Phosphates positive, how to control

[mikee002]

my phosphates have been consistently testing at .25 (api test kit), nitrate nitrite and ammonia all zero. For nutrient export I’m doing weekly 10% water changes and chaeto in the Refugium. I have minor brownish algae in the sand bed, nothing in the rocks. I have a lot of algae that grows in the sump, including on the chateo (which I’m not a fan of). My grow light spills everywhere and isn’t confined just to the refugium compartment. I don’t think I overfeed and I’m not overstocked. 4 fish in a 35g cube. I feed half cube of 50/50 a day. No corals yet, just a rock anemone. Various cleanup crew.

Will adding a skimmer help with phosphates? I really don’t want 0 nutrients as I know some corals and anemones prefer some nutrients. What other options do I have for phosphate control?

 

[Crazeh]

Do you use RODI water? First thing to check is that you're not putting phosphates in with your water changes!

If phosphates are just coming from your natural bioload then one good way to control is with GFO (granular ferric oxide). It can be run in a media reactor, or in a media bag with good flow.

 

[mikee002]

Do you use RODI water? First thing to check is that you're not putting phosphates in with your water changes!

If phosphates are just coming from your natural bioload then one good way to control is with GFO (granular ferric oxide). It can be run in a media reactor, or in a media bag with good flow.

Didn’t even think of checking my rodi... using a BRS 4 stage.

 

[EmdeReef]

I don’t think API kits are good for testing phosphates. I would get a better test kit or invest in a Hanna checker.

GFO, aluminum based phosphate removers, and lanthanum chloride are some of the methods to remove phosphates. For more info I recommend this article:

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

 

[biophilia]

It’s worth noting that the resolution of the API phosphate test kit is such that your actual PO4 level may not be anywhere near .25ppm. If you’re not experiencing any major issues in the display itself it may be worth checking a more accurate test kit first just to make sure.

 

[mikee002]

It’s worth noting that the resolution of the API phosphate test kit is such that your actual PO4 level may not be anywhere near .25ppm. If you’re not experiencing any major issues in the display itself it may be worth checking a more accurate test kit first just to make sure.

Okay, I’ll look into new tests. The LFS suggested this one so I tried it.

 

[Rick.45cal]

Even if your phosphates are really .25 ppm I personally would do nothing about it. That’s not a bad number, phosphates aren’t an evil thing. Not having phosphates is much worse than having a lot of them.