Testing comparison:
I was not happy with the wide variation I was getting between my API test kit and my Jungle Quick Dips and thought that it would be wise to get some independent testing. I loaded up a quart of tank water, grabbed my API kit, Quick Dip and Hydrometer and headed over to Imagine Ocean.
Jenn was there and she was intrigued by the idea of another testing comparison and was completely on board to work with me on this experiment.
On to the results...
(1) Specific Density
- my Hydrometer - 1.023
- Jenn's Refractometer - 1.023
So far so good. :tongue: We matched and I feel good that my Hydrometer is currently working perfectly. I'm still buying a Refractometer as it is too fun of a toy to pass up.
Please note that all of the following tests were performed by Jenn with me playing lab assistant. Where appropriate we had three sets of eyes doing an independent blind grade of the results.
(2) pH
- API - 8.1 (Bill) 7.9 (Jenn) 7.9 (Brian)
- Jungle Quick Dip - 8.3 (Bill) 8.2 (Jenn) 8.1 (Brian)
- SeaChem - 8.2 (Bill) 8.1 (Jenn) 8.1 (Brian)
(3) Ammonia
- API - 0.75 (Bill) 0.75 (Jenn) 0.50 (Brian)
- Jungle Quick Dip - n/a, the Quick Dip does not measure Ammonia
- SeaChem - 0.7 (Bill) 0.4 (Jenn) 0.4 (Brian)
(4) Nitrite
- API - 1.0 (Bill) 1.0 (Jenn) 1.0 (Brian)
- Jungle Quick Dip - 2.0 (Bill) 2.0 (Jenn) 1.5 (Brian)
- SeaChem - 4.0 (Bill) 2.5 (Jenn) 4.0 (Brian)
(5) Nitrate
- API - 15 (Bill) 15 (Jenn) 15 (Brian)
- Jungle Quick Dip - 20 (Bill) 15 (Jenn) 15 (Brian)
- SeaChem - 1.5 (Bill) 2.0 (Jenn) 2.0 (Brian) - After looking at these results I'm not sure if the Nitrate scale used was the same.
(6) Alkalinity
- API - n/a, API does not test Alkalinity in my set
- Jungle Quick Dip - n/a, we got a funky blue color on the test strip that had no assigned color to grade against. We tested the sample twice and got the same n/a color both times.
- SeaChem - 3 (Jenn) - This was a titration test so there was no blind evaluation.
(7) Magnesium
- Red Sea - 1200 (Jenn) - This was a titration test so no blind evaluation.
- SeaChem - 875 (Jenn) - This was a titration test so no blind evaluation.
There was such a big difference here that we pulled out the reference sample from SeaChem with a known value of 1080. We tested the Red Sea test against it and came up with a value of 1300. We tested the reference with the SeaChem test and came in right at 1080. To make matters worse for the Red Sea kit was that it was almost impossible to fill the syringe as the chemical bottle to draw from had a dropper top.
It took two of us and a lot of spilled reagent to get the syringe filled properly. Aggravating the problem was the issue of the syringe and the supplied needle not coupling correctly. The test was, for all practical purposes, unusable. When we finally got the syringe filled the test seemed to overstate the Magnesium by a material amount.
(8) Calcium
- Sera - 300 (Jenn) - This was a titration test so there was no blind evaluation.
- SeaChem - 300 (Jenn) - This was a titration test so there was no blind evaluation.
We also tested the Sera against the SeaChem reference liquid with a known value of 450 and it matched perfectly. I have a lot of confidence that both the SeaChem and Sera gave an accurate reading. The difference between the two is that you must remember the number of drops with Sera while you use a syringe for measurement with SeaChem.
So, what did I learn?
1. User judgement plays a factor as the three of us "graded" the results differently.
2. I like the little white tray that SeaChem uses so that you can do most of your tests at once without fiddling around with vials.
3. The Red Sea Magnesium test is not going to work for me. Maybe I got a defective vial and syringe but as it stands, it is unusable for solo testing. Even when we got it to work the results were very suspicious.
4. The Sera test was right on and very easy to use even though the spoon for adding the powder was a bit tricky. I like the measuring spoon better with SeaChem but that is a pretty minor point.
5. I'm not a big fan of the Quick Dip strips as they are harder to interpret and probably only good to give you a quick read of basic tank parameters.
6. The color cards with SeaChem are awesome. SeaChem uses a white card with a "window" that has a color strip threaded through it. You can very easily isolate the right color vs. the color cards that API uses. I do wish that the "units" for the hash marks between the numbers clearly marked.
7. Hydrometers can give you a funky reading if you aren't careful about air bubbles.
8. Light plays a factor, grade in a well lit place with natural light if possible.
9. Overall I have more confidence in SeaChem than API or Quick Dips. SeaChem seems to be more consistently on target.
A huge :thanks: goes out to Jenn and Imagine Ocean for helping me with this. You are wonderfully patient, especially since this was supposed to be your day off.