Lab results compared with hobby test kits

[Ron Reefman]

I would be concerned about evaporation during transit which would lead to higher test results. Are they bringing this test water back to normal salinity ratios before testing? i'm not really familiar with the company, but if their sole purpose is to test "aquarium" water why are their number so off?

How do you evaporate water from a sealed container over a couple of days?

 

[KSzegi]

Agreed, don't think evaporation was an issue. Perhaps some other issues of stability during the transit though, I don't know how it would have affected the samples but I would think it is a possibility. I did speak with a rep about their methods and results - calcium in particular since that seemed to be low on all the results. I was told that it was done by electrode and it was lower than what we typically see because it was measuring only free calcium, not total free and bound.....not to be concerned with levels that were above 100 and that they were in the process of re-doing the 'normal range' values on that test. Quite honestly, although very friendly, the conversation did not inspire a whole lot of confidence ......

I have received the test bottles from another lab (ENC labs) - and will be sending samples from the same tank to them for analysis most likely on Monday. Some differences I see already (besides price!) is that their sample bottles are said to have been acid cleaned for trace anaylsis, the volume of water to be sent is much greater, they highly recommend overnight shipping of samples back to them and want to know date and time that samples were taken and when they get shipped back to them. They will also no longer test for nitrate or iodide because they are too unstable to provide meaningful information.

Will post results when received!

 

[VIPReef]

How do you evaporate water from a sealed container over a couple of days?

Water does evaporate in a sealed container, however the droplets will be retained inside the container along the walls and lid of container assuming container is airtight. If not airtight, then that's a whole other issue. Like I said, I'm not familiar with the company or the methods they use for sample testing just trying to understand the cause of this. Do you have any ideas?

 

[KSzegi]

So, I sent samples to another lab recommended as a far more precise and accurate analytical lab. Although I have not received all results back yet, I did get a few and thought I would share .....

I think the most interesting is the results for phosphates and total phosphorous. At those levels I think I am going to try taking the gfo offline for a little bit and monitor the corals reactions. Have been getting zero readings for some time but even with the hanna checker, I really didn't think that the levels would be this low - and I am curious to see what allowing a little phosphate back into the water will do.

Total- PHOS .005ppm/5ppb (nsw 60-70ppb) This result was after vigorous digestion.
phosphate is tested as - Not Detectable, <.003, "no phosphate was detected in your sample".

Cadmium .05 ppb (nsw .01)
Copper 1.5ppb (nsw .05-2)
lead .3ppb (nsw .03)

 

[jdpiii3]

What lab did you send the new sample to?

 

[KSzegi]

ENC Labs