Phosphate at 0.10 Is this Ok

[markaren]

i have a 76g/40 sump.

small phosban reactor with BRS GFO staying level at 0.10

Phosphate parameter used to be 2.50 before the reactor. The reactor has been in 1 week.
The tank has only live rock and 4 fish (small, 2 ocellaris, sand sifter, small baby blue tang...no corals yet.

[tkeracer619]

It's fine but for corals you want .03 or less. It will take time as phosphate will leach out of the rock for some time.

[markaren]

Thank you. This is driving me nuts. My RODI is .00 I could not figure where it was coming from. I have time then. I just did not want to use a chemical or go larger on a reactor yet.

[thegrun]

The phosphate may be leaching out of your rock or simply be in your fish and/or coral food. When you first start using GFO it is not unusual to need to replace the GFO weekly until it drops to nearly zero at which point it should start to last a few weeks between replacements.

[psteeleb]

I agree with the other guys - 0.03 is what you want to target for corals. Many corals will suffer and die off as levels reach 0.10. I found that my GFO will last sevral months once a desirable level is reached but every tank is different. I for one have a lot of live rock thus lots of space for aerobic bacteria.

[markaren]

I have a goal to introduce coral (perhaps LPS) at my one year mark and I know this will not happen if I can not maintain water properly for at least a month. i have not bought a calcium reactor yet, but know what it is and have been reading on how to use if dosing is not an option. just learning and thanking you all for your time and reading and reading...

[sirreal63]

Measure the PO4 of the water exiting the reactor. With it as high as it was, you may have exhausted the GFO already.

[markaren]

Originally Posted by sirreal63

Measure the PO4 of the water exiting the reactor. With it as high as it was, you may have exhausted the GFO already.

Hmmm...thank you. Coming right up. 4 days after the GFO it read zero on a Hanna, But I thought it was just a fluke. (accurate variance)

[markaren]

Bingo...comes out at 0.10! I have never done this change yet. do I just take cylinder and empty/refill/ start up and purge exiting dust till clear into pale and whala...?

[Kies1]

Yes just like the first time except emptying reactor of old and putting in new. If you have filters/sponges in it rinse with RO/DI first.

[markaren]

I do not know if the GFO works better after a day or longer...but...it is coming out at 0.02.

Thank you Sirreal63 for such a simple and yet obvious check. I love this forum for these kind of reasons. I am logical but sometimes miss the obvious. I thought the GFO would work for longer. I believe this reactor is a bit small and I should consider the longer lasting GFO.

[sirreal63]

It can exhaust quickly when po4 is high but once the levels are more normal the GFO will last longer.

[Alex T.]

I do what sirreal does (as do many) to know when to change it out. Once my tank reaches .04, it's about a week before my display and reactor match readings around .05. When they match, your GFO is exhausted and will no longer bind phosphate. I actually shoot for .02 - .05. Every time my po4 measures "undetectable" my SPS don't look very good...more pale.

[KCombs]

Originally Posted by Alex T.

I do what sirreal does (as do many) to know when to change it out. Once my tank reaches .04, it's about a week before my display and reactor match readings around .05. When they match, your GFO is exhausted and will no longer bind phosphate. I actually shoot for .02 - .05. Every time my po4 measures "undetectable" my SPS don't look very good...more pale.

I was about to post something similar....but didn't want to dispute the others who have the target at .03 (I believe their testimonial)

...so I'm hardly disputing that target, but I personally had issues when I got much below .05

not sure why exactly, but my corals look better when I have active algae growth on the glass (at around .06)

...again, not disputing, but simply adding more "plots" to the data

[markaren]

This is the basis of my original question.I know I am getting close to 0.00 and have pretty much had no life outside of work family and reading studying here. This is not a surprise , I just am not sure what to worry about at what number. I am going for 0.02 for sure to begin with and will keep trying to find others likes and dislikes.

This is very good information, knowing 0.00 is not the Holey Grail for everyone.