Fresh Salt Mix Reading PO4

[Angel_V_the_reefer]

Hello R2R.

my freshly mixed HW Marine Reefer Salt is producing .08 PO4 on a Hanna checker. I am curious as to whether this has been my problem with phosphates.

I have a 10G holding tank with a pair of clowns and a few hammer corals that will be regimes into a nuvo 20 in the near future.

i perform 50% water changes to keep nutrients low but I have noticed my phosphates have been shooting up although I don’t have heavy bio lid or heavy feeding (although I feed pellets)

what could be the source of PO4 ? RODI ? ( 0 TDS, 6 stage BRS unit with dual carbon block and DI Resin)

 

[Randy Holmes-Farley Verified Community Expert]

That’s unimportantly low. Ignore it.

Aquarium Chemistry: Phosphate And Math: Yes You Need To Understand Both

Foods are by far the most important source of phosphate in most aquariums. In considering whether sources of phosphate other than foods are important, one must carefully look to the actual amounts involved to determine whether other sources are even worth trying to minimize.

reefs.com

Comparison of Food Sources of Phosphate to Other Sources​

What about other sources of phosphate, like the “crappy” RO/DI water containing 0.05 ppm phosphate? A similar analysis will show it equally unimportant relative to foods.

Let’s assume that the aquarist in question adds 1% of the total tank volume each day with RO/DI to replace evaporation. Simple math shows that the 0.05 ppm in the RO/DI becomes 0.0005 ppm added each day to the phosphate concentration in the aquarium. That dilution step is critical, taking a scary number like 0.05 ppm down to an almost meaningless 0.0005 ppm daily addition. Since that 0.0005 ppm is 40-600 times lower than the amount added each day in foods (Table 4), it does not seem worthy of the angst many aquarists put on such measurements. That said, tap water could have as much as 5 ppm phosphate, and that value could then become a dominating source of phosphate and would be quite problematic. Purifying tap water is important for this and many other reasons.

 

[Angel_V_the_reefer]

That’s unimportantly low. Ignore it.

Aquarium Chemistry: Phosphate And Math: Yes You Need To Understand Both

Foods are by far the most important source of phosphate in most aquariums. In considering whether sources of phosphate other than foods are important, one must carefully look to the actual amounts involved to determine whether other sources are even worth trying to minimize.

reefs.com

Comparison of Food Sources of Phosphate to Other Sources​

What about other sources of phosphate, like the “crappy” RO/DI water containing 0.05 ppm phosphate? A similar analysis will show it equally unimportant relative to foods.

Let’s assume that the aquarist in question adds 1% of the total tank volume each day with RO/DI to replace evaporation. Simple math shows that the 0.05 ppm in the RO/DI becomes 0.0005 ppm added each day to the phosphate concentration in the aquarium. That dilution step is critical, taking a scary number like 0.05 ppm down to an almost meaningless 0.0005 ppm daily addition. Since that 0.0005 ppm is 40-600 times lower than the amount added each day in foods (Table 4), it does not seem worthy of the angst many aquarists put on such measurements. That said, tap water could have as much as 5 ppm phosphate, and that value could then become a dominating source of phosphate and would be quite problematic. Purifying tap water is important for this and many other reasons.

Makes sense ! I wasn’t sure whether to blame the salt or water for the problem , although 50% water changes would add .04 ppm phosphates , at least I believe.

I agree though that the foods we feed are very nutrient dense and should be of more worry. I have had a few days where a few pellets sank to the bottom so that could even be my source of phosphates.

I really appreciate the feed back Randy, blessed my worries away