GFO and controlling phosphates

[SPR1968]

I am intrigued by this statement. Do you mean that phosphates that were absorbed by the gfo will be released back into the water if the gfo isn't replaced, or at least the old is removed?

As for dinos when I first started my current tank I was stupidly under the impression that 0 nitrates and phosphates were best. My nitrates were always 0 and I started gfo in a reactor to where my phosphates were 0 as well. Not surprisingly, looking back at it, I couldn't keep a coral alive and I ended up with a Dino problem. Once I removed the gfo my phosphates naturally settled around .05 (until recently) and I started dosing nitrates to get them between 2-5.

I don't know if accidentally over using gfo and dropping phosphates to 0 would cause another Dino outbreak, but it's a risk I'd rather avoid. Honestly as I am to some degree chasing numbers on my phosphates my corals are looking better than they ever have. To be fair though I've also had a few equipment changes in my tank including more powerheads and new lights around around same time that I saw elevated numbers.

Basically if you don’t change the GFO and it’s spent, it won’t absorb any more phosphate so anything leaching from the rockwork or being added from food etc., will cause phosphate to rise.

Dino’s are often as a result of long periods of sterile water, in particular zero nitrate. They can survive when other types of organisms can’t and hence the potential for problems with them

When I set my large tank up I didn’t turn the skimmer on for 2-3 months for this exact reason until nitrate hit around 5-10 to avoid this sort of issue. And it worked.

In my opinion and as a general guide, a good basic target is nitrate at 10 and phosphate at less than 0.03 for new systems. Once established I don’t mind if my nitrate goes much higher (25+ and corals glow with life at those levels or even higher) because it’s coral food, but phosphate is always kept down. You can study the science here if you wish from one of the experts

http://reefkeeping.com/issues/2006-09/rhf/

 

[X-37B]

Basically if you don’t change the GFO and it’s spent, it won’t absorb any more phosphate so anything leaching from the rockwork or being added from food etc., will cause phosphate to rise.

Dino’s are often as a result of long periods of sterile water, in particular zero nitrate. They can survive when other types of organisms can’t and hence the potential for problems with them

When I set my large tank up I didn’t turn the skimmer on for 2-3 months for this exact reason until nitrate hit around 5-10 to avoid this sort of issue. And it worked.

In my opinion and as a general guide, a good basic target is nitrate at 10 and phosphate at less than 0.03 for new systems. Once established I don’t mind if my nitrate goes much higher (25+ and corals glow with life at those levels or even higher) because it’s coral food, but phosphate is always kept down. You can study the science here if you wish from one of the experts

http://reefkeeping.com/issues/2006-09/rhf/

Ineresting no3 levels.
My system is 95% sps. I keep no3 at <5 and po4 <0.1. Higher po4 and no3 equals less color in my system but corals still thrive.
I also feed heavy and practice heavy in/out.
Any no3 or po4 levels that are measured in any system are what your export system is not removing.

 

[SPR1968]

Ineresting no3 levels.
My system is 95% sps. I keep no3 at <5 and po4 <0.1. Higher po4 and no3 equals less color in my system but corals still thrive.
I also feed heavy and practice heavy in/out.
Any no3 or po4 levels that are measured in any system are what your export system is not removing.

Who knows but higher nitrate is not an issue to me. The only issue is phosphate.

I’ve had nitrates of 50+ in my Red Sea S650 ‘frag tank’ with no issues other than glowing corals. BUT it’s nearly 6 years old.

 

[Gtinnel]

My goal is nitrates at around 10 and phosphates around .1. I used to try to maintain lower levels but I've been happier with the tank when closer to these values.

I always find it amazing how different people and tanks do best at different values. You would think there would be some perfect value that works best for everyone, but that isn't how it works at all.

 

[dferrant]

Careful with GFO
dropping PO4 too quickly can cause big issues
I suffered a wipe out in an SPS tank this way
Do it gradually and start with a little

 

[ScottB]

My goal is nitrates at around 10 and phosphates around .1. I used to try to maintain lower levels but I've been happier with the tank when closer to these values.

I always find it amazing how different people and tanks do best at different values. You would think there would be some perfect value that works best for everyone, but that isn't how it works at all.

I believe the common thread running through healthy systems with very low residual nutrient levels is what @SPR1968 said:

Heavy in / heavy out. At least once the system biome has built up. I try to feed 4 times a day with a pretty big fish load.

 

[Gtinnel]

Careful with GFO
dropping PO4 too quickly can cause big issues
I suffered a wipe out in an SPS tank this way
Do it gradually and start with a little

Other than bottoming out that is my other concern with using gfo. Adding even a small amount of gfo to my tank led to it quickly dropping phosphates more than I cared for.

 

[Gtinnel]

Basically if you don’t change the GFO and it’s spent, it won’t absorb any more phosphate so anything leaching from the rockwork or being added from food etc., will cause phosphate to rise.

Right I understand that. I misunderstood your previous post to say that after absorbing the phosphate it can actually leach back into the water from depleted media, which didn't sound right to me.

 

[ScottB]

Other than bottoming out that is my other concern with using gfo. Adding even a small amount of gfo to my tank led to it quickly dropping phosphates more than I cared for.

I find it easier to manage PO4 with a lanthanum chloride solution like Elimi Phos. Takes out some of the guess work.

When my PO4 gets around .15 I just add 9ml to my overflow and when I test next week it will be around .09.

 

[Gtinnel]

I find it easier to manage PO4 with a lanthanum chloride solution like Elimi Phos. Takes out some of the guess work.

When my PO4 gets around .15 I just add 9ml to my overflow and when I test next week it will be around .09.

I know of lanthanum chloride but I honestly dont know much about it. But I will definitely look into it if I am unable to maintain my desired levels with my fuge and skimming.