Is your phosphate stable?

[ChrisQ0904]

I have been able to keep almost all my parameters stable except my phosphate. I am using the hanna phosphorus ULR checker and I am getting swings from .01-.08, I know that they are not 100% accurate and I think I read they have an error range of +- .04 or something like that (could be very wrong about that). Either way I dont have an algae issue at all in my display which is most likely due to my ATS where there is healthy growth weekly. I guess I am just more curious if others are having big phosphate swings like that.

 

[Dan I]

If your tank is fairly new, then phosphate will jump on you. Might be rocks leaching or from many other things. My phosphate jumped all the way to 1.0 ppm. Lots of corals turned green and stopped growing. I have an ATS and skimmer and that didn't solve the issue. Had to pull out the the trusty GFO reactor and with 4 tablespoons of GFO it is holding steady at .26 ppm. Also, make sure your testing is done correctly, a lot of people have user error with the Hanna ULR tester.

 

[Larry L]

I am getting swings from .01-.08, I know that they are not 100% accurate and I think I read they have an error range of +- .04 or something like that

The advertised accuracy of the 736 ULR checker is ±5 ppb ±5% of reading, so e.g. a reading of 10 could be anywhere from 0.014 to 0.048 ppm phosphate.

I wrote a calculator that lets you enter your reading, and it tells you the range of min/max possible actual value taking that accuracy into account: http://larryl.emailplus.org/fish/test-kit-calculators.html

If your tank is fairly new, then phosphate will jump on you. Might be rocks leaching or from many other things.

Right, this can happen in older tanks too. If you have a lot of built-up phosphates in your rock or sandbed, you can knock down the phosphates in the water using e.g. lanthanum chloride or GFO, but then phosphates leach out of the rock or sandbed to take their place. Eventually if you keep at it, you'll reach an equilibrium and things will get more stable.

 

[ChrisQ0904]

My tank is technically new being setup only a few months, but the rock and starting water was from a 180g that I broke down but that was up for about a year before breaking down. @Larry L thank you for the link it is not bookmarked!