Extremely high phosphates in new 125 gallon tank

[Pod_01]

Before doing anything I would double/ triple check the results as mentioned. Phosphate is too critical to bring down to zero. Also do go slow.

I’m sure the rock from my old tank had bound up phosphates from the 2 years of use and now it’s releasing into the tank but at such a high concentration?

Rocks do not act like a sponge and soak up phosphates and or release phosphate.
They bind and unbind phosphates and what they bind or unbind is in equilibrium with the water column. So if you measure 0.1ppm your rocks have 0.1ppm.
As you remove PO4 from water column and depending on rock volume your new values will go down to let’s say 0.09ppm as phosphate unbinds and new equilibrium is reached but not higher.
Feeding, coral foods etc… will tend to bring it up.

If your reading is correct your old tank was likely running at that level.

Good luck,

 

[bshake]

Assume that your reading is correct (which I don't think it is) you should be able to knock down PO4 quickly with LC-based solutions. I've used Phosphate-E 7+ years ago but been using PhosphateRx the last 3 years w/o any issues. Just go slow and test your PO4 before & after. Just count drops into filter floss at night before bed since the water will be very cloudy for several hours. My SPS tank is running at 0.3 atm without any issues.

Is there a reason why you switched from phosphat E? To phosphate RX? I see more people use phosphate RX on here. Everyone recommends a 5 micron sock. What about dosing it in front of a Protine skimmer?

 

[bshake]

Before doing anything I would double/ triple check the results as mentioned. Phosphate is too critical to bring down to zero. Also do go slow.



Rocks do not act like a sponge and soak up phosphates and or release phosphate.
They bind and unbind phosphates and what they bind or unbind is in equilibrium with the water column. So if you measure 0.1ppm your rocks have 0.1ppm.
As you remove PO4 from water column and depending on rock volume your new values will go down to let’s say 0.09ppm as phosphate unbinds and new equilibrium is reached but not higher.
Feeding, coral foods etc… will tend to bring it up.

If your reading is correct your old tank was likely running at that level.

Good luck,

Thank you, I’m sure the old tank was super nigh since I was battling hair algae almost constantly. So since I got a ULR nitrate checker, was what I did correct to get a somewhat accurate reading. Dilute the tank water 1/9 and multiply the result by 10

 

[Pod_01]

Thank you, I’m sure the old tank was super nigh since I was battling hair algae almost constantly. So since I got a ULR nitrate checker, was what I did correct to get a somewhat accurate reading. Dilute the tank water 1/9 and multiply the result by 10

Sounds reasonable, what I am not sure if RO water (I am assuming RO was used) impacts the reading.
Some of these test kits do claim they are for freshwater vs. saltwater.

Alternatively you could take some water out, use the phosphat E and see if you get expected drop after use.

 

[bshake]

Sounds reasonable, what I am not sure if RO water (I am assuming RO was used) impacts the reading.
Some of these test kits do claim they are for freshwater vs. saltwater.

Alternatively you could take some water out, use the phosphat E and see if you get expected drop after use.

I used freshly mixed saltwater that was ready from the night before I did a water change. So 1LM of tank water and 9ML of clean saltwater.

 

[Pod_01]

I used freshly mixed saltwater that was ready from the night before I did a water change. So 1LM of tank water and 9ML of clean saltwater.

I would also measure the freshly mixed saltwater.
Some salts do contain PO4 and you may want to account for it.

Also PO4 in a salt mix is not a bad thing.

 

[bshake]

I would also measure the freshly mixed saltwater.
Some salts do contain PO4 and you may want to account for it.

Also PO4 in a salt mix is not a bad thing.

I’m using the tropic Marin pro reef salt. I actually wanna test it to see if there’s any PO4 in there and also I bought TDS meter to see how my RO water is looking.

 

[Xxflounderxx]

I've had experience with using phosphate e then testing with the hanna checker and the level rise there is something that throws off the test. Now I only use gfo. Try another test kit or icp. Learn from me tanked my phosphate to 0 the got dinoflagellates lost a bunch of coral

 

[Pod_01]

I’m using the tropic Marin pro reef salt. I actually wanna test it to see if there’s any PO4 in there and also I bought TDS meter to see how my RO water is looking.

TM pro reef salt has PO4 in it.

 

[Pod_01]

I've had experience with using phosphate e then testing with the hanna checker and the level rise there is something that throws off the test. Now I only use gfo. Try another test kit or icp. Learn from me tanked my phosphate to 0 the got dinoflagellates lost a bunch of coral

Interesting so there was interference.
Good information to have, OP don’t do what I mentioned.

Problem with ICP is that it measures element P, not Orthophosphate PO4 that test kits measure.
Some ICP companies do measure both but it is a separate test ,

In that report you get P, total calculated PO4 and the orthophosphate PO4.

 

[SDchris]

Rocks do not act like a sponge and soak up phosphates and or release phosphate.

Bacteria associated with the rock will cause phosphate to behave like that.

 

[bakbay]

Is there a reason why you switched from phosphat E? To phosphate RX? I see more people use phosphate RX on here. Everyone recommends a 5 micron sock. What about dosing it in front of a Protine skimmer?

I’ve personally found PhosphateRx to be more potent so comes in a compact size. They both should work fine. I drop into filter floss (10 micron?) before the skimmer. I have 6 tangs and they don’t seem to be affected by it.

 

[Pod_01]

Bacteria associated with the rock will cause phosphate to behave like that.

Bacteria usually consumes PO4. I am not sure how it can release it?

One of the ideas behind carbon dosing, feed the bacteria so it consumes PO4 and the corals consume the bacteria.
The other reasons people carbon dose is to control NO3/PO4. Again feed the bacteria and skimmer skins them out.

Unless the biofilm suddenly collapses …
I am not seeing how bacteria releases PO4 like a sponge.

Algae like GHA can get PO4 from the rock and that is why it is next to impossible to starve algae out without also starving all the corals.

I never seen PO4 just go up by itself, unless I added food source that had it.

Is there a paper I could read up on this? I like to understand the mechanism.

 

[SDchris]

Is there a paper I could read up on this? I like to understand the mechanism

Search using: polyphosphate, shallow marine/reef sediments, aerobic/anaerobic.

Some bacteria uptake phosphate in excess of their needs and store it, under aerobic conditions. They release the stored phosphate under anaerobic conditions.
IMO that cycle is the main driver of cyano blooms you see in a reef tank. Including the cyano that often appears when first starting carbon/vodka dosing.

 

[Spare time]

Be very careful with gfo or any chemicals right now. If the phosphate was really that high the corals would not be that happy. Something fishy is up with your testing and you don’t want to get rid of all your phosphates by accident

The only thing high phosphate may cause in most cases is brittle coral.

 

[Spare time]

Personally I would just toss in the gfo and call it a day. When the phosphates stop dropping, replace it. No need to panic or do something risky.

 

[slingfox]

As others recommended you should doublecheck your phosphate reading before doing anything. Test fresh salt water to see if it gives a reasonable reading. Take your tank water and have it tested at a trustworthy LFS.

If the issue is phosphates bound in your old rock and sand you could remove those and unbind phosphate via lanthanum in a bucket or container of some sort (assuming you don't have a bunch of coral glued to the rocks.

With all the equipment you have and are thinking of buying, you should consider getting a sump if possible.

 

[SDchris]

Is there a paper I could read up on this? I like to understand the mechanism.

This paper was a good read, but I can only now access an abstract. Maybe you can find the full copy
Nutrient dynamics in the sediments and water column on selected coral reefs on the West Coast of Unguja Island.

 

[Pod_01]

Search using: polyphosphate

I had the impression polyphosphates are not measured by our test kits…

Thank you for the abstract, interesting I guess that is the summary:

I am not sure how this works out in our tanks. If I have bare bottom or close to it, few rocks do I ever get anaerobic zone?
How much PO4 can the bacteria release over time in our reef tank? Do you recall if the article had some ratios?

Also interesting idea about cyano, I once had a bad outbreak when I had a crash and assumed the biofilm collapsed and PO4 was released. I just don’t recall a huge spike in PO4 measurements, they went up but I never got PO4 above the 1ppm range. I definitely had cyano…

Thank you for sharing. This P/PO4 subject is fascinating in the reef tank. Always some new wrinkle.

 

[SDchris]

I had the impression polyphosphates are not measured by our test kits…

Correct. Bacteria uptake orthophosphate and store it as polyphosphate . They can use it as an energy source when there is a lack of oxygen, which is then converted back to orthophosphate.
Rock / sand, they are pretty much interchangeable when talking nutrient dynamics.