Should I get the Phosphurous Checker?

[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.

[Wheelman76]

I should have mentioned that I'm really carefull that I wipe all the fingerprints off the vial in between all the steps of the test. I'm not sure if that would lead to inconsistent readings that people are getting or not?

[lastlight]

yes i didn't mention that as i assumed everyone would be doing that already but for sure it makes a difference.

[mikellini]

Originally Posted by lastlight

if you like zero readings i highly recommend the phosphate checker =)

If you're doing it right, a zero reading is good enough. Even if it's actually 0.04 (which is possible with a zero reading), that's low enough. If I knew for a fact it was 0.04, I wouldn't try to chase numbers and lower it to 0.03. And as long as you have fish and are feeding enough, there will always be enough trace phosphorus in the water for hard corals.

My point is that if phosphates are a problem, it will read above 0, and if it doesn't and I'm having a problem, then phosphates aren't the problem.

[mikellini]

Wow there's gotta be a better way to say that haha

[Fishfriend]

I have a hanna phosphorous checker that I can sale you for $20. I am getting out of the hobbie.

[asylumdown]

Part of me wonders if it's the units themselves then, because people who can't seem to get consistent results never do, while the other camp never seems to have problems. I actually have training in analytical methods and have spent an unfortunate number of hours in a soil and water lab, and I still can't get mine to work properly.

I had a period where I thought my tank was melting down because every week I'd test 0.03-0.08 ppm higher than the week before - even with fresh GFO, and even while dosing lanthanum. Converted to ppm, I was reading in the 0.3 range.

Then i did a sequence of tests back to back in one sitting. The levels rose by 0.03 to 0.08 with each sequential test! the reading was predicted by the total number of tests I had run in that vial, not the level of phosphate in my tank.

I did the acid wash (which melted the max volume marker right off), then did a dummy test with distilled water and still got a reading of like 16 ppb or something.

I promptly drove to Wai's and bought a regular PO4 kit. That appears to have solved my phosphate problem, as my readings have been 0.00 ever since

[lastlight]

the Lastlight Checker Holder© is fully compatible with both Hanna models. comes complete with removable and washable funnel.

[asylumdown]

Brett, there are times when life gets busy and I get all distracted, and just for the tiniest moment I forget that you're my hero.

Then you remind me.

[tytown]

Ok, feeling better about it tonight. I went at it again but with the approach based on people's comments and some other research and was able to get a spread of readings within the units rated accuracy +-0.03 ppm (+-5% of range; range =200 PPb)
I perfectly prepped the reagent packet to ensure that it would all get in the vial before the test is even started
Grabbed water from the same location in the tank being careful not to get finger water in the sample.
I kept the orientation of the vial the same throughout all tests (10ml facing me)
And I used a fresh microfibre cloth and meticulously buffed the outside of the vial.
After all that it tells me I have 0.09 - 0.12 ppm PO4.
I would have liked to know which of the above had the largest influence on the results and I wonder what my readings would have been if the vial was flipped 180. Unfortunately I can't debunk the errors I went through becuase I only have 4 reagent packs left from my box of 25 bought just yesterday.
I'll use the current levels as a reference from here on out.
Thanks everyone.