Chaeto not reducing phosphates

[JWhitener]

I have a 45 gallon AIO that has been sitting at 0.1 phosphates for 2 weeks. I only feed frozen food daily and does ocean magic phytoplankton every two days. I have some Chaeto in my refugium on the back of my tank that is about the size of a softball. I would think the Chaeto would have reduced my phosphates by now but it is constantly at 0.1. I know 0.1 isn't that high but I would rather be under a little bit. Any ideas on reducing?

 

[T-J]

Rinse your frozen food before feeding. I'm guessing your Chaeto is helping keep your PO4 at .1, meaning it would be higher if you didn't have the Chaeto.

 

[Deep]

I have a 45 gallon AIO that has been sitting at 0.1 phosphates for 2 weeks. I only feed frozen food daily and does ocean magic phytoplankton every two days. I have some Chaeto in my refugium on the back of my tank that is about the size of a softball. I would think the Chaeto would have reduced my phosphates by now but it is constantly at 0.1. I know 0.1 isn't that high but I would rather be under a little bit. Any ideas on reducing?

Is the chaeto growing and are you periodically removing some of it? Are your nitrates reducing ? If your chaeto is working as it should you will see a big drop in nitrates accompanied by a relatively small drop in phosphates.
If your primary goal is Phosphate reduction, I dont think Chaeto will help - try GFO, LC

 

[JWhitener]

Nitrates are lower at 5 ppm. The Chaeto is growing and I harvest it every couple of weeks.

 

[Dkeller_nc]

There's several possibilities. You didn't state whether by "0.1 phosphate" you mean 0.1 ppm phosphate. If that's the case, and you're actually stating your phosphate level (instead of phosphorus level - multiply by 3 if your test gives you phosphorus concentration instead of phosphate), then you'd have about 100 ppb phosphate. That level is within the desired range for a reef tank, and especially if you have sensitive stony coral species like acropora, I wouldn't recommend reducing it. Especially if it's done quickly.

From the standpoint of the explanation of why the phosphate level isn't changing, it's possible that your test is near its lower limit of sensitivity. That would be the case for the almost all tests on the market except for the Hanna checker tests. If you are using a Hanna Checker ultra-low-range phosphate meter (which should yield accurate results in the 100ppb range), it may simply be that the rate of phosphate addition that you're introducing with food is the same (roughly) as you're taking out with your skimmer and chaeto.

 

[blasterman]

I disagree. Never seen chaeto do much with phosphate.

 

[IslandLifeReef]

There's several possibilities. You didn't state whether by "0.1 phosphate" you mean 0.1 ppm phosphate. If that's the case, and you're actually stating your phosphate level (instead of phosphorus level - multiply by 3 if your test gives you phosphorus concentration instead of phosphate), then you'd have about 100 ppb phosphate. That level is within the desired range for a reef tank, and especially if you have sensitive stony coral species like acropora, I wouldn't recommend reducing it. Especially if it's done quickly.

From the standpoint of the explanation of why the phosphate level isn't changing, it's possible that your test is near its lower limit of sensitivity. That would be the case for the almost all tests on the market except for the Hanna checker tests. If you are using a Hanna Checker ultra-low-range phosphate meter (which should yield accurate results in the 100ppb range), it may simply be that the rate of phosphate addition that you're introducing with food is the same (roughly) as you're taking out with your skimmer and chaeto.

100 ppb PO4 is the same thing as 0.1 ppm PO4. So I really don’t know what you are trying to say. Are you suggesting that the OP converted their phosphorus reading from ppb to ppm? If so, a 100 ppb phosphorus reading would be very high for a reef tank.

 

[Dkeller_nc]

100 ppb PO4 is the same thing as 0.1 ppm PO4. So I really don’t know what you are trying to say. Are you suggesting that the OP converted their phosphorus reading from ppb to ppm? If so, a 100 ppb phosphorus reading would be very high for a reef tank.

The OP stated that their phosphates were "0.1" - no units. There's a pretty good bet that he actually meant "0.1 ppm phosphate", but I asked just to make sure. And with a Hanna Checker (at least the 713 model), it would report the phosphate concentration as two digits (as phosphate), so I was just asking the OP to confirm what test he was using. If it's the appropriate Hanna Checker, no problem. But there are many non-colorimeter liquid reagent phosphate tests that would be useful for a FOWLR, but not so much for a reef.

 

[NeonRabbit221B]

You may be deficient in minor elements like Iron.

Recently I have had a phosphate issue that revolved around my DI resin being depleted and having a faulty TDS meter. Essentially I was dosing phosphate via my ATO and it appeared my Chaeto wasnt doing anything. If you chaeto is growing then you likely have an input issue (rocks leeching, Poor RODI, or food as mentioned above).