How to use a GFO reactor

[Sordfish]

So based on feedback to my recent posts (thanks to everyone who commented ) I bought a Phosban GFO reactor and set it up. It works well but it seems like a ton of work to use.

I put in 2” of rowaphos and turn on the pump to gently bubble through. I then go through the following cycle over and over:

1- turn on the reactor for 2 to 3 days until the phosphates go down to 0.03 or so. Any longer and I expect my phosphates would go to 0.
2 - turn off the reactor the next 2 to three days until the phosphates are at 0.14 or so.
3- turn the reactor back on for 2-3 days. So on and so forth.

Of course this means I am testing phosphates every day and turning the reactor on or off every 2 to 3 days.

Is this how people do it? It seems like a ton of work that will never end. What am I doing wrong?

 

[Salty_Northerner]

I think the way people do it is by only adding a small amount so the phosphate doesn't bottom out. But I'm sure if I'm wrong I'll be corrected.

Also that's a big swing you got going on. I'm sure if you remove some media you'll be able to let it run all the time and test alot less and hold whatever specific po4 you want.

 

[DivingTheWorld]

How old is your tank? IMO GFO really shouldn’t be attempted until a tank is seasoned, 1-1.5 years.

But as to your question of “how” to run. Use one of the various calculators to determine how much to use for your size tank. Start with a half dose and run like that for several months while monitoring your phosphate. You’ll want a good tester like a Hanna ULR Phosphorus tester.

In theory, you should be able to run it 24/7 and swap it out every month or so. If it’s reducing your phosphates to 0, you’re using too much or your tank doesn’t really need it.

 

[Salty_Northerner]

I also use a media reactor but just for carbon. I'll use seachem phosguard and put a couple table spoons into a small filter bag and toss it into a filter sock and that seems to work for me and keep po4 in the .03-.07 range

 

[Sordfish]

I also use a media reactor but just for carbon. I'll use seachem phosguard and put a couple table spoons into a small filter bag and toss it into a filter sock and that seems to work for me and keep po4 in the .03-.07 range

I initially tried the bags but no matter how much I put in, it’d be exhausted in a couple of days (literally) and phosphates would creep up while the bag was in there. One person suggested that there was biofilm forming on the GFO and so tumbling in the reactor would prevent that which is why I bought the reactor.

 

[Sordfish]

I think the way people do it is by only adding a small amount so the phosphate doesn't bottom out. But I'm sure if I'm wrong I'll be corrected.

Also that's a big swing you got going on. I'm sure if you remove some media you'll be able to let it run all the time and test alot less and hold whatever specific po4 you want.

I agree those are big swings and am not sure why. I have just cut back my fish feeding by a 1/3. I don’t think I can cut back any more without stressing my chromis. I also stopped all coral feedings a month ago. I’ll see if that helps.

 

[Miami Reef]

I initially tried the bags but no matter how much I put in, it’d be exhausted in a couple of days (literally) and phosphates would creep up while the bag was in there. One person suggested that there was biofilm forming on the GFO and so tumbling in the reactor would prevent that which is why I bought the reactor.

You can use GFO for any age tank.

Just use 1tsp for now, and leave it until the phosphates begin to creep up above your preferred range.

Remember, most tanks should have PO4 from 0.02-0.10ppm. Above is better than below that range.

 

[Sordfish]

How old is your tank? IMO GFO really shouldn’t be attempted until a tank is seasoned, 1-1.5 years.

But as to your question of “how” to run. Use one of the various calculators to determine how much to use for your size tank. Start with a half dose and run like that for several months while monitoring your phosphate. You’ll want a good tester like a Hanna ULR Phosphorus tester.

In theory, you should be able to run it 24/7 and swap it out every month or so. If it’s reducing your phosphates to 0, you’re using too much or your tank doesn’t really need it.

The tank is 8 months old. It did get some of the rocks from my previous nano tank - but it was an upgrade from 25g to 100g so there was lots of new dry rock as well. Also, I do use the Hanna ULR tester - I love them.

I did not know a calculator was a thing. Thanks. I’ll reload the reactor with the right amount (1/2 as you suggested) and see if that works.

How often should I they the phosphates once I reload the reactor? Once a day is quite onerous and getting costly.

 

[DivingTheWorld]

The tank is 8 months old. It did get some of the rocks from my previous nano tank - but it was an upgrade from 25g to 100g so there was lots of new dry rock as well. Also, I do use the Hanna ULR tester - I love them.

I did not know a calculator was a thing. Thanks. I’ll reload the reactor with the right amount (1/2 as you suggested) and see if that works.

How often should I they the phosphates once I reload the reactor? Once a day is quite onerous and getting costly.

Adjust the amount you’re using until it lasts 3-4 weeks. It will be trial and error because every tank is different. What you don’t want are large fluctuations up or down in phosphates. IMO corals prefer high phosphate over large swings of phosphate.

 

[Aquavaj]

You can put a ball valve inline to control flow. Less water going through means less phosphate being pulled out.

 

[Pistondog]

So based on feedback to my recent posts (thanks to everyone who commented ) I bought a Phosban GFO reactor and set it up. It works well but it seems like a ton of work to use.

I put in 2” of rowaphos and turn on the pump to gently bubble through. I then go through the following cycle over and over:

1- turn on the reactor for 2 to 3 days until the phosphates go down to 0.03 or so. Any longer and I expect my phosphates would go to 0.
2 - turn off the reactor the next 2 to three days until the phosphates are at 0.14 or so.
3- turn the reactor back on for 2-3 days. So on and so forth.

Of course this means I am testing phosphates every day and turning the reactor on or off every 2 to 3 days.

Is this how people do it? It seems like a ton of work that will never end. What am I doing wrong?

I dont think any of the po4 levels you mention are worth acting on.
Sound like if you ran the gfo reactor every other day or 6 hours on then 6 hours off, that might work, or as others have suggested, run less gfo.
Not a good idea to leave a reactor off a few days without flushing.

 

[Sordfish]

Thanks. These are all good ideas. I’ll work with the amount of gfo, adjust the flow and use the time on to dial it in. I do agree these wild swings in phosphate is not good. However, when unchecked by gfo they had risen to 0.34, hence the gfo. I’ll also have to figure out the cause for the sudden explosion in phosphate. Up until 4 weeks ago I was more worried about bottoming out.

 

[gbroadbridge]

So based on feedback to my recent posts (thanks to everyone who commented ) I bought a Phosban GFO reactor and set it up. It works well but it seems like a ton of work to use.

I put in 2” of rowaphos and turn on the pump to gently bubble through. I then go through the following cycle over and over:

1- turn on the reactor for 2 to 3 days until the phosphates go down to 0.03 or so. Any longer and I expect my phosphates would go to 0.
2 - turn off the reactor the next 2 to three days until the phosphates are at 0.14 or so.
3- turn the reactor back on for 2-3 days. So on and so forth.

Of course this means I am testing phosphates every day and turning the reactor on or off every 2 to 3 days.

Is this how people do it? It seems like a ton of work that will never end. What am I doing wrong?

You need to find the appropriate amount of whatever GFO you're using.

I use about 150g for my 75g and it lasts 6 weeks keeping at around 0.05.
When it starts to creep up you change, but for me it's almost always 6 weeks.

 

[EeyoreIsMySpiritAnimal]

Thanks. These are all good ideas. I’ll work with the amount of gfo, adjust the flow and use the time on to dial it in. I do agree these wild swings in phosphate is not good. However, when unchecked by gfo they had risen to 0.34, hence the gfo. I’ll also have to figure out the cause for the sudden explosion in phosphate. Up until 4 weeks ago I was more worried about bottoming out.

There's nothing wrong with 0.34 either, although I understand that you don't want it to keep rising forever... Since your tank seems to be determined to have a higher level, why not try keeping it between 0.3 and 0.5?

 

[Randy Holmes-Farley]

I agree that using less is appropriate.

 

[Sordfish]

You need to find the appropriate amount of whatever GFO you're using.

I use about 150g for my 75g and it lasts 6 weeks keeping at around 0.05.
When it starts to creep up you change, but for me it's almost always 6 weeks.

Thanks for the number. Appreciate it.

 

[Sordfish]

There's nothing wrong with 0.34 either, although I understand that you don't want it to keep rising forever... Since your tank seems to be determined to have a higher level, why not try keeping it between 0.3 and 0.5?

Thanks. I have to say, this is different than what I have repeatedly been told - to keep it around .1 or below or else the acros would start showing issues. Is your experience different? So far mine are doing ok but I am worried about the swings