[Left C]

Phosphate Testing Strips: Pool & Spa Water Testing - © LaMotte Company

What do you think?

They go from 0 to 2500 ppb which is 0 to 2.5 ppm.

The EI target range for PO4 is ~ 1.0 to 2.0 ppm

 

[spypet]

I would not get a phosphate test kit of any kind that did not have a clearly discernible range between 0ppm and 10ppm.
my tap water is already 2ppm, so a test between 0ppm and 2.5ppm is simply too narrow for any practical fish tank use.

 

[Left C]

I would not get a phosphate test kit of any kind that did not have a clearly discernible range between 0ppm and 10ppm.
my tap water is already 2ppm, so a test between 0ppm and 2.5ppm is simply too narrow for any practical fish tank use.

I've been thinking about this. I wonder what the kit shows/does when it exceeds 2.5 ppm. Is simply knowing that you are out of the 1 to 2 ppm range because you exceed 2.5 ppm good enough?

It only takes 15 seconds. You just throw it away when you're done. No test tube to clean up.

 

[spypet]

Is simply knowing that you are out of the 1 to 2 ppm range because you exceed 2.5 ppm good enough?

that may depend on your tap water and tank water quality tendencies. you see I have always suffered from a high phosphate problem, and I rarely get it down to 2ppm. I actually find 0-10 range useful while using my liquid test tube kit. if my phosphates are 2-5ppm I'm happy, if they are 5-10ppm then my tank may need attention soon, and beyond 10ppm reading may require immediate intervention. If they get above 10ppm, I may need to use a phosphate sponge media, as normal tank maintenance just ain't gonna cut it. keep in mind such phosphate spikes don't happen now that I'm more experienced, but back when my tank was cycling, algae infested, and basically running amok, having a wider range test was a godsend. don't be so afraid of liquid test tube test, since once your tank water stabilizes, you'll learn to "feel" how your water quality is from observing your fish, plants, and water. by then most of your test kits will go unused, at least until your tank has an unexplained crisis, or you establish yet another new tank.

to summarize, just knowing you are above 2.5ppm is not enough, since you won't know by how much and how immediately you will need to rectify your above range phosphate condition.

 

[Left C]

I found 9 different Phosphate test kit and looked up their testing range.

D-D/Merck ----- 0.00 -- 0.14 ppm
Lamotte ------- 0.00 -- 2.00 ppm
Salifert -------- 0.01 -- 2.00 ppm
Lamotte Strips - 0.00 -- 2.50 ppm
Seachem ------ 0.00 -- 3.00 ppm
Red Sea ------- 0.00 -- 3.00 ppm
Tunze --------- 0.25 -- 3.00 ppm
Hagen --------- 0.00 -- 5.00 ppm
Aquarium Pharm 0.00 -- 10.00 ppm


This is interesting:
- 6 of the 9 test kits measured from 0.00 to 3.00 ppm
- 1 was supersensitive 0.00 to 0.14 ppm
- 1 had a moderate range 0.00 to 5.00 ppm
- 1 had a wide range 0.00 to 10.00 ppm