phosphates for a while. They were as high as 2ppm. I have put in way more than the suggested amount of both Rowaphos and Phosguard in mesh bags in the sump. Probably 3x as much. I have a 75 gallon tank. The effect has been almost negligible. I am thinking that these really need a reactor to be effective, but I am reluctant to buy yet another thing that needs maintenance.

Mesh bags are very slow for GFO since the particle size is small. That said, at 2 ppm phosphate, you will have to remove way more than 2 ppm to maintain lower levels as much will be bound to rock and sand.

 

[Wolf89]

Mesh bags are very slow for GFO since the particle size is small. That said, at 2 ppm phosphate, you will have to remove way more than 2 ppm to maintain lower levels as much will be bound to rock and sand.

I have rowaphos in a mesh bag, 250 ml. Roughly how long will it take to be filled to capacity?

 

[Randy Holmes-Farley Verified Community Expert]

I have rowaphos in a mesh bag, 250 ml. Roughly how long will it take to be filled to capacity?

It will depend on flow through it. With GFO, it might not expose the middle well at all if water is not forced through it.

 

[Wolf89]

Correct.

You have far more bound to rock and sand.

Maybe a cup at a time, changed after a few days to a week.

Well i added the 250 ml about a week ago, which is just a little more than a cup and my phosphates went from 2-3 +ppm to 0 in just 4 or 5 days. My corals really aren't too happy with the change. Was not expecting it to all disappear after what you said.
This was in a 220 gallon system.

 

[Pistondog]

Well i added the 250 ml about a week ago, which is just a little more than a cup and my phosphates went from 2-3 +ppm to 0 in just 4 or 5 days. My corals really aren't too happy with the change. Was not expecting it to all disappear after what you said.
This was in a 220 gallon system.

You are right, that is surprising.
How are you testing phosphate.

 

[Wolf89]

You are right, that is surprising.
How are you testing phosphate.

Rikka test kit

 

[Wolf89]

how long would phosphate take to bind to rock? Its only been this elevated for a month or 2 at most. I wonder if the tank being bare bottom has something to do with it? I also siphoned out all of the detritus in my sump, maybe 30 gallons total

 

[Pistondog]

how long would phosphate take to bind to rock? Its only been this elevated for a month or 2 at most. I wonder if the tank being bare bottom has something to do with it? I also siphoned out all of the detritus in my sump, maybe 30 gallons total

Test again in a couple of days.
I'm ignorant of how fast phosphate is taken up or released by rock.
The gfo will continue to absorb what's available in the water, and continue to collect what leaches out of the rock, but eventually, the gfo will become saturated and leaching will be measurable with the water test.

 

[Randy Holmes-Farley Verified Community Expert]

how long would phosphate take to bind to rock? Its only been this elevated for a month or 2 at most. I wonder if the tank being bare bottom has something to do with it? I also siphoned out all of the detritus in my sump, maybe 30 gallons total

2 seconds? As soon as it hits the sand, some will bind. Bare bottom obviously has less bound.