Need some help with Phosphate levels - I cannot seem to keep them down

[Randy Holmes-Farley Verified Community Expert]

Gotcha, so pure GFO is giong to be the best as far as media goes at removing PO4, correct? Is it even possible for it to be effective in a media bag in the filter sock? Or does it absolutely need to be in a reactor?

I also feel like its depleting faster than anticipated, but that also aligns some with the massive swings i'll see in a single day that lead me to believe my rocks are just dumping PO4 into the system

GFO and aluminum oxide both work. Drawback is binding if other trace elements and aluminum release from the aluminum oxide.

If phosphate is high, rocks bind it. It’s just a fact of life. :)

 

[alex21720]

GFO and aluminum oxide both work. Drawback is binding if other trace elements and aluminum release from the aluminum oxide.

If phosphate is high, rocks bind it. It’s just a fact of life. :)

Sounds like a very unfortunate fact of life!

So is that to say that eventually the phosphates that are bound to my rocks and slowly (or sometimes rapidly) releasing will eventually die off?

Or is it better to just replace the rock with rock that doesn't have a ton of excess phosphate bound to it, cycle it, and swap it in?

 

[Randy Holmes-Farley Verified Community Expert]

Sounds like a very unfortunate fact of life!

So is that to say that eventually the phosphates that are bound to my rocks and slowly (or sometimes rapidly) releasing will eventually die off?

Or is it better to just replace the rock with rock that doesn't have a ton of excess phosphate bound to it, cycle it, and swap it in?

The amount on rock and sand surfaces is in constant equilibrium between the water and the surfaces. The more in the water, the more on the surfaces. If you try to raise the level in the water, some binds. If you try to lower it, some releases.

If you keep removing some, levels will come down.

 

[alex21720]

The amount on rock and sand surfaces is in constant equilibrium between the water and the surfaces. The more in the water, the more on the surfaces. If you try to raise the level in the water, some binds. If you try to lower it, some releases.

If you keep removing some, levels will come down.

Gotcha, appreciate your replies!

 

[mcarroll]

I mention this because I’m curious if bleaching rock can cause phosphate to leach out later.

It can cause the po4 to "leak out" of anything that was previously living on/in the rock and holding in its guts. ;) (Probably not just PO4, other organics too.)

Hard to imagine this accounting for more than trace amounts of PO4 if this started off as dry rock (ie no reef growth on it like sponges, et al).

From that point on, I’ve consistently battled high phosphates. Initially, levels were above the Hanna ULR range (>0.9).

Are you talking ppb or ppm? We know your Hanna ULR meter speaks "ppb".

If your post is in ppb, then your reading is not a high number at all.

Please clarify. (Hanna HI736 ULR Conversion table.)

Could you also clarify any further how you handled the rock outside the tank?

If the "phosphate mystery" began with your treatment of those few rocks, then:
A) you should be able to remove those rocks and the problem goes with them.
B) where in your treatment regime did the po4 come from?

I don't think this adds up....not so far at least.

I do weekly 5-gallon water changes on this 25-gallon tank. I’ve also had periods of battling hair algae and algae on the glass.

That's normal for a tank this age.

I feed primarily frozen mysis, about 1 cube every 2–3 days, and occasionally Neptune Systems Cross Over Diet.

That might be considered a lot (maybe not "too much") for a small tank like this, that is as young as it is.

Let us know on the ppm/ppb question.

IMO if you're talking ppb, then there's no issue.

If you're talking ppm, then I'm still not too concerned about the number per se, but it does seem high all things considered....I can't see a good explanation yet.

 

[alex21720]

I mention this because I’m curious if bleaching rock can cause phosphate to leach out later.

It can cause the po4 to "leak out" of anything that was previously living on/in the rock and holding in its guts. ;) (Probably not just PO4, other organics too.)

Hard to imagine this accounting for more than trace amounts of PO4 if this started off as dry rock (ie no reef growth on it like sponges, et al).

From that point on, I’ve consistently battled high phosphates. Initially, levels were above the Hanna ULR range (>0.9).

Are you talking ppb or ppm? We know your Hanna ULR meter speaks "ppb".

If your post is in ppb, then your reading is not a high number at all.

Please clarify. (Hanna HI736 ULR Conversion table.)

Could you also clarify any further how you handled the rock outside the tank?

If the "phosphate mystery" began with your treatment of those few rocks, then:
A) you should be able to remove those rocks and the problem goes with them.
B) where in your treatment regime did the po4 come from?

I don't think this adds up....not so far at least.

I do weekly 5-gallon water changes on this 25-gallon tank. I’ve also had periods of battling hair algae and algae on the glass.

That's normal for a tank this age.

I feed primarily frozen mysis, about 1 cube every 2–3 days, and occasionally Neptune Systems Cross Over Diet.

That might be considered a lot (maybe not "too much") for a small tank like this, that is as young as it is.

Let us know on the ppm/ppb question.

IMO if you're talking ppb, then there's no issue.

If you're talking ppm, then I'm still not too concerned about the number per se, but it does seem high all things considered....I can't see a good explanation yet.

You had my hopes up for a sec with the PPM/PPB. But it’s definitely PPM, as that’s what’s printed on the face of the checked. I’m guessing there are 2 versions of the ULR?

 

[KStatefan]

You had my hopes up for a sec with the PPM/PPB. But it’s definitely PPM, as that’s what’s printed on the face of the checked. I’m guessing there are 2 versions of the ULR?

Yes One reads in Phosphate ppm and the other reads in Phosphorous PPB

 

[Bruttall]

I dose diluted lanthanum chloride directly into my skimmer neck.
This is the exact product I use, https://tinyurl.com/33b4zv4y
Using Neptune APEX I dose 10ml directly into my skimmer neck, this has gradually been reduced over the last 2 years from nearly 30ml when I started.

I reduce 50ml of the Product into 1450ml of RODI and that is what I dose into the skimmer next.
Keeping my Phos around .06 has been really easy.

 

[alex21720]

I dose diluted lanthanum chloride directly into my skimmer neck.
This is the exact product I use, https://tinyurl.com/33b4zv4y
Using Neptune APEX I dose 10ml directly into my skimmer neck, this has gradually been reduced over the last 2 years from nearly 30ml when I started.

I reduce 50ml of the Product into 1450ml of RODI and that is what I dose into the skimmer next.
Keeping my Phos around .06 has been really easy.

A few questions on this

Why do you dose directly into the skimmer neck instead of just into the sump?
Do you do this at night so you don't get the negative effects of a cloudy tank?
And when you say you dose 10ml, you're dosing 10ml of your diluted solution, correct? How did you settle on that number?

 

[Jimbo327]

Phosphate will bind to your rock and sand in equilibrium with your tank water. Even if you change out 100% of your tank water....once you refill with clean water....the phosphate will unbind from the rock and go into the water. Hence, it is not that easy to lower phosphates with just water changes.

Chaeto and more carbon dosing will lower nitrates much more than phosphates.

Since you don't have a sump or skimmer, then it's easiest to get bag of gfo and remove phosphates with that. LC is better when you have filter/sump/skimmer to filter out the phosphate precipitates.

 

[mcarroll]

You had my hopes up for a sec with the PPM/PPB. But it’s definitely PPM, as that’s what’s printed on the face of the checked. I’m guessing there are 2 versions of the ULR?

Yes, now we know for sure which kit you have. :)

If you run a test on your tap water (or a standard solution) does the Hanna give sane/expected results?

Another test is to run the test in triplicate on the same water sample. You should be able to get REALLY close the to same result every time....if not, then the results may not be trustworthy.

If it's the right model of Checker, the only thing left to know is whether it's acting right. If it is, then your number is what it is.

The main reason for the continued scrutiny is that I still don't understand how this wasn't a problem before you scrubbed a rock...

aiptasia on one of the rocks. To deal with it, I pulled that rock, bleached it for a week, then conditioned it to make sure no chlorine remained before putting it back.

...and now it is a problem. I don't get how this supports the "leaching" theory. If you pull that rock, does the issue go away with it?

"Leaching" certainly happens, chemically speaking, but why from this? Why was your bleaching of the aiptasia rock (singular) able to kick off this phosphate issue?

So....more questions:

• How are your NO3 readings?
• You mentioned aiptasia. How is algae growth around the tank?
• Do you have a FTS posted, or can you?

Can you dilute a sample by 50% with RODI and try to get a complete reading so we can infer your total PO4 ppm?

 

[Bruttall]

A few questions on this

Why do you dose directly into the skimmer neck instead of just into the sump?
Do you do this at night so you don't get the negative effects of a cloudy tank?
And when you say you dose 10ml, you're dosing 10ml of your diluted solution, correct? How did you settle on that number?

Lanthanum binds Phos and it needs a method of entrapment or exportation. The 2 viable methods are Dose into skimmer Neck, or Dose into a Sock.
I do not use socks for filter so I dose into the skimmer the Phos binds in the foam and is exported without any of the Lanthanum actually exporting itself into my tank. There are potential said effects to some fish, Tangs mentioned mostly which is another reason why I isolated the Dosing into my skimmer.

When I started this I monitored my PO4 every 2 days and I adjusted the Dose. I was adding nearly 40ml a day early on but as my tank has matured I have been able to reduce that dose amount. Your results will vary, I run a 300g display with a 125g tank as a sump, nearly 370g water total.

It runs 24/7 dose schedule on my Apex, 10ml of reduced solution into the Skimmer Neck over a 24h period.

 

[rsach]

Lanthanum binds Phos and it needs a method of entrapment or exportation. The 2 viable methods are Dose into skimmer Neck, or Dose into a Sock.
I do not use socks for filter so I dose into the skimmer the Phos binds in the foam and is exported without any of the Lanthanum actually exporting itself into my tank. There are potential said effects to some fish, Tangs mentioned mostly which is another reason why I isolated the Dosing into my skimmer.

When I started this I monitored my PO4 every 2 days and I adjusted the Dose. I was adding nearly 40ml a day early on but as my tank has matured I have been able to reduce that dose amount. Your results will vary, I run a 300g display with a 125g tank as a sump, nearly 370g water total.

It runs 24/7 dose schedule on my Apex, 10ml of reduced solution into the Skimmer Neck over a 24h period.

I've always been scared to use Lanthanum as I have Tangs, but based on your experience it seems like there is none of it exported to the display if dosed directly into the skimmer neck. Do you have any Tangs? How are you dosing it via a doser, are you mixing it with water or is it 10ml at full concentration? Thanks!

 

[Randy Holmes-Farley Verified Community Expert]

I've always been scared to use Lanthanum as I have Tangs, but based on your experience it seems like there is none of it exported to the display if dosed directly into the skimmer neck. Do you have any Tangs? How are you dosing it via a doser, are you mixing it with water or is it 10ml at full concentration? Thanks!

I would not assume this is definitive.

 

[Tidal Gardens Verified Sponsor]

Phosphate can be bound up in the rock and then be released into your water. It could take a long time for it to fully leach out of the rockwork. If you are reducing it by using GFO, please go slow. You can make more of an issue stripping your tank to zero rather then having higher phosphate levels. It took nearly a year to do this in one of our systems.

 

[rsach]

I've always been scared to use Lanthanum as I have Tangs, but based on your experience it seems like there is none of it exported to the display if dosed directly into the skimmer neck. Do you have any Tangs? How are you dosing it via a doser, are you mixing it with water or is it 10ml at full concentration? Thanks!

I would not assume this is definitive.

Thanks for your feedback. Do you think Brightwell Phosphate-E is a safer alternate, if dosing in the skimmer neck? Or should I just stick to GFO?

 

[BryanM]

Thanks for your feedback. Do you think Brightwell Phosphate-E is a safer alternate, if dosing in the skimmer neck? Or should I just stick to GFO?

It is a lanthanum product, so it has the same issues with tangs. Many people dose it in to a skimmer with success, but IMO GFO is much safer.

 

[Randy Holmes-Farley Verified Community Expert]

Thanks for your feedback. Do you think Brightwell Phosphate-E is a safer alternate, if dosing in the skimmer neck? Or should I just stick to GFO?

It is lanthanum and likely carries the same risk to tangs as any brand, assuming impurities are not the tox cause.

 

[rsach]

It is lanthanum and likely carries the same risk to tangs as any brand, assuming impurities are not the tox cause.

Thanks @Randy Holmes-Farley and @BryanM , I will stick with GFO. Lanthanum makes me nervous, I just got excited reading the results from the post.

 

[mook1178]

To me it sounds like you have a lot of PO4 in the rocks. You have small enough tank that doing 50% water changes twice a week is what I would do. I did that in my 75 gal and got all PO4 down in about a month.