Got My County Water Test - ARGH!!!!

[Roan Art]

Can someone recommend an ACCURATE nitrate test? I've been testing my nitrates out of the tap as from 5-7ppm. BUT according to the water report:

Nitrate Average for 2005: 1.0 mg/l

WHAT?

No WONDER I have algae problems! Maybe I should just stop with the darn testing and go with EI :)

And PO4? It says "Phosphates as Phosporous" average .02
My kit reads 2.5ppm
Now, is this the "good" plant phosphate or no?

The interesting thing is the Ca level. My kit reads 40ppm atm and for last year the numbers were 65 in April and 56 in May, so it's pretty close.

Roan

[wesleydnunder]

Glad you brought this up, Roan. I'm using the AP freshwater master test kit and I know my nitrate tests are inaccurate. I kept increasing my nitrate dosing only to find that the most this kit will show is 5ppm. I tried a new kit and had the same results. I put 1/4 tsp of KNO3 in 1 cup of water which should have showed up as red on the chart. I got an amber color. I've ordered a red sea nitrate test to see if it is better.

Mark

[carpguy]

Maybe I should just stop with the darn testing and go with EI :)
Maybe?

I just test because I like the test tubes.

And I like monitoring the whole thing. But EI works better than my test kits.

[EcoPit]

First off, you bolded it yourself: AVERAGE. And the 2005 average at that. Just because the 2005 average is 1 ppm doesn't mean that 5 or even 7 ppm four months into 2006 is impossible. There could have been days in 2005 where it was 10 ppm or more and the year still could have averaged out to 1 ppm.

Maybe I misread or misunderstood Tom's article (entirely possible), but even with EI you still need some idea of what the levels are in your water. If I want 10 ppm nitrate and 1 ppm phosphate in my tank I am not just going to add them, because what if my tap water has 2.5 ppm phosphate? With a 50% water change I would be raising the phosphate conc. in the tank 1.25 ppm, then adding another 1 ppm would make it way above what I wanted. I thought that with EI you basically just don't have to worry about levels exceeding certain concentrations, so long as you do the regular large water changes. You still want to make sure you are adding things at the correct amounts and ratios though.

[Roan Art]

First off, you bolded it yourself: AVERAGE. And the 2005 average at that. Just because the 2005 average is 1 ppm doesn't mean that 5 or even 7 ppm four months into 2006 is impossible. There could have been days in 2005 where it was 10 ppm or more and the year still could have averaged out to 1 ppm.
I have the numbers for 2005 and if any of them were even close to what I had been testing at, believe me, I would have said so :)

The HIGHEST number in 2005 was 1.5ppm in February.
Jan --
Feb 1.5
Mar 1.2
Apr 0.9
May 0.7
Jun 0.9
July --
Aug 0.7
Sept 0.7
Oct 1.0
Nov --
Dec 1.4
Average 1.0
Max 1.5
Min 0.7
# of Tests 9

My tap test *always* reads 5-10ppm NO3

Maybe I misread or misunderstood Tom's article (entirely possible), but even with EI you still need some idea of what the levels are in your water. If I want 10 ppm nitrate and 1 ppm phosphate in my tank I am not just going to add them, because what if my tap water has 2.5 ppm phosphate? With a 50% water change I would be raising the phosphate conc. in the tank 1.25 ppm, then adding another 1 ppm would make it way above what I wanted. I thought that with EI you basically just don't have to worry about levels exceeding certain concentrations, so long as you do the regular large water changes. You still want to make sure you are adding things at the correct amounts and ratios though.That is why I got a county water report, Ecopit :)

Now I know EXACTLY what goes in my tank out of the tap.

Roan

[Roan Art]

Maybe?

I just test because I like the test tubes. Me too :D

And I like monitoring the whole thing. But EI works better than my test kits.I agree!

Roan

[carpguy]

I thought that with EI you basically just don't have to worry about levels exceeding certain concentrations, so long as you do the regular large water changes. You still want to make sure you are adding things at the correct amounts and ratios though. Tom doesn't seem to place much stock in levels or ratios. Or in test kits.

Its nice to have an idea about where your levels are and dose accordingly but you can go over by a good bit without having a problem. The reset is so that things don't get absolutely squirrelly.

A good part of the point behind EI is that there is no way you could know about halves of parts per millions with hobbyist kits. They're OK for relative readings and should be calibrated to known quantities. I use my Nitrate test kit to tell me high, medium and low: I don't trust it well enough to think I can work out a reliable reading within 10 ppm. They just aren't all that accurate.

[RTR]

If you want the real test kits, you go Hach or LaMotte:

http://www.lamotte.com/

http://www.hach.com/

These are the standards for field testing and as such are many times as accurate, precise , and reproducible as hobby kits. They still are not lab grade analyses.

The analyses offered by utilities are at the source, post-processing but befire being sent into the distribution network. Whether or not you analysis mathches that at the pkant depends on the distance of your sample port from the processing plant and the status of the lined between the two.

For any hope of accuracy, you would have to go to the the plant and be given a sample from their test ports to run in parallel with you port sample, plus a known zero sample and a positive sample in the range in which you are interested. NO yest or analysis has any validity without zero and calibrated positive samples (all perferably run blind to the operator).

[Roan Art]

If you want the real test kits, you go Hach or LaMotte:

http://www.lamotte.com/

http://www.hach.com/44-55$ for a nitrate kit with 50 tests? *swoon*

These are the standards for field testing and as such are many times as accurate, precise , and reproducible as hobby kits. They still are not lab grade analyses.Yah, there is that :)

The analyses offered by utilities are at the source, post-processing but befire being sent into the distribution network. Whether or not you analysis mathches that at the pkant depends on the distance of your sample port from the processing plant and the status of the lined between the two.

For any hope of accuracy, you would have to go to the the plant and be given a sample from their test ports to run in parallel with you port sample, plus a known zero sample and a positive sample in the range in which you are interested. NO yest or analysis has any validity without zero and calibrated positive samples (all perferably run blind to the operator).Okay, so the test is not exact ;), but it certainly is a lot better than the test results I've been getting with AP nitrate tests. All the other tests I've run have been very close to their report. The pH was dead on, as was the alkalinity. Ca was very close. There are even numbers on TDS.

How do I convert ug/L to ppm? For iron?

Roan

[RTR]

For our purposes ppm = mg/L (not exactly, but too close to identity to be considered in our tanks) and there are 1,000 micrograms per milligram, so 1 microgram = 0.001 milligram.

The field test kits are expensive because the readers of the color changes are high quality. The refills are not very expensive, most under $20. The chemistries are similar or identical to hobby kits, but the reagents are high grade and carefully controlled. The readers are fantastic. Standards are available for many of the tests, and the expirations dates actually mean something.

It is a cost/value issue, but I don't suggest that everybody spend more on their test kits than on their setups. Most folks do not have any requirement for that accuracy. They need most to know the direction of change in levels of tested materials and a rough order of magnitude of that change. Everything else is most easily and often best handled by water changes and/or supplements or both. There I do agree with Tom Barr very strongly, but I also generalize it more broadly to FO tanks and not just planted. If everyone were indoctrinated with the concept of large-scale frequent partials, a non-trivial percentages of the problems we see on these forums would be history.

If we could with same magic wand to make disappear the idea that tanks were color and form decorator boxes and that maximizing the number of inhabitants was desirable, well, then we would have only a fraction of the current post levels, especially if we could somehow incorporate the need of QT in the general conciousness. I have never understood the concept that the tank version of rush hour could be an aesthetic or pleasurable experience. I am apparently from a different planet from most of my fellow hobbyists.

Off soap box, return to prior programming... ;)

[joephys]

For what its worth, there was a town in washington that got into some trouble for lying about its water quality a few months ago.

[EcoPit]

I just don't think water company figures would be that useful. How often do they test? Some water companies get water from a variety of sources, so the parameters can change quickly and drstically (although hopefully not with great frequency). Unless they are testing regularly (which I would hope they are) and making all of those results available to their customers then I don't see how it would be useful. Interesting yes, but not useful. Plus, anything can happen between where they test and your tap, so those numbers could be different by the time the water gets to your watwer change bucket.

I am not telling anyone to do anything differently. For me though, the water company test results are interesting to look through, but I am not going to base my dosing off of them.