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View Full Version : I can't get my phosphates under .66


reefer1970
09/25/2017, 10:20 AM
A few months ago I realized my phosphates were at 2. Got a Hanna checker, weekly water changes, went to 100% gfo in my reactor and switch out every 2-3 days, 1/2 cup of phosguard in the sump every week or maybe every other, got a new Reef octopus skimmer, continued use and cleaning of my algae scrubber and refugium, and almost no food or at least frozen food for the fish. Things seem to stay around .66

Do I need to switch out gfo more often? But do I have to do that long term? Does it sound like I have phosphates bound to the live rock? I did use to feed a lot of frozen food and feed Phyto Feast if


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mcgyvr
09/25/2017, 11:32 AM
The GFO will be much more effective when run in a reactor and you should be able to monitor the output and when phosphates are detected that should let you know its time to replace it..

What happened though? overfeeding for a while now?
With an ATS in play you must have really been overfeeding bad...

rtparty
09/25/2017, 11:40 AM
What are your nitrates? If they are too low then you will never get your phosphates down. They have to be balanced to the proper ratios

mcgyvr
09/25/2017, 11:50 AM
What are your nitrates? If they are too low then you will never get your phosphates down. They have to be balanced to the proper ratios

Not for GFO to work AFAIK...

rtparty
09/25/2017, 12:02 PM
Not for GFO to work AFAIK...GFO may pull them down but that doesn't mean the tank is in balance

mcgyvr
09/25/2017, 01:11 PM
GFO may pull them down but that doesn't mean the tank is in balance

Your statement made it seem like GFO use/efficiency is related to nitrate levels which AFAIK.. its not..

reefer1970
09/25/2017, 01:23 PM
What are your nitrates? If they are too low then you will never get your phosphates down. They have to be balanced to the proper ratios



My nitrates were always very high as well at 50ppm? I have been vodka dosing for a couple of months and they are now down very low (can't remember what they were last) my macro production has slowed way down, guessing that means the nutrients are lowering. Am I supposed to add nitrates??


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reefer1970
09/25/2017, 01:27 PM
The GFO will be much more effective when run in a reactor and you should be able to monitor the output and when phosphates are detected that should let you know its time to replace it..

What happened though? overfeeding for a while now?
With an ATS in play you must have really been overfeeding bad...



I do use a reactor and it gets exhausted very quick. Yes, I used a homemade frozen seafood stew trying to copy Rods Food and I think that did it . I'm just wondering why I've plateaued at .66 ppm.


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rtparty
09/25/2017, 01:54 PM
Your statement made it seem like GFO use/efficiency is related to nitrate levels which AFAIK.. its not..Sorry that was not my intent. I was hoping to point out that the phosphates not dropping on their own could be an imbalance issue with nitrates. My reply was semi rushed

rtparty
09/25/2017, 01:56 PM
My nitrates were always very high as well at 50ppm? I have been vodka dosing for a couple of months and they are now down very low (can't remember what they were last) my macro production has slowed way down, guessing that means the nutrients are lowering. Am I supposed to add nitrates??


Sent from my iPhone using TapatalkI'm not a chemist so I'll let those with a better understanding explain how the nitrate to phosphate ratio works. I just know they need to be balanced and when someone plateaus and can't get phosphates down, it's usually due to a lack of nitrates.

Hopefully @bertoni can chime in (or anyone else with a much better understanding)

mcgyvr
09/25/2017, 02:05 PM
I do use a reactor and it gets exhausted very quick. Yes, I used a homemade frozen seafood stew trying to copy Rods Food and I think that did it . I'm just wondering why I've plateaued at .66 ppm.
k

Output < Input ;)

It could be that its bound up in your rock/sand,etc... which from my understanding is that yes that can take a while to work its way out..

With levels that high GFO could be exhausted very quickly..
But as soon as the output from the reactor is not zero then the GFO is exhausted.. I suspect there is a flow rate variable in there somewhere though..


And yes there is redfields ratio... https://en.wikipedia.org/wiki/Redfield_ratio but thats a whole different discussion..

jda
09/25/2017, 02:18 PM
It does sound like the rock and/or sand is a reservoir. It can take a long time and a lot of GFO - buy the 5G bucket the next time that you purchase.

It should start to slowly go down.

bertoni
09/25/2017, 04:13 PM
The GFO can reduce the phosphate level whatever the nitrate level might be, but it might take a lot of media. Once the output of the reactor matches the water column as far as phosphate readings, the media is shot. A few hours might be enough if the phosphate level is that high.

You could try ramping up the amount of GFO and changing it more often, but if that starts to seem expensive, you could consider using lanthanum chloride (SeaKlear phosphate reducer) or something similar. It's some tedious to use because it produces a precipitate that should be removed via a filter sock, but it's much cheaper per unit of phosphate removed.

mako61
09/25/2017, 04:47 PM
melevsreef has a youtube video about Phosphate Rx usage. Correct me if Im wrong I think is lanthanum chloride. He seems to like/use the stuff instead of GFO.

bertoni
09/25/2017, 07:01 PM
It does seem to be another lanthanum chloride product. It should be fine, if used properly.

Alfrareef
09/26/2017, 05:54 PM
Hi.
If you allow me, why donít you do 2 large water changes 1week apart? That should reduce the numbers and then you could use GFO or similar...
Trying to PO4 with GFO itís a waste of time and money. How long itís the tank running

zachfishman
09/27/2017, 08:45 PM
What kind of system is this? What size? Phosphates at those levels arenít an issue if this is FO or FOWLR unless you are facing tough algae issues.

I recommend a hefty reactor full of Rowaphos (highest capacity GFO I have found bar none) which you can keep on regenerating (http://www.advancedaquarist.com/2010/10/chemistry).

Optionman
09/28/2017, 06:57 AM
Iíll play the contrarian. Who cares if your nitrate and phosphate levels are elevated unless youíre having a problem. I have higher levels then you and get great growth across the board with minimal algae issues. Iím afraid of unintended consequences if I were to aggressively chase zero.

Just my opinion. Stability is preferred over perfection.


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reefer1970
09/28/2017, 07:29 AM
Because I'm having some coral health issues that have seemed to get better when I started lowering phosphates


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jda
09/28/2017, 09:49 AM
Chasing them to zero is unnecessary and dumb. Getting them lower is smart. I know that the world like right/wrong, left/right and all kinds of polar opposites now, but the middle ground is a good place to be. Shoot for P around .10 to start - I like to be lower, but this works for most folks.

dkeller_nc
09/28/2017, 01:31 PM
So a couple of things to check before you get too far down the road of "it's not working".

First perform a control assay to make sure that you're using the Hanna Checker correctly. The Phosphate/Phosphorus checkers in particular aren't simple to get right - considerably more nuanced than an alkalinity titration, for example. To do this, make up a batch of new saltwater and run the test. If you get anything over a few ppb, you're either performing the test incorrectly, or your water source has an unreasonably high phosphate concentration that you'll need to address.

Second, on the input side of things, make sure that the home-brew seafood mixture you're making does not include seafood that's been preserved with tripoly phosphate. This is a common additive in, for example, scallops. Not related to the phosphate side of things, but also ensure that you're using wild-caught shrimp. Farmed shrimp can have an unreasonably high concentration of medications that you don't want in your fish (or you, for that matter).

If you eliminate the new salt water/RODI as a source of the phosphate, and you're sure that you're getting accurate test readings, then it is indeed possible that you've got a lot of phosphate adsorbed into your sand and/or rock, and it is leaching back out into the water column as fast as the phosphate-adsorption media is removing it. If that's the case, there's little you can do except keep up good tank hygiene and wait it out.

I would personally not recommend lanthanum chloride. While if used correctly (dosed into a filter sock, very gradually) it will rapidly reduce the phosphate concentration in the water column, the danger is that it's too effective. You can easily kill corals overnight by crashing the phosphate concentration of the water if the corals have been living in high phosphate concentrations for a number of months. Instead, you'd be far better off by slowly reducing the phosphate over a 6 week period with water changes and GFO use.

Remember, nothing good happens quickly in a reef tank!