Should I get the Phosphurous Checker?

[theokie]

Should I be getting the Hanna Phosphorus Checker? Now that I'm using LaCl more regularly, on a doser, my Phosphate checker consistently reads 0ppm. Is it worth it to get the Phosphorus Checker that will read down to ppb? Or should I just alter my dose so that I can get a detectable reading on my current checker and just adjust my maintenance dose around so that it reads 1ppm just so I know that I'm not over doing it?

This is for my SPS system, I've recently started to move all of my LPS out of it and about 80% have been moved over to the new LPS system. As I'm attempting to see if I will have better success by no longer trying to balance a mixed reef.

[asylumdown]

My 2 cents is that the phosphorous checked isn't worth the plastic it's made from. Unless you're using analytical lab methods (which include regularly washing your cuvettes in hydrochloric acid), its results are no more reliable than looking out your window and trying to guess the days temperature.

You're way better off looking at cues your tank is giving you, such as the rate film algae grows to get a sense of what's going on with phosphate in your system

[Jordon]

I really like mine. I rather not wait until A;age takes hold if i'm doing regular testing anyways. Knowing its on its way up via the checker before a visual cue is much better IMO.

I recommend it.

[tytown]

Just started measuring with Hanna ULR unit but have trouble getting the same reading twice. I've almost gone through a pack of reagent performing multiple measurements between my fresh, mix, and tank water. For example, tank readings were 57, 107, 35 (0.17, 0.32, 0.10 ppm), so I'm pretty much calling BS on this unit unless I'm doing something completely wrong... It's supposed to accurate to +-5% of its range so that's +-10 PPb or 0.03 ppm.
Does anyone get consistent readings close to the units rated accuracy???

[gregzz4]

There's been a number of posts on this topic lately, but they're hard to find as the spelling between phosphate and phosphorus is all mixed up

I like my Hanna HI 713 phosphate tester, but it takes some getting used to

[Aquattro]

I love mine, wouldn't use anything else. Then again, I tell the temp by looking out the window

[asylumdown]

Originally Posted by tytown

Just started measuring with Hanna ULR unit but have trouble getting the same reading twice. I've almost gone through a pack of reagent performing multiple measurements between my fresh, mix, and tank water. For example, tank readings were 57, 107, 35 (0.17, 0.32, 0.10 ppm), so I'm pretty much calling BS on this unit unless I'm doing something completely wrong... It's supposed to accurate to +-5% of its range so that's +-10 PPb or 0.03 ppm.
Does anyone get consistent readings close to the units rated accuracy???

nope. Never once. Thought it was me, then I looked in to it. Testing at that resolution outside of an analytical lab is about as accurate as guessing your level by throwing darts at chart.

To be consistent at that sensitivity, you'd need to be measuring the volume of your sample with a micro-pipette, using a fresh pipette every time you collected the sample. You'd also need to be getting the exact same amount of reagent out of the powder pillow every single time (which you never are). You'd also need to be washing your sample cuvette in hydrochloric acid every couple of tests, only ever rinsing the cuvette out in the purest of DI/distilled water, and doing dummy tests with DI/distilled water before each test, as tiny amounts of phosphate can bind to the glass.

You'd also need to be collecting your samples from the exact same spot, at the exact same time, after following the exact same routine. Even dipping your hand in to the water at the time you collect the sample could throw off the results enough to make the number meaningless.

It's why I prefer the regular PO4 kit. It's not as sensitive, and the numbers still need to be viewed as relative rather than absolutes, but at least it's more consistent from reading to reading and gives you a better sense of the actual trend in your tank. When one result is 0.10 and the next one 5 minutes later is 0.32, you have spent 15 minutes obtaining no useful information.

[Aquattro]

I use the regular unit, and for 4 years I consistently got 0ppm. Which was what I wanted to see. Good enough for me. I have an Elos kit, I can't tell if it's 0.01, 0.1, 42.8, etc. Might be my eyes

[Wheelman76]

I use the ULR phosphorous checker , works great and I can do two tests back to back and get very consistent results. Usually within 2 or 3 ppb. I think getting all of the powder out each time makes a big difference. I cut the edges of the packet off on two sides and then fold the packet into a V shape and pour. Seems to work well to get all of the powder out everytime.

[Wheelman76]

Originally Posted by tytown

Agree on the Elos PO4 kit, that thing is a total waste of money.

So Wheelman and Craig, what are some typical values your phosphorus checker reads? And what do you expect it to read when you test?

Running GFO I would hope to see 10 and below but going by their rated accuracy there's no way I guy can even rely on that.

Just trying to gauge peoples phosphates and their expected reading from their ULR phos checker....

Thanks for all the replys so far

I typically get a reading of 4ppb (0.01) to 10ppb (0.03) when I test. I usually change out my rowa phos every 4 weeks , but I recently decided to let it run for 6 weeks to see how high the po4 would climb. I tested and I got a reading of 20ppb (0.06) and then tested again right after with the same vile , rinsing in between with RO water and I got a reading of 21ppb (0.06) which seems pretty accurate to me.

I also agree that it's a good idea to only use the one vial for the test and just get the reagent in there quickly and have the packet open and ready to go. I also have the same side of the vial facing the front for the whole test ( steps C1 and C2) I just make sure the 10ml writing on the vial is facing the front. Is any of that necessary ? Who knows lol , but I get consistent results using this checker so that's how I continue to do it.