My Phosphate is .95 ppm!

[bpro32]

Believe it or not, I'm actually celebrating this

3 weeks ago I started testing phosphate because I thought I might be interested in keeping some sps and to my surprise it was at 2.5 ppm! And this was on a Hanna low range which maxes out at 2.5 ppm so I really don't know how high it was. I did a couple 20% water changes right away - I didn't know at the time water changes don't help much to lower phosphates so I was disappointed when, a week later, it was still at 2.5. I did some reading, added a half portion of GFO and fired up my chaeto reactor. Chaeto is growing like crazy (of course it is because, you know, high phosphates and probably high nitrates) and the GFO must be doing it's job.

I have been overfeeding and under skimming so I'm interested to see what phosphates and nitrates look like once those are corrected and the GFO reactor comes offline.

 

[Graffiti Spot]

What are your nitrates at?

 

[bpro32]

What are your nitrates at?

I'm not tracking nitrates yet. I'm upgrading soon and I'll be starting with 80%+ new water so I didn't think current nitrates were very important.

 

[jda]

Do not lower it too quickly or you might make your corals and inverts mad. Lowering P is not an issue, but doing it too fast can be.

Read up on phosphate binding to aragonite and how the aragonite can act like a reservoir and release into the water. At 2.5ppm on the water column, there is likely a ton in the rock and sand.

 

[SeaDweller]

I'm not tracking nitrates yet. I'm upgrading soon and I'll be starting with 80%+ new water so I didn't think current nitrates were very important.

lets all take a guess. I'm gonna say 75 ppm NO3.

 

[jda]

...or < 1 if there is a sandbed and some real live rock.

 

[bpro32]

lets all take a guess. I'm gonna say 75 ppm NO3.

You made a game out of it, now I want to know! I'll have to find my nitrate test kit..

 

[SeaDweller]

You made a game out of it, now I want to know! I'll have to find my nitrate test kit..

you taking the high or low?

 

[bpro32]

Do not lower it too quickly or you might make your corals and inverts mad. Lowering P is not an issue, but doing it too fast can be.

Read up on phosphate binding to aragonite and how the aragonite can act like a reservoir and release into the water. At 2.5ppm on the water column, there is likely a ton in the rock and sand.

I used half of the recommended amount of GFO knowing that I should go slowly so I hope this is slow enough. The corals and fish all still appear happy but I'll keep my eye on it.

I read up on phosphate binding to aragonite, thanks for the recommendation! Sounds like this will be an uphill battle but if I can consistently keep phosphate low in the water it will leach out of the rocks and then GFO, chaeto, or my corals will remove it and eventually I'll be able to remove the GFO. I'm open to feedback so please let me know if I misunderstood what I read.

 

[bpro32]

you taking the high or low?

I'm taking under. I’ve done a lot of water changes recently and started feeding less.

 

[jda]

It takes a day or two for the aragonite to release back to "equilibrium." What you do not want is to use a bunch of GFO, lower the water level really low and then have it spike back up when the rock releases. Using a small amount and changing it often is good so that the GFO soaks it up at about the same pace that the aragonite releases.

 

[bpro32]

It takes a day or two for the aragonite to release back to "equilibrium." What you do not want is to use a bunch of GFO, lower the water level really low and then have it spike back up when the rock releases. Using a small amount and changing it often is good so that the GFO soaks it up at about the same pace that the aragonite releases.

This helps, thank you. I was wondering how long it would take to get back to equilibrium after it drops. So I can go slow with gfo and change it out every ~2 weeks. It somehow seems less daunting now.

 

[bpro32]

you taking the high or low?

Well... Pretty sure this is above 75.