Last bit of phosphate

[coil1002]

I got my phosphate down to 0.36 but cant seem to get it any lower. My nitrates are at 0 both tested with red sea kits. but that last bit of phosphate wont go away. I have 3 damsels and an algae bleeny in a 93 gallon cube with a 20 gallon sump 100 pounds of aged live rock and a eshopps s-120 skimmer. 20 % water changes every week and i change the filter sock every three days.

The tank was running for 3 years down for 4 days and then reset up same rock, same sand. Sand was washed out before re use.

Should I try a phosban reactor? I would like to avoid dropping them to zero super fast. Any suggestions would be greatly appreciated.

 

[saltyfilmfolks]

I would look at phosphate RX first.
Lanthanum chloride.

Melev has a good tutorial floating around.

It removes the po4 from the surfaces rather than leeching them back off the rocks.

And both methods can drop it too fast if you don't go slowly.

 

[Randy Holmes-Farley Verified Community Expert]

I would look at phosphate RX first.
Lanthanum chloride.

Melev has a good tutorial floating around.

It removes the po4 from the surfaces rather than leeching them back off the rocks.

Does it? How do you know that?

That doesn't seem plausible to me.

 

[Randy Holmes-Farley Verified Community Expert]

I got my phosphate down to 0.36 but cant seem to get it any lower. My nitrates are at 0 both tested with red sea kits. but that last bit of phosphate wont go away. I have 3 damsels and an algae bleeny in a 93 gallon cube with a 20 gallon sump 100 pounds of aged live rock and a eshopps s-120 skimmer. 20 % water changes every week and i change the filter sock every three days.

The tank was running for 3 years down for 4 days and then reset up same rock, same sand. Sand was washed out before re use.

Should I try a phosban reactor? I would like to avoid dropping them to zero super fast. Any suggestions would be greatly appreciated.

If nitrate is down very low, balanced methods such as coral or macroalgae uptake cannot lower phosphate further.

Some sort of binder is in order (or nitrate dosing and balanced export).

GFO is a fine way to go, but lanthanum or aluminum oxide also work.

Phosphate In The Reef Aquarium
https://www.reef2reef.com/blog/?p=3184

 

[saltyfilmfolks]

Does it? How do you know that?

That doesn't seem plausible to me.

What part sir?

Mostly from what you've written about phosphate.
Phosphate binds to rock and sand(argonite) by contact through the water. Onece bound , po4 leaches back off the rock into the wc. Gfo then binds it. I belive because it attracts the ions faster then aragonite.

Lanthanum dissolves the bond between the po4 and argonite (Im honestly not familiar enough with that process), releasing it back into wc where it has to be removed mechanically.

Myself I use a refugium and way too many corals. If my po4 gets too high I just cut back on feeding and increase wc frequency. It's slower but effective. And less expensive.

 

[Randy Holmes-Farley Verified Community Expert]

What part sir?

Mostly from what you've written about phosphate.
Phosphate binds to rock and sand(argonite) by contact through the water. Onece bound , po4 leaches back off the rock into the wc. Gfo then binds it. I belive because it attracts the ions faster then aragonite.

Lanthanum dissolves the bond between the po4 and argonite (Im honestly not familiar enough with that process), releasing it back into wc where it has to be removed mechanically.
.

Did I write that?

I expect the lanthanum binds primarily to phosphate that is in the water column. Phosphate on the rock is in constant equilibrium with phosphate in the water. It goes back and forth, and lanthanum grabs it when it is in the free form in the water. That's how the levels can decline in seawater with phosphate in it, when lanthanum is added, or in a swimming pool, for that matter.

Yes, a lanthanum ion may bind to a phosphate that is exposed on the surface of calcium carbonate, with the phosphate attached to a calcium underneath and a lanthanum on top of it. That whole layer might rearrange itself, and form a coating of mostly lanthanum carbonate, but I've not seen any evidence that this does happen, or if it does, how extensive of a mechanism it may be.

 

[coil1002]

If nitrate is down very low, balanced methods such as coral or macroalgae uptake cannot lower phosphate further.

Some sort of binder is in order (or nitrate dosing and balanced export).

GFO is a fine way to go, but lanthanum or aluminum oxide also work.

Phosphate In The Reef Aquarium
https://www.reef2reef.com/blog/?p=3184

Should I consider dosing nitrates to balance things out first?

 

[coil1002]

Should I consider dosing nitrates to balance things out first?

Never mind you answered that in your reply

 

[coil1002]

Well come to find out my red sea kit only goes down to 0.36. I got a hannah checker and it was at 0.101 after adding the gfo its now down to 0.044. and I was able to get my nitrates up to 0.25 by adding a tang.

 

[roberthu526]

I am having the same issue. I have been running BRS high capacity GFO for a month now and my phosphate level just fluctuates between 0.1 and 0.4 ppm. I just changed out the GFO today but honestly I am not hopeful at all.
I have been dosing NOPOX for a few months and nitrate has been stable at 1-2 PPM since I started dosing NOPOX. It’s the phosphate I can’t get down at all...

 

[coil1002]

What test kit you using?

 

[spiraling]

Never mind you answered that in your reply

I have found adding nitrates when they are that low will also drop phosphates. Can I ask why you want to drop them? Are you seeing issues?

 

[coil1002]

I didn't actually want to drop the nitrates the where around 2 which for me is not a big deal they just bottomed out. I bought this tank used and it was up for 3 years before I got it.

It was down for 4 days and then I reset it up. The nitrates were fine and then just dropped out. I stock real light on the fish though.

I wanted to drop my phosphate as I was going through the new tank uglies. And I thought I got stuck at 0.35. But it looks like it was my test kit. I bought more fish and it brought the nitrates up which was a good thing.

 

[spiraling]

This is just my opinion but I'm not convinced lowering the phosphates gets rid of the uglies. I think having P fuels them on faster. There is still a lot to understand why most tanks go through this 'uglies' phase and dropping P and/or N to 0 seems to hurt the corals in this phase. purely anecdotal on my part, but that what I gather from reading posts.

 

[coil1002]

I tend to agree. Dropping my p only slowed the uglies I still went through diatoms gha an cyno.i was hoping it would not happen since the tank was only down four days and the water and the rock where kept. Maybe stirring all of it up kicked it off. This is one of many tanks I have started over the years and they all go through that phase no matter what I do.

 

[Randy Holmes-Farley Verified Community Expert]

I am having the same issue. I have been running BRS high capacity GFO for a month now and my phosphate level just fluctuates between 0.1 and 0.4 ppm. I just changed out the GFO today but honestly I am not hopeful at all.
I have been dosing NOPOX for a few months and nitrate has been stable at 1-2 PPM since I started dosing NOPOX. It’s the phosphate I can’t get down at all...

How often do you change the GFO? It depletes fairly fast at 0.4 ppm.

 

[roberthu526]

What test kit you using?

Hanna ULR phosphorus checker

 

[roberthu526]

How often do you change the GFO? It depletes fairly fast at 0.4 ppm.

I think that was my issue. I changed GFO last night and tonight I just ran a test and phosphate level dropped from 0.3ppm to 0.042 ppm via Hanna ULR checker.

 

[Randy Holmes-Farley Verified Community Expert]

I think that was my issue. I changed GFO last night and tonight I just ran a test and phosphate level dropped from 0.3ppm to 0.042 ppm via Hanna ULR checker.

Hopefully it will stay down for a while.

Happy Reefing.

 

[roberthu526]

Hopefully it will stay down for a while.

Happy Reefing.

Thanks. Unfortunately it came back up to 0.07 ppm tonight... I feel like I need to change GFO daily now..