HIGH PHOSPHATE CAUSE

[Icedog]

I've been battling high phosphates (and resultant alga) for three months now and have been unable to decipher the cause of such. On Saturday I do a weekly 10% water change, vacuuming the gravel and blowing off the rocks, yet my phosphates are still at 0.3. Yesterday (Wednesday, mid-week) I also did a 15% water change while vacuuming out the sump - thought there might be some detritus in there that is causing the problem. Yet today my phosphates are still at 0.3!

I've been feeding the same amount of the same frozen food for the past two years, so I don't think that's the issue. The only other variable I can think of is a small piece of rock I had placed in the tank a few months ago. So I'm thinking that maybe it's leaching phosphates into the tank???

So I'm considering testing the rock for phosphate leaching:

1. Put some newly mixed salt water in a bucket and test it for phosphates (with Hanna ULP Checker).

2. Put the rock in question in the bucket of salt water, wait 5-7 days, and test it again for phosphate (again, with Hanna ULP Checkeer).

Does this make sense? I know there are a myriad of ways to lower the phosphate, but I'm really trying to find out what the source of the high phosphate levels might be!

 

[Reefahholic]

How old is the tank? Did this start right at the time you added the rock? What was the PO4 level before?

Hanna ULP?

 

[Icedog]

How old is the tank? Did this start right at the time you added the rock? What was the PO4 level before?

Hanna ULP?

The tank is about 3 1/2 years old. The phospates have always been around 0.1, and the increase started about a month before I added the rock. I know this doesn't really point to the rock as the root cause, but I'm trying to weed out all of the culprits.

And yes, I'm using the Hanna ULP Checker for my testing.

 

[Reefahholic]

The tank is about 3 1/2 years old. The phospates have always been around 0.1, and the increase started about a month before I added the rock. I know this doesn't really point to the rock as the root cause, but I'm trying to weed out all of the culprits.

And yes, I'm using the Hanna ULP Checker for my testing.

Could be anything. Nothing else was added.?


Never heard anybody refer to the Hanna Phosphorus or Phosphate ULR as ULP.

 

[Charlie the Reefer]

So recently my phosphates were consistently high, like .4-.5. Although I changed multiple things to fix it, one thing I discovered was my RODI had .15 PPM phosphate. So... I was topping off with phosphate water, which I'm sure contributed. Also, my TDS was only reading 1!

Anyways, I replaced the RODI filters and problem gone. So, maybe check your RODI filters/test your RODI water for phosphates!

Good luck.

 

[Icedog]

Could be anything. Nothing else was added.?


Never heard anybody refer to the Hanna Phosphorus or Phosphate ULR as ULP.

So sorry - my error. I should have stated that item as the Hanna ULR Phosphate Checker. You're absolutely correct.

 

[Icedog]

So recently my phosphates were consistently high, like .4-.5. Although I changed multiple things to fix it, one thing I discovered was my RODI had .15 PPM phosphate. So... I was topping off with phosphate water, which I'm sure contributed. Also, my TDS was only reading 1!

Anyways, I replaced the RODI filters and problem gone. So, maybe check your RODI filters/test your RODI water for phosphates!

Good luck.

Tks for the suggestion.

I just tested the phosphates in my RODI water jug and it was 0.01. But I wasn't sure if these results were valid using a Hanna Marine checker. So I also tested the phosphates in the mixed salt water jug, and that was 0.03.

Since the water doesn't seem to be the problem, I took the small piece of rock I described earlier and put it in a large bowl of salt water from the jug. Figured I'd let it sit for a week and test it again for phosphates.

Any other ideas would be appreciated. This is driving me nuts!

 

[rhostam]

So recently my phosphates were consistently high, like .4-.5. Although I changed multiple things to fix it, one thing I discovered was my RODI had .15 PPM phosphate. So... I was topping off with phosphate water, which I'm sure contributed. Also, my TDS was only reading 1!

Anyways, I replaced the RODI filters and problem gone. So, maybe check your RODI filters/test your RODI water for phosphates!

Good luck.

Curious. I think I need to test my RODI. I've been battling persistently high PO4 for almost a year now. It's finally come down because I'm down to the last resort. The average high was 0.4ish and peaked at 0.78. Now down to 0.19 and holding more or less (with treatment). Before any of this and what I thought precipitated the spike, my readings were consistently 0.03-0.05ish. Testing using both the regular and ULR Hanna Phosphate kits.

I think my rock just absorbed so much during the high period that it's finally starting to leech out in enough quantity to get it to be consistently lower. Still have a few more week journey, I imagine, but I never thought to test RODI. How silly of me.

 

[Icedog]

Curious. I think I need to test my RODI. I've been battling persistently high PO4 for almost a year now. It's finally come down because I'm down to the last resort. The average high was 0.4ish and peaked at 0.78. Now down to 0.19 and holding more or less (with treatment). Before any of this and what I thought precipitated the spike, my readings were consistently 0.03-0.05ish. Testing using both the regular and ULR Hanna Phosphate kits.

I think my rock just absorbed so much during the high period that it's finally starting to leech out in enough quantity to get it to be consistently lower. Still have a few more week journey, I imagine, but I never thought to test RODI. How silly of me.

Interesting! What do you think precipitated the phosphate spike? And what treatment did you use to finally lower it?

 

[rhostam]

Interesting! What do you think precipitated the phosphate spike? And what treatment did you use to finally lower it?

I made a mix of food for the AFS that included ReefRoids and didn’t notice until duncans started looking sad.

Water changes, GFO, adding roller fleece, reduce feeding, etc, to lower over monthss was not enough. But it takes a lot to keep things even momentarily depressed.

I finally am trying Tropic Marin’s Elimi-Phos Rapid. I’m finally pulling out the PO4 in noticeable quantities. I think the rocks are now leeching what they have held onto foot so long and I feel PO4 will stabilize soon here.

 

[Icedog]

Five days ago I had put the rock suspected of leaching in a bowl of salt water. And today I tested it for phosphates. The result was 0.18 - this seemed a bit high to me! Especially considering that the original phosphate level on that salt water was 0.03!

Any thoughts on this? And any ideas as to what I could use to dissolve the phosphate out of the rock, so that I can put it back into the tank?

 

[Dan_P]

Five days ago I had put the rock suspected of leaching in a bowl of salt water. And today I tested it for phosphates. The result was 0.18 - this seemed a bit high to me! Especially considering that the original phosphate level on that salt water was 0.03!

Any thoughts on this? And any ideas as to what I could use to dissolve the phosphate out of the rock, so that I can put it back into the tank?

By now the rock would have adsorbed PO4 from the aquarium water. The 0.18 is likely just that coming back off. It is too late to test if the rock came with PO4.

Can you just add some GFO to lower the PO4?

 

[Icedog]

By now the rock would have adsorbed PO4 from the aquarium water. The 0.18 is likely just that coming back off. It is too late to test if the rock came with PO4.

Can you just add some GFO to lower the PO4?

Tks for your response, and I understand where you're coming from. Have the GFO on order and should be arriving soon. Will definitely put some of the GFO in the sump, but would it be also worthwhile to put some in the bowl of salt water with the rock in question? Maybe to pull some phophate off of it so that I can re-enter it into the DT?

 

[Randy Holmes-Farley Verified Community Expert]

Tks for your response, and I understand where you're coming from. Have the GFO on order and should be arriving soon. Will definitely put some of the GFO in the sump, but would it be also worthwhile to put some in the bowl of salt water with the rock in question? Maybe to pull some phophate off of it so that I can re-enter it into the DT?

That's a fine plan, but is not necessarily preferable to doing it in the tank (unless you treat with lanthanum, where the bowl is better, IMO). Pour off any old water first, and add fresh. Might as well dump that phosphate.

 

[Icedog]

That's a fine plan, but is not necessarily preferable to doing it in the tank (unless you treat with lanthanum, where the bowl is better, IMO). Pour off any old water first, and add fresh. Might as well dump that phosphate.

Tks for your input, Randy. Will put fresh salt water in the isolated rock bowl and let it sit until the GFO gets here. Then add the rock to the DT along with the GFO to the sump.

I'm a bit afraid of trying the lanthanum, but will do that next if the GFO doesn't help.

 

[Randy Holmes-Farley Verified Community Expert]

Sounds good.

Happy Reefing.

 

[metalle]

I've been battling high phosphates (and resultant alga) for three months now and have been unable to decipher the cause of such. On Saturday I do a weekly 10% water change, vacuuming the gravel and blowing off the rocks, yet my phosphates are still at 0.3. Yesterday (Wednesday, mid-week) I also did a 15% water change while vacuuming out the sump - thought there might be some detritus in there that is causing the problem. Yet today my phosphates are still at 0.3!

I've been feeding the same amount of the same frozen food for the past two years, so I don't think that's the issue. The only other variable I can think of is a small piece of rock I had placed in the tank a few months ago. So I'm thinking that maybe it's leaching phosphates into the tank???

So I'm considering testing the rock for phosphate leaching:

1. Put some newly mixed salt water in a bucket and test it for phosphates (with Hanna ULP Checker).

2. Put the rock in question in the bucket of salt water, wait 5-7 days, and test it again for phosphate (again, with Hanna ULP Checkeer).

Does this make sense? I know there are a myriad of ways to lower the phosphate, but I'm really trying to find out what the source of the high phosphate levels might be!

If you can weigh the rock and water… concentration can vary over time and you can get a leach rate.