Help with phosphates

[rishma]

Is there maybe reason to believe my rocks are leaching phosphate?

Rock and sand binds or releases phosphate to an equilibrium with the water. Your GFo experience is normal. You strip it out of the water, then stop GFO, the rocks release bound phosphate and it goes back up.

Randy’s suggestion to use a very small amount of GFO has worked for me. The whole process slows down, you don’t have to turn on/off the GFO, and you mitigate the phosphate yo-yo.

Start with a small amount..maybe half what you were using before, then monitor phosphate. If it’s going down too fast (as in headed below your target) remove some of the GFO. Of its going up, add some GFO. I like to delay whole change outs of GFO as long as I can because fresh GFO starts the process over again at a higher rate.

 

[reefernc02]

How big was your tank again mine was 850$ but trust me it is a big headache relief and personally I can’t put a price on stability.I believe the smaller units are way cheaper

 

[reefernc02]

Also I had someone local to me 3d print legs for it as it drains from the bottom so it sits in one of the sump compartments

 

[bluecheese]

Rock and sand binds or releases phosphate to an equilibrium with the water. Your GFo experience is normal. You strip it out of the water, then stop GFO, the rocks release bound phosphate and it goes back up.

Randy’s suggestion to use a very small amount of GFO has worked for me. The whole process slows down, you don’t have to turn on/off the GFO, and you mitigate the phosphate yo-yo.

Start with a small amount..maybe half what you were using before, then monitor phosphate. If it’s going down too fast (as in headed below your target) remove some of the GFO. Of its going up, add some GFO. I like to delay whole change outs of GFO as long as I can because fresh GFO starts the process over again at a higher rate.

That makes a lot of sense.

I was only using 1/2 cup for a 125 gallon tank. Doesn't seem like much, but it did drop the phosphates significantly. It's the High Capacity GFO from BRS. Stuff isn't cheap. I may just get a tub of the regular stuff from my LFS and let it ride.

 

[bluecheese]

How big was your tank again mine was 850$ but trust me it is a big headache relief and personally I can’t put a price on stability.I believe the smaller units are way cheaper

125 gallon. But total water volume including the sump is ~115 gallons.

 

[rishma]

That makes a lot of sense.

I was only using 1/2 cup for a 125 gallon tank. Doesn't seem like much, but it did drop the phosphates significantly. It's the High Capacity GFO from BRS. Stuff isn't cheap. I may just get a tub of the regular stuff from my LFS and let it ride.

Try 1/4 cup?

One more thought, you can monitor how the GFO is working by testing the reactor outlet water. When outlet = inlet phospate, it’s all done.

 

[bluecheese]

Try 1/4 cup?

One more thought, you can monitor how the GFO is working by testing the reactor outlet water. When outlet = inlet phospate, it’s all done.

I'll try that. Thanks.

 

[backbayreef]

I've personally found GFO to be a pain inside a reactor. Therefore, I've switched to LC-based dosing (Brightwell Phosphat-E) hooked to a doser; at 6mls/day keeps PO4 stable at 0.2'ish* on a 450gal system with 30 fish. It's super simple to dial in -- increase/decrease mls/day to maintain at a certain level. Prior to this, I was using PhosphateRx but it's too much work dosing manually.

Some people reported issues with tangs but I've been lucky so far (the last 7 years) by dosing into filter floss or skimmer neck. Recently, I've been dosing into a refugium before the skimmer chamber.

*I personally want to keep PO4 at that level since my nitrate is still high. Once nitrate is down, I should be able to keep PO4 under 0.10 without any issues.

 

[bluecheese]

I've personally found GFO to be a pain inside a reactor. Therefore, I've switched to LC-based dosing (Brightwell Phosphat-E) hooked to a doser; at 6mls/day keeps PO4 stable at 0.2'ish* on a 450gal system with 30 fish. It's super simple to dial in -- increase/decrease mls/day to maintain at a certain level. Prior to this, I was using PhosphateRx but it's too much work dosing manually.

Some people reported issues with tangs but I've been lucky so far (the last 7 years) by dosing into filter floss or skimmer neck. Recently, I've been dosing into a refugium before the skimmer chamber.

*I personally want to keep PO4 at that level since my nitrate is still high. Once nitrate is down, I should be able to keep PO4 under 0.10 without any issues.

I looked at that product, but the horror stories I read about fish deaths pushed me towards GFO instead.

 

[reefernc02]

How big was your tank again mine was 850$ but trust me it is a big headache relief and personally I can’t put a price on stability.I believe the smaller units are way cheaper

125 gallon. But total water volume including the sump is ~115 gallons.

Oh yeah you could definitely use one of the smaller models

 

[bluecheese]

Oh yeah you could definitely use one of the smaller models

Any suggestions? BRS only seems to have the Adaptive Reef algae scrubbers

 

[reefernc02]

Let me talk to Josh and see what he recommends

 

[backbayreef]

I looked at that product, but the horror stories I read about fish deaths pushed me towards GFO instead.

Certainly - it's still unexplainable and my personal experience should not constitute as facts. With everything, there is an element of risk involved and ymmv. Good luck with your phosphate challenges...

 

[WillpoleReefers]

125 gallon tank with around 115 gallons of total water volume. Mixed reef.

Tank has been up and running since August of 2021.

I had surgery back in April. So I was not able to stay on top of the tank for 2 months while I recovered. I still did my weekly water changes and changed the filter socks. But I was not able to syphon out the sand like I normally would.

When I tested my water at the end of May on a Hannah checker, it came back as 1.94. Thinking I did something wrong, I checked again, and it came back at 1.84.

I started using GFO in a reactor at the beginning of June. I tested daily, and on June 18, the phosphates tested at 0.05.

I pulled the GFO, and the next day phosphates tested at 0.21. The day after that it was at 0.24.

On June 23 phosphates were at 0.39. So I started using GFO again.

The phosphate level slowly dropped to where I tested at 0.08 yesterday.

This morning it tested at 0.15 with GFO still in the reactor.

I test at the same time in the morning before the fish are fed. I feed sparingly. Change the filter socks out twice a week. I have a protein skimmer that is dialed in and produces a dark green skimmate that I clean out weekly.

Before surgery I would do weekly 10% water changes while syphoning out the sand. I have started doing the 10% water changes which includes syphoning out the sand since recovering.

I feel like my phosphate levels are like a bouncing ball, and I'm kind of sick of chasing numbers. I just want to keep it below 0.1 without having to constantly test and add/remove GFO based on test results.

Any ideas what might be going on?

I have a 10 inch RO filter canister filled with GFO. I feed through it using a constant flow rated peristaltic pump for accurate flow tuning. Seems to work perfectly, you can tune the phos to exactly what you want , about 65ml /min in use for a 1200L system currently. The canister of GFO lasts ages, can change it every two months or so

 

[bluecheese]

Any thoughts on Phosguard?

 

[Randy Holmes-Farley Verified Community Expert]

Any thoughts on Phosguard?

I’m not a fan due to aluminum concern, but it does work.

 

[BryanM]

I have. I need to see how much they cost. But space is at a premium under the tank. It sits on a custom made bookshelf. There is just enough room under there for the plumbing, sump, ATO bucket, and a dosing container.

Santa Monica sells ATSes that float in the sump, a potential option. I use one and love it, takes about 6 weeks to really start growing turf algae.

 

[KrisReef]

125 gallon tank with around 115 gallons of total water volume. Mixed reef.

Tank has been up and running since August of 2021.

I had surgery back in April. So I was not able to stay on top of the tank for 2 months while I recovered. I still did my weekly water changes and changed the filter socks. But I was not able to syphon out the sand like I normally would.

When I tested my water at the end of May on a Hannah checker, it came back as 1.94. Thinking I did something wrong, I checked again, and it came back at 1.84.

I started using GFO in a reactor at the beginning of June. I tested daily, and on June 18, the phosphates tested at 0.05.

I pulled the GFO, and the next day phosphates tested at 0.21. The day after that it was at 0.24.

On June 23 phosphates were at 0.39. So I started using GFO again.

The phosphate level slowly dropped to where I tested at 0.08 yesterday.

This morning it tested at 0.15 with GFO still in the reactor.

I test at the same time in the morning before the fish are fed. I feed sparingly. Change the filter socks out twice a week. I have a protein skimmer that is dialed in and produces a dark green skimmate that I clean out weekly.

Before surgery I would do weekly 10% water changes while syphoning out the sand. I have started doing the 10% water changes which includes syphoning out the sand since recovering.

I feel like my phosphate levels are like a bouncing ball, and I'm kind of sick of chasing numbers. I just want to keep it below 0.1 without having to constantly test and add/remove GFO based on test results.

Any ideas what might be going on?

Yeah, You got P attached to the substrate. When GFO is removing it from the water column it will test low. When you quit GFO the substrate is releasing the P into the water and the levels you can test creep up.

The system is in an equilibrium state with adhered P sticking and unsticking from the substrate moving into the water when those levels are reduced from GFO adsorbtion- reaction. You have to keep removing it from the substrate and when that is mostly gone water levels will go low BUT will not bounce back.

P is totally like a stalker relationship. Until you get rid of it from your substrate it will keep creeping up on you.

 

[bluecheese]

Yeah, You got P attached to the substrate. When GFO is removing it from the water column it will test low. When you quit GFO the substrate is releasing the P into the water and the levels you can test creep up.

The system is in an equilibrium state with adhered P sticking and unsticking from the substrate moving into the water when those levels are reduced from GFO adsorbtion- reaction. You have to keep removing it from the substrate and when that is mostly gone water levels will go low BUT will not bounce back.

P is totally like a stalker relationship. Until you get rid of it from your substrate it will keep creeping up on you.

Now a stalker relationship I’m familiar with. Been there. Don’t want to do it again.

How does one remove phosphate from the substrate? I’m already siphoning it weekly.

 

[KrisReef]

Now a stalker relationship I’m familiar with. Been there. Don’t want to do it again.

How does one remove phosphate from the substrate? I’m already siphoning it weekly.

It's a slow process keeping the water levels low, (GFO and lanthanum chloride) for a period of time so that the attached P naturally dissociates into the water from off the rocks (to replace P lost from the water column), until it's low in both places.