I'll go with hanna ulr thx[emoji2]I guess this will depend on what you consider "cheap" and/or "reliable", usually those terms are inconsistent with each other. PO4 is one of those elements that needs to be kept at a relatively low number, that is beyond the error margins of most of our hobby grade test kits. So, for this test in particular I believe that the "cheapest" and most "reliable" kit would be the Hanna ULR Phosphorus test kit.
Thanks that's what I read about their differences:I believe that most people will suggest that you get the ULR.
http://www.aquacave.com/hanna-phosphorous-checker-ultra-low-range-hi736.html
It comes with 6 packets of reagent.
Here's 25 more for $8.99. http://www.aquacave.com/aquarium-mo...use-with-hanna-hi736-phosphorous-checker.html
Thanks.
Hi736 arrived. I tested using both vials.one to fill sw....one with sw and reagent. I did that since the unit shuts off if I don't do the mixing fast enough. Is this ok?
I inserted the first during c1 and inserted the second during c2.
Reading was 5ppb....is that high? What's ideal for a reef tank?
I might have made a mistake..I took sw from near gfo reactor output.maybe next time I will take sw from dt....to measure P.I don't bother messing with anything until I hit 10ppb. 5ppb is right where you want to be, good job!