Help phosphates

[Leon5962]

Hi I have a new 200 gal tank running for 5 week but I can keep my phosphate up even dosing neophose they keep bottoming out any ideas ?

 

[GSPClown94]

Calcium carbonate surfaces can bind a lot of phosphate from the water column. You may just need to continue dosing more phosphate to the tank.

 

[CHSUB]

How are you testing, what’s in the tank, do you need po4 because corals are suffering? ….you just want a po4 reading on a hobby test kit, so dose more!

 

[Leon5962]

How are you testing, what’s in the tank, do you need po4 because corals are suffering? ….you just want a po4 reading on a hobby test kit, so dose more!

Hanna checker getting Dinos

 

[Leon5962]

Calcium carbonate surfaces can bind a lot of phosphate from the water column. You may just need to continue dosing more phosphate to the tank.

Already dose 2 bottles of neophose maybe is not strong enough

 

[CHSUB]

Hanna checker getting Dinos

You get dinoflagellate because it’s a new tank, not zero po4….don’t believe the propaganda!

 

[Fish Fan]

According to RHF, the Neophos product is a weak solution:
https://www.reef2reef.com/threads/phosphate-dosing-advice.892887/post-9907617
Here's Miami Reef's guide to dosing phosphate if you decide that you need to:
https://www.reef2reef.com/threads/diy-phosphate-dosing-recipe.1109919/
Hope that helps!

 

[GSPClown94]

Already dose 2 bottles of neophose maybe is not strong enough

I've never used that product so I'm not sure. It might be cheaper to mix your own solution using some trisodium phosphate.

 

[TankYouVeryMuch]

As someone else mentioned, it readily binds to calcium. This is why it’s problematic, because it can make the calcium that corals need to build their skeletons unavailable because it’s bound up with phosphate.

For that reason, be very careful with soaking. You might see no change at all until you hit saturation point and then it’ll skyrocket. Make sure you’re using a sensitive tester like Hanna ULR once you get it dialed in, but you can use cheaper tests and test more frequently until then.

 

[GSPClown94]

As someone else mentioned, it readily binds to calcium. This is why it’s problematic, because it can make the calcium that corals need to build their skeletons unavailable because it’s bound up with phosphate.

I was only talking about calcium carbonate surfaces like live rock or sand binding phosphate. I believe dissolved calcium in the water behaves differently due to other dissolved ions that prevent precipitation in saltwater but I lack the chemistry background to fully understand this relationship.

 

[TankYouVeryMuch]

As someone else mentioned, it readily binds to calcium. This is why it’s problematic, because it can make the calcium that corals need to build their skeletons unavailable because it’s bound up with phosphate.

I was only talking about calcium carbonate surfaces like live rock or sand binding phosphate. I believe dissolved calcium in the water behaves differently due to other dissolved ions that prevent precipitation in saltwater but I lack the chemistry background to fully understand this relationship.

My understanding (as a non-chemist) is that it can bind to calcium in the water if conditions are right, and precipitate out as calcium phosphate. Drops in pH can break apart that bond, releasing phosphate (and calcium) back into the water. Some bacteria do this too, consuming the phosphate and leaving behind calcium, but both are likely to be a slow process in a typical reef rank.

This is also another benefit of “cured” live rock—the phosphate has already been bound up to the rock, meaning increased stability over the first few weeks to months versus dry rock.

Hopefully someone will correct me if my basic understanding is wrong, and I know I’m oversimplifying.

 

[Randy Holmes-Farley Verified Community Expert]

As someone else mentioned, it readily binds to calcium. This is why it’s problematic, because it can make the calcium that corals need to build their skeletons unavailable because it’s bound up with phosphate.

For that reason, be very careful with soaking. You might see no change at all until you hit saturation point and then it’ll skyrocket. Make sure you’re using a sensitive tester like Hanna ULR once you get it dialed in, but you can use cheaper tests and test more frequently until then.

I don’t think that’s the rationale for whatever impact phosphate has on calcification.

There also is not a sudden saturation point. The higher phosphate goes, the more
Binds.

 

[Randy Holmes-Farley Verified Community Expert]

My understanding (as a non-chemist) is that it can bind to calcium in the water if conditions are right, and precipitate out as calcium phosphate. Drops in pH can break apart that bond, releasing phosphate (and calcium) back into the water. Some bacteria do this too, consuming the phosphate and leaving behind calcium, but both are likely to be a slow process in a typical reef rank.

This is also another benefit of “cured” live rock—the phosphate has already been bound up to the rock, meaning increased stability over the first few weeks to months versus dry rock.

Hopefully someone will correct me if my basic understanding is wrong, and I know I’m oversimplifying.

It binds to calcium carbonate mineral surfaces, not calcium in the water at the levels we attain.

 

[TankYouVeryMuch]

As someone else mentioned, it readily binds to calcium. This is why it’s problematic, because it can make the calcium that corals need to build their skeletons unavailable because it’s bound up with phosphate.

For that reason, be very careful with soaking. You might see no change at all until you hit saturation point and then it’ll skyrocket. Make sure you’re using a sensitive tester like Hanna ULR once you get it dialed in, but you can use cheaper tests and test more frequently until then.

I don’t think that’s the rationale for whatever impact phosphate has on calcification.

There also is not a sudden saturation point. The higher phosphate goes, the more
Binds.

I can’t remember where I saw it (maybe a BRS video?) but there was some testing where they saw a pattern of phosphate suddenly jumping after a certain point. I’ll see if I can find it again, but either way do you happen to know what the mechanism would be that causes this?

 

[Sophie"s mom]

Following because I too am having this problem. I am in no way, shape or form a chemically knowledgeable person. My nitrates stay between 20 and 30ppm. My phosphate has always stayed between .02 and .08. Now over the last few weeks, for some reason it keeps bottoming out. I have been adding Neo Phos, which does bring it back up to .03 (using a Hanna ULR) but a few days later, it is back down again. Tank is 2 years old, with about 75lbs. of LR. and a ton of coralline algae. My brain is already full, from work stuff, so I am not wanting to get into the science of it. So I will follow here.

 

[Randy Holmes-Farley Verified Community Expert]

I can’t remember where I saw it (maybe a BRS video?) but there was some testing where they saw a pattern of phosphate suddenly jumping after a certain point. I’ll see if I can find it again, but either way do you happen to know what the mechanism would be that causes this?

I do not believe it happens the way that is described, regardless of what BRS may say. Phosphate binding to aragonite in seawater is well studied in the scientific literature.

What does happen is that at any phosphate concentration in the water, a fixed amount is on the mineral surface in equilibrium with the water. Any time you try to adjust the amount in the water, some will add to or come off of the surfaces.

If you start with bare calcium carbonate surfaces, and repeatedly add, say, 0.1 ppm phosphate, you may find that nearly all
of it binds for a while. With each addition, there is a larger and larger fraction of each dose remaining in the water and a smaller fraction that binds.

Eventually you may find that most of what you add stays in the water. It is not any sort of sudden effect, unless you are not measuring after each dose or the doses are exceptionally large.

 

[Leon5962]

Looks like reef roids did the trick am up to .1 don’t have any corals in tank yet