Alge scubber.

[nicholasb]

Just curious to know. Have been watching C.J (of 'C.J's aquariums' on you tube) starting his new 120g tank. His phosphate levels were 0.5ppm (Hannah checker phosphorus), after the cycle using dry dead rock.. This was due to the rock having some dead matter on it, which helped the cycle, and created the high phosphate. He now has 5 fish in the tank, including 3 tangs. His phosphate levels have dropped to 0.009 ppm. This partly through large water changes, and partly through the use of a Santa Monica algae scrubber. No other phosphate removal method is used, apart from a skimmer on the tank. If a scrubber could really suck out phosphates to 0.009, I would be temped to give a scrubber a go, instead of using 'rowa phos' (G.F.O). C.J's scrubber was full of fast growing hair algae. I was under the impression that phosphate levels below 0.03ppm, caused very limited growth in hair algae. May be the test result is faulty. The maths he used to convert phosphorus to phosphate looks right. The scrubber just looks to good to be true.
What phosphate levels can you get using a scrubber?.
I am not new to hobby, just new when it comes to scrubbers.

 

[tmz]

IME think many of the commercial scrubbers are too small and poorly designed to achieve less than .01 ppm PO4.
At some point the rock stops leaching ; I'd bet on the water changes as a primary reducer in the case noted. It is also my experience that most macro algae struggles much below .05ppm ;there are , however,some oligotrophic alges that can survive lower ranges of nutrients. I've tried several diy versions over the years but don't use one currently,fwiw.

As for dry rock ,I prefer to cure it and monitor PO4 levels along the way, recuding them with lanathanum chloride treatments in the curing bin if needed during the curing.