Sera carbonate hardness test kit

[jcolletteiii]

I've been using this test kit for some time, thinking it was very easy to use, inexpensive, and fairly accurate -> http://www.marinedepot.com/Sera_kH_Aquariu...-FITKCH-vi.html

 

Procedure.

It is very easy to use, being a low-end, single reagent kit. You simply draw up 5ml of water with the not included syringe, put it into the very nice covered glass test vial, and add drops of reagent. The test solution first turns a blue color, first darkening, then becoming green, and finally turning bright yellow when the end point is reached. The alkalinity (in dkH) is given by the number of drops used, and can generally be broken down to half numbers as well by the color of the solution prior to adding the last drop (if it is a yellow green as opposed to a darker green, you can surmise only 1/2 drop would finish the titration).

 

Accuracy.

I used to use quick strips to test pH, and still use them to test NH3, No2 and NO3, as they are very quick and fairly accurate. When I bgan using the Sera test kit, I checked its accuracy with the kH pad on the 5-way strip test that I was using at the time. According to the strips, the Sera kit was fairly close, so I thought it an upgrade from the test strips, and was fairly happy with teh results. I began to dose Alk supplement because my Alk was on the low side, 6-7, and I wanted my SPS growth to increase. I developed my dosing schedule, and over teh past month, have really dialed it in so that it stays pretty well between 7.5 and 8.5, or so I thought.

With testing every day (sometimes twice a day after dosing), the Sera kit was depleted fairly quickly. I ran outof reagent this morning, and went looking for another Alk test kit. I have a Salifert Mg test kit, and am happy with the results, so I picked up a Salifert Alk test kit as well. I was STUNNED by the different readings that I got with the Salifert test. My reading this morning with the Sera kit was 7.5. Two hours later, with no dosing, the Salifert kit gave a reading of 9.5! Yikes!

 

Verdict.

I have read reviews online of the Sera kit that suggest it is a good, inexpensive, fairly accurate alternative to a more expensive testing solution, and it is very definitely quick and easy to use. However, my test results do not indicate that it is accurate at all, and consistent Alk is very important to maintaining sps corals. The solution of known alkalinity supplied in the Salifert kit confirms the accuracy of the Salifert Alk kit, thus also confirming the inaccuracy of the Sera kit (which may read as much as 2 dkH off what the actual carbonate hardness of the tank water is). I recommend passing this test kit up in preference for the Salifert kit.

[lakshwadeep]

Great review! You might want to put your final recommendation in the title or towards the beginning of the post. At first glance, I thought this was a positive review.

[jcolletteiii]

Good idea - done.

[disaster999]

9.5dkh isnt consider too high.. some people keep it as high as 10-11dkh. it gives you enough buffer space so when the level does drop, its still in the "normal zone".

 

consistency is the key here.