Fresh GFO making no impact on phosphate levels

[rsach]

This is the reading from the output of the reactor post switching the GFO.

I have been struggling with 0.6 phosphate and 75 nitrate levels for a while, finally decided to try BRS high capacity GFO in addition to Chaeto reactor. Total tank volume is 110g.
I started with 6 Tbsp which is half the recommended dosage, and

tested for 3 days, the levels were still at 0.6. I have tested using Hanna and Salifert. Today I trashed the GFO in the reactor assuming that it might have been exhausted and filled it with fresh 6 Tbsp of GFO, I tested the output of the reactor after switching it and it shows around 0.25 phosphates already, what am I doing wrong

 

[smitten with ocean life]

Following. I have the same problem. Except my nitrates are 48 and phos are .4. When I try to lower it, my corals get grumpy

 

[KrisReef]

I can't tell how much water is going through the reactor but it appears that it is going through one narrow pathway and so most of the GFO isn't contacting the flow so it isn't being treated with the set up.

Channelization of flow through media reduces the filtration process. The same problem can occur in DI resin containers and it has similar results, failure to remove the target ions.

 

[rsach]

I can't tell how much water is going through the reactor but it appears that it is going through one narrow pathway and so most of the GFO isn't contacting the flow so it isn't being treated with the set up.

Channelization of flow through media reduces the filtration process. The same problem can occur in DI resin containers and it has similar results, failure to remove the target ions.

Would you suggest using a bigger reactor or using a media bag?

 

[gbroadbridge]

This is the reading from the output of the reactor post switching the GFO.

I have been struggling with 0.6 phosphate and 75 nitrate levels for a while, finally decided to try BRS high capacity GFO in addition to Chaeto reactor. Total tank volume is 110g.
I started with 6 Tbsp which is half the recommended dosage, and

tested for 3 days, the levels were still at 0.6. I have tested using Hanna and Salifert. Today I trashed the GFO in the reactor assuming that it might have been exhausted and filled it with fresh 6 Tbsp of GFO, I tested the output of the reactor after switching it and it shows around 0.25 phosphates already, what am I doing wrong

How fast is the flow through the reactor?

The GFO should be just lightly tumbling - not crazy, but not sitting still either.

The Salifert test is pretty useless, check it on some freshly made salt water in case it is giving a bad result.

 

[KrisReef]

Would you suggest using a bigger reactor or using a media bag?

I would try to get the reactor working more effectively, since it is already online. Bumping up the flow to get the GFO moving more to prevent channelization would be my first change. If you can get more of the media tumbling and remeasure after it has had time to flush out the reaction chamber.

Mesh bag defeats the purpose of the media reactor, but if you can use one of those in your system, whatever works is good enough.

I gave up on GFO for some of the reasons you are experiencing. I had a difficult time putting it in the tank and being able to control the removal of P in a stable movement. It seemed that different GFO products had different uptake properties, and I did not find them to be consistent enough for my reactor ues. Refilling with new media was always a toss of the dice for me, never sure how low, or close to zero I would land.

I switched to liquid lanthanum chloride remover because dropwise additions were more consistent for me in removal of P. It was easy measure, add a few drops of LC and remeasure, and then calculate how much I needed to add to get to zero, and then only add small fractions of that amount to move towards lower numbers but avoid hitting bottom. I only mention the latter stuff in case you find moving forward with GFO doesn't work for you either? Some people swear by it, not at it. GL.

 

[rsach]

How fast is the flow through the reactor?

The GFO should be just lightly tumbling - not crazy, but not sitting still either.

The Salifert test is pretty useless, check it on some freshly made salt water in case it is giving a bad result.

I posted a video showing the tumbling, not sure if it's working. I don't know what the exact flow it, will try to measure it with a gallon jar. I will also test fresh saltwater in the morning. I did double check with a Hanna tester as well and it showed 0.61 ppm

 

[rsach]

I would try to get the reactor working more effectively, since it is already online. Bumping up the flow to get the GFO moving more to prevent channelization would be my first change. If you can get more of the media tumbling and remeasure after it has had time to flush out the reaction chamber.

Mesh bag defeats the purpose of the media reactor, but if you can use one of those in your system, whatever works is good enough.

I gave up on GFO for some of the reasons you are experiencing. I had a difficult time putting it in the tank and being able to control the removal of P in a stable movement. It seemed that different GFO products had different uptake properties, and I did not find them to be consistent enough for my reactor ues. Refilling with new media was always a toss of the dice for me, never sure how low, or close to zero I would land.

I switched to liquid lanthanum chloride remover because dropwise additions were more consistent for me in removal of P. It was easy measure, add a few drops of LC and remeasure, and then calculate how much I needed to add to get to zero, and then only add small fractions of that amount to move towards lower numbers but avoid hitting bottom. I only mention the latter stuff in case you find moving forward with GFO doesn't work for you either? Some people swear by it, not at it. GL.

I did think about liquid lanthanum chloride as I read that it gave more consistent results as you mentioned, but the only reason I decided not to use or am scared to use it is due to having multiple Tangs in my tank and I have read some horror stories about it affecting Tangs. Did you see any such issues?
I will try to up the flow and test it out again. I am hoping to get some positive results. Thanks for your feedback.

 

[KrisReef]

I did think about liquid lanthanum chloride as I read that it gave more consistent results as you mentioned, but the only reason I decided not to use or am scared to use it is due to having multiple Tangs in my tank and I have read some horror stories about it affecting Tangs. Did you see any such issues?
I will try to up the flow and test it out again. I am hoping to get some positive results. Thanks for your feedback.

I have not had issues with any fishes, but I know that others have posted this possibility. I have also read that some folks use LC inside of a 5 micron sock to collect precipitate. I tried this for a while, not really sure if I captured any of the clouds.
I do think it is wise to be careful, so I added in the sump in front of the skimmer for a while, but eventually after not seeing any reaction from the fish I have added directly to the dt without incidents.

 

[AquaLogic]

The pump you have on your reactor might be too weak, it should be tumbling. Your nitrate levels are awfully high. I don't know that it will hurt anything but could fuel algae growth. How are your nitrates that high with your phoshpates so low? For what reason are you trying to lower your phosphates. .5 isn't all that high. Are you having some kind of problem? If so, what problem are you trying to solve by lowering your phosphates? The ideal ratio of nitrates to phosphates 16:1 according to some theories (The Redfield ratio). Your nitrates are way higher than that. I have to does nitrates because they bottom out. Have you considered how your nutrient import/export strategy is impacting these levels?

 

[rsach]

The pump you have on your reactor might be too weak, it should be tumbling. Your nitrate levels are awfully high. I don't know that it will hurt anything but could fuel algae growth. How are your nitrates that high with your phoshpates so low? For what reason are you trying to lower your phosphates. .5 isn't all that high. Are you having some kind of problem? If so, what problem are you trying to solve by lowering your phosphates? The ideal ratio of nitrates to phosphates 16:1 according to some theories (The Redfield ratio). Your nitrates are way higher than that.

I have a valve on the pump and I can increase the flow, I was worried about keeping it too high therefore I dialed it to where only the top surface of the GFO showed some movement. The main reason I was trying to lower the Phosphates it to be able to keep some gonis, torch and digis. I have a monti cap hammer and satosas are doing fine, but I kept losing torch and digis as they didn't survive. Zoas and mushrooms are doing fine, I don't have any high end corals. I barely have any algae growth, not even on the glass, but that might because I recently dealth with dinos after switching lights and had to use waterglass for treatment. It did kill lots of my corals, and all the coraline algae. The strange thing is that even with dinos, the phostphate and nitrate levels were this high. I have tried biopellets and carbon dosing with not much luck. I am now trying algae reactor to see if it helps in lowering the nitrates, it's been online for a couple of weeks, chaeto is growing, but nitrates are still high.

 

[rsach]

I have not had issues with any fishes, but I know that others have posted this possibility. I have also read that some folks use LC inside of a 5 micron sock to collect precipitate. I tried this for a while, not really sure if I captured any of the clouds.
I do think it is wise to be careful, so I added in the sump in front of the skimmer for a while, but eventually after not seeing any reaction from the fish I have added directly to the dt without incidents.

Thanks for sharing your experience. Were use using a fine filter sock when adding it directly to the DT? I also read that some people added it into the neck of the skimmer.

 

[AquaLogic]

I have a valve on the pump and I can increase the flow, I was worried about keeping it too high therefore I dialed it to where only the top surface of the GFO showed some movement. The main reason I was trying to lower the Phosphates it to be able to keep some gonis, torch and digis. I have a monti cap hammer and satosas are doing fine, but I kept losing torch and digis as they didn't survive. Zoas and mushrooms are doing fine, I don't have any high end corals. I barely have any algae growth, not even on the glass, but that might because I recently dealth with dinos after switching lights and had to use waterglass for treatment. It did kill lots of my corals, and all the coraline algae. The strange thing is that even with dinos, the phostphate and nitrate levels were this high. I have tried biopellets and carbon dosing with not much luck. I am now trying algae reactor to see if it helps in lowering the nitrates, it's been online for a couple of weeks, chaeto is growing, but nitrates are still high.

The whole bed of GFO should tumble gently, if it isn't then the flow is too low. You don't want it going wild, but you want the entire bed gently tumbling.

.6 phosphates shouldn't be killing Euphyllia, but getting them to .1 or below is ideal. The nitrates however are very out of range for LPS, they should be closer to 10, definitely no more than 20ish. You have a nutrient problem altogether, not just a phosphate problem. Are you using RODI water? What are your TDS? Have you tested your water lately for nitrates and phosphates before mixing, and after mixing before adding to your aquarium? If you have a water quality problem going in, it's going to cause all sorts of tank issues.

 

[rsach]

The whole bed of GFO should tumble gently, if it isn't then the flow is too low. You don't want it going wild, but you want the entire bed gently tumbling.

.6 phosphates shouldn't be killing Euphyllia, but getting them to .1 or below is ideal. The nitrates however are very out of range for LPS, they should be closer to 10, definitely no more than 20ish. You have a nutrient problem altogether, not just a phosphate problem. Are you using RODI water? What are your TDS? Have you tested your water lately for nitrates and phosphates before mixing, and after mixing before adding to your aquarium? If you have a water quality problem going in, it's going to cause all sorts of tank issues.

Thanks for the feedback, I will bump up the flow in the morning, hopefully that's the issue. I do use RODI water and the TDS is at 0. I had tested the nitrates level of the RODI water a while back and it was at zero, I will check both nitrates and phosphate levels before and after mixing as you have suggested and report back. Thanks!

 

[AquaLogic]

Thanks for the feedback, I will bump up the flow in the morning, hopefully that's the issue. I do use RODI water and the TDS is at 0. I had tested the nitrates level of the RODI water a while back and it was at zero, I will check both nitrates and phosphate levels before and after mixing as you have suggested and report back. Thanks!

Good luck! I think the mystery to solve right now is where the raised levels of nutrients are coming from, and address that issue. It could be over feeding, over stocking, die off of livestock releasing nutrients etc.

 

[Garf]

Would you suggest using a bigger reactor or using a media bag?

I think it's worth noting that calcium carbonate that is already bound with phosphate can take a long time to release this bound phosphate. Therefore the phosphate will constantly unbind from sand and rock, to reach an equilibrium with the water column. The outcome of this can be a slow and steady reduction of testable phosphate in the water column, which probably isn't a bad thing.

 

[Mr. Mojo Rising]

Good luck! I think the mystery to solve right now is where the raised levels of nutrients are coming from, and address that issue. It could be over feeding, over stocking, die off of livestock releasing nutrients etc.

I agree, I would be trying to find the source of the high nutrients, you must be adding them to the tank somehow.

What kind of filtration equipment are you running on this tank? How many fish do you have and how much do you feed? What kind of food do you feed? Do you feed corals often?

 

[rsach]

I agree, I would be trying to find the source of the high nutrients, you must be adding them to the tank somehow.

What kind of filtration equipment are you running on this tank? How many fish do you have and how much do you feed? What kind of food do you feed? Do you feed corals often?

It's a 50x26x20" tank, with 30 gallon trigger sump, I'm using media cups with filter floss, algae reactor, simplicity 240dc skimmer, have 6 fish (foxface, bristle tooth, yellow, hippo and 2 clown fish). I feed pellets (NLS and do chroma boost mixed) once a day, it's usually consumed within 2-3 mins. I barely feed the corals, but I use coral feast when feeding them.

 

[rsach]

Thanks for the feedback, I will bump up the flow in the morning, hopefully that's the issue. I do use RODI water and the TDS is at 0. I had tested the nitrates level of the RODI water a while back and it was at zero, I will check both nitrates and phosphate levels before and after mixing as you have suggested and report back. Thanks!

I checked the nitrates and phosphates level of my rodi water and fresh saltwater and they are at zero, so at least we can rule these out

 

[Dan_P]

This is the reading from the output of the reactor post switching the GFO.

I have been struggling with 0.6 phosphate and 75 nitrate levels for a while, finally decided to try BRS high capacity GFO in addition to Chaeto reactor. Total tank volume is 110g.
I started with 6 Tbsp which is half the recommended dosage, and

tested for 3 days, the levels were still at 0.6. I have tested using Hanna and Salifert. Today I trashed the GFO in the reactor assuming that it might have been exhausted and filled it with fresh 6 Tbsp of GFO, I tested the output of the reactor after switching it and it shows around 0.25 phosphates already, what am I doing wrong

Sounds like 6 tablespoons is not enough. The recommendation is based on the amount of PO4 in the water. In your situation you are probably dealing with PO4 desorbing from the sand and rocks which can be a large reserve. Increase the amount of phosphate and just keep going. Measuring the reactor output is a good way to tell when the GFO is exhausted.