When to run GFO?

[Heavymman]

I have been struggling to slowly raise my nutrients since I started with dry rock. I was able to raise my nitrates to ~1.5ppm and my phosphate has been climbing from .05 - 1.1 this past week. I was feeding twice a day with an auto feeder (mixed pellets w/ reef chili). I ceased feeding w/ the autofeeder and back to feeding mixed frozen mysis once a day .

I am a firm believer that everything we do needs to be slow and balanced so we don’t throw everything off. I am just curious, when does one make the decision to start running GFO?

 

[Hitman]

I run BRS Hi Cap GFO 24/7 the first year of every tank I set up. Then I let the tank control it from there. No matter how much or what I feed my PO4 stays at 0.02ppm right where I want it. If you have 1.1 then GFO will be pretty late to the party but better late then never.

 

[Jason Cohn]

I only use a small amount of GFO and do it with Chemipure elite bags (I use less than suggested for my tank size). It’s kept my nutrients at a reasonable level to sustain a large variety mixed reef.

 

[SPR1968]

If your at 0.11 (or even 1.1 you mention) it’s worth looking into using GFO if that’s the route your taking.

I run rhowaphos 24/7 in a reactor and change it around every 3 weeks to keep phosphate locked down

I’ve said this before, but adding rhowaphos is the best single thing I ever did with my system. I have no algae or any other issues.

Just remember it needs changing when spent, (when phosphate starts to rise again) otherwise it won’t work properly

I’m at a point now we’re i only test phosphate every few weeks these days

 

[Hemmdog]

I only use a small amount of GFO and do it with Chemipure elite bags (I use less than suggested for my tank size). It’s kept my nutrients at a reasonable level to sustain a large variety mixed reef.

+1

 

[Heavymman]

I’m going to change the water Saturday, I will follow up with testing the phosphate on Sunday. I can always run a reactor if it’s still high, I was just concerned if I start running GFO it would decrease it to 0 and I would be causing more harm than good

 

[dantimdad]

I used to run GFO. I read more negative than positive and my experience was to the negative as well.

This is not to make a blanket statement and say don't run it!

All I am saying is I prefer the slower and more natural method of running chaeto. If I even have a phosphate issue at all. Most of the time I don't. Usually it's low nutrients are the issue.

This tank was started with dead rock just like my last one and I probably won't do that again. At least not all dead anyway. I have had more algae issues in the last two tanks than all my previous tanks combined. (except my first tank 30+ years ago but we won't go into that one!)

 

[Heavymman]

I used to run GFO. I read more negative than positive and my experience was to the negative as well.

This is not to make a blanket statement and say don't run it!

All I am saying is I prefer the slower and more natural method of running chaeto. If I even have a phosphate issue at all. Most of the time I don't. Usually it's low nutrients are the issue.

This tank was started with dead rock just like my last one and I probably won't do that again. At least not all dead anyway. I have had more algae issues in the last two tanks than all my previous tanks combined. (except my first tank 30+ years ago but we won't go into that one!)

I think I’m just going to do the same, I am most likely over thinking and I prefer the slow and steady which is starting to be more challenging but the reason I enjoy the hobby in the first place. Thanks for your insight!

 

[Dkeller_nc]

There's no particular reason not to run GFO or dose LaCl2 as a temporary counter measure to an elevated phosphate concentration (as opposed to running it continuously). But that's assuming that your first post wasn't a typo, and you truly have phosphate at 1.1 ppm, and not 110 ppb (which is fine).

 

[Heavymman]

There's no particular reason not to run GFO or dose LaCl2 as a temporary counter measure to an elevated phosphate concentration (as opposed to running it continuously). But that's assuming that your first post wasn't a typo, and you truly have phosphate at 1.1 ppm, and not 110 ppb (which is fine).

Hanna ULR PPM, 1.1 ppm from .05 in a week. So 1.1 isn’t ridiculously crazy where I NEED to take action right away, right? Interesting enough, my green Slimer is also showing better color right now, go figure

 

[Dkeller_nc]

That would be a bit higher than most of us run, but yeah, the danger is that you'd respond too strongly and strip most all of the phosphate from your water, which might have bad effects on your corals, especially is your nitrate is low. Nevertheless, I'd be thinking about export methods to prevent an serious algae outbreak.

 

[Heavymman]

That would be a bit higher than most of us run, but yeah, the danger is that you'd respond too strongly and strip most all of the phosphate from your water, which might have bad effects on your corals, especially is your nitrate is low. Nevertheless, I'd be thinking about export methods to prevent an serious algae outbreak.

.01 ppm. This doesn’t make sense, I stopped the auto feeder and was just feeding mysis once a day, could my tank really be able to swing that much? I’m only skimming and running a filter sock (I replace the sock every 2-3 days)

 

[Dkeller_nc]

No, it definitely can't. A swing like that would require massive water changes (near 100%), or running some kind of phosphate removal technique, such as GFO or lanthanum chloride.

If you're new to the Hanna checkers, there's some techniques that you must use to get an accurate result. Besides keeping the vials clean, you must get an accurate measure of your tank water into the vial (I'd use a syringe to avoid getting any on the outside of the vial), the outside of the vial needs to be clean as a whistle when you put it into the reader at the "C1" point to press the button and zero the meter. Always orient the vial so the "10mL" is facing you. Add the reagent - all of it. Don't use Hanna's suggested technique of artfully cutting the packet; either cut a small square of wax paper, put a crease in it, pour the reagent out onto the wax paper, and use the crease as a funnel to get the reagent into the vial, or purchase a micro-funnel off of Amazon. Cap the vial, shake it for 1:30 - 2 min (time it), all the while holding the vial between your thumb and index finger from the top and the bottom - do not touch the side of the vial. Put the vial back in the reader, and hold down the "read" button until you start the 3 minute timer.

If you follow the above to the letter, you should get an accurate (and repeatable) result. If not, you've encountered a bad batch of Hanna reagents, which does happen from time to time.

 

[Heavymman]

No, it definitely can't. A swing like that would require massive water changes (near 100%), or running some kind of phosphate removal technique, such as GFO or lanthanum chloride.

If you're new to the Hanna checkers, there's some techniques that you must use to get an accurate result. Besides keeping the vials clean, you must get an accurate measure of your tank water into the vial (I'd use a syringe to avoid getting any on the outside of the vial), the outside of the vial needs to be clean as a whistle when you put it into the reader at the "C1" point to press the button and zero the meter. Always orient the vial so the "10mL" is facing you. Add the reagent - all of it. Don't use Hanna's suggested technique of artfully cutting the packet; either cut a small square of wax paper, put a crease in it, pour the reagent out onto the wax paper, and use the crease as a funnel to get the reagent into the vial, or purchase a micro-funnel off of Amazon. Cap the vial, shake it for 1:30 - 2 min (time it), all the while holding the vial between your thumb and index finger from the top and the bottom - do not touch the side of the vial. Put the vial back in the reader, and hold down the "read" button until you start the 3 minute timer.

If you follow the above to the letter, you should get an accurate (and repeatable) result. If not, you've encountered a bad batch of Hanna reagents, which does happen from time to time.

I’m going to test again right now, I’m pretty used to the Hanna’s (used it almost everyday when fish were in QT with copper). It could have been human error or my part the last time.

My other theory if I can’t rule it out is that I mixed a lot of reef chili with the pellet food in the autofeeder. I fed up to 4 x a day small amounts of pellets through autofeeder but maybe I was overdosing reef chili hence causing a temp rise in phosphates. Only reason I’m thinking this is there was a HUGE bloom of pods almost after a week and a half doing this.

I don’t know, I could be overthinking it and screwed the test up

 

[Heavymman]

.03 ppm , I can’t see the Hanna ULR being more difficult than their Calcium which I use and double check with Red Sea. I’m going to check phosphates with my Red Sea to double check. This leads me to think maybe I mis test on Monday twice, .09 and 1.1....

 

[Heavymman]

Ok, Red Sea confirmed .01 ppm PO4. Either I overfed so much it raised my PO4 that drastically and it came back the quickly (highly unlikely like @Dkeller_nc stated) or I mis tested it on Monday night.

I guess once I do my water change Saturday, I will take a baseline PO4 on Sunday and go back with the auto feeder and test and monitor. I’m trying to find my normal feeding cycle so I keep the tank as stable as possible, please let me know what you all think, thanks for all the help so far!

 

[Dkeller_nc]

I'd guess that if this is a new tank, especially if it's bare-bottom, you're much more likely to have low to undetectable levels of phosphate than really high levels. Though this would also depend on the source of the rock in the tank - dead, mined aragonite or truly live rock.