how to get Phosphates lower than .06

[weiser5150]

So I am running phosguard in a media bag in a 20 gal AIO and cant seem to get my phosphates below .06.I am using a Hanna tester and I have read that they have a +/- of .04.My question is it inevitable that I am going to need to get a media reactor and run GFO or biopellets to keep the PO4 at a lower level?
I am very conscious when i feed fish and corals to make sure not to overfeed.

My other question is does anyone else think a +/- of .04 is a big swing either way for a digital tester?

[sticky polyps]

Don't quite understand the question about the +\- but yea there will be that variance. I think it may help to know the nitrate level too.

[AZRippster]

So I am running phosguard in a media bag in a 20 gal AIO and cant seem to get my phosphates below .06.I am using a Hanna tester and I have read that they have a +/- of .04.My question is it inevitable that I am going to need to get a media reactor and run GFO or biopellets to keep the PO4 at a lower level?
I am very conscious when i feed fish and corals to make sure not to overfeed.

My other question is does anyone else think a +/- of .04 is a big swing either way for a digital tester?

Not sure about Phosguard, but GFO performs its best when in a reactor and "gently" tumbling. Using it in a media bag is very inefficient and unlikely it will be very effective.

What test kit are you using? There will always be a +/- swing as hobby, even lab grade, tests have a margin of error. Hobby kits even more so.

[weiser5150]

Hannah digital

[stevenakaproek]

I've got my P04 @ 0.00-0.02

I have a reactor, but I don't run it. I just have carbon and ferric oxide in a mesh bag in the sump next to a power head. I have not seen any difference honestly. I also carbon dose using NOPOX which is what I contribute to the low phosphate

[bertoni]

Which Hanna phosphate meter are you using? They have three, plus some multi-parameter kits.

GFO does work best with a bit of tumbling, but a media bag should be okay as long as water is being forced through it.

[dkeller_nc]

First thing to consider is why you're trying to get the phosphate concentration under 0.06 ppm. If you've a specific algae problem, then it might make sense to do so. But many reef tanks are visibly healthy with steady phosphate numbers right around 50 ppb (0.05 ppm), so unless you've a specific issue you're trying to correct, I wouldn't be overly concerned about it.

As others on the thread noted, Granular Ferric Oxide does best when gently tumbling in a media reactor to prevent getting cemented up by precipitated calcium carbonate. However, tumbling PhosGuard would be unwise in my opinion. Phosguard is aluminum oxide, and is fragile. You really don't want powdered aluminum oxide dust getting distributed in your tank, so I'd keep it in its media bag if you choose to continue to use it.

[weiser5150]

Thanks for the info. I am not battling algae so I am just going to stick with the phosguard in the media bag.

[weiser5150]

Which Hanna phosphate meter are you using? They have three, plus some multi-parameter kits.

GFO does work best with a bit of tumbling, but a media bag should be okay as long as water is being forced through it.

HI 713 Low Range

[bertoni]

Okay, that meter is good to ±0.04 ppm, as you stated, so for all practical purposes, 0.06 ppm is low enough that the tank might be fine as is. I'd concentrate on watching the animals. More PhosGuard or more frequent media changes might reduce the level some, but it's not clear that it'd be beneficial.

[tmz]

I run PO4 at 0.02 to 0.04ppm as measured with the hanah 713 with occasional variations to 0.01 or 0.05/6.

[weiser5150]

Thanks for the info guys.

[bertoni]

You're welcome.