Red Sea KH test kit

Zwogle · Jan 17, 2017

I have been using API's kit which was pretty easy to read (pretty steady at 8.5-9), but wanted to try out Red Sea. I'm wondering if anyone has any guidance on using this test, i'm trying to figure out when the correct color change happens. Another question is, do the color ranges in the attached image look like what current user see (The colors look VERY different from Red Sea's instructional video )?

Joeganja · Jan 17, 2017

I went from
Red Sea to salifert for the alkalinity test and found it to be much easier to read and reliable then Red Sea. It seems as if you don't get the same hue of coloration that they specify in the instructions so you have to kind of guess.

a49panhead · Jan 17, 2017

Red Sea has a recall an the kh test kit. If u contact them through their website they will give you a new test kit. It should turn red

Randy Holmes-Farley · Jan 17, 2017

If you have a pH meter, you can judge the color of the endpoint yourself. The endpoint is at pH about 4.2 for normal seawater, but high precision is not required.

fragit · Jan 17, 2017

a49panhead said:
Red Sea has a recall an the kh test kit. If u contact them through their website they will give you a new test kit. It should turn red

Wow thanks for letting us know RedSea! I've been wondering about the color change for quite some time. I ordered a refill for my alk then switched to the Hanna dkh meter. I'm gonna contact RedSea and get a new kit.

Joeganja · Jan 17, 2017

a49panhead said:
Red Sea has a recall an the kh test kit. If u contact them through their website they will give you a new test kit. It should turn red

There is your proof.

Scurvy · Jan 17, 2017

My KH test colors look about the same. I stop pretty much around the same endpoint as you or at least that last image. They don't really get to the same color levels IME as the cards show but are pretty acurrate when compared to the Hanna checker I got due to the same uncertainties... They're usually +/- .2 dkh.

a49panhead · Jan 17, 2017

Joeganja said:
There is your proof.

They replaced mine not 2 months ago cuz it went gray then orange

fragit · Jan 17, 2017

I emailed them this morning right after I read this thread. They responded already, saying they are sending me a new reagent bottle.

jsker · Jan 17, 2017

Randy Holmes-Farley said:
If you have a pH meter, you can judge the color of the endpoint yourself. The endpoint is at pH about 4.2 for normal seawater, but high precision is not required.

Good to know

AllSignsPointToFish · Jan 17, 2017

I usually stop at the last image on the right. I don't really care about the absolute value of the dKH as long as it is in range and is repeatable. Big shifts are what I'm trying to prevent.

Joeganja · Jan 17, 2017

fragit said:
I emailed them this morning right after I read this thread. They responded already, saying they are sending me a new reagent bottle.

Same.

Zwogle · Jan 17, 2017

This is Red Seas response:
"The usual end color is going to be an orangish/peach color. if looking at the photo that you sent over the reading would be taken at the 4 photo. The brighter peach color is just the same just over saturated with the reagent. If you would like we can send out a replacement reagent."

Hopefully with the new reagent the color change will be more obvious, between 3,4,5 the color variance is not too distinct.

Zwogle · Jan 18, 2017

Zwogle said:
This is Red Seas response:
"The usual end color is going to be an orangish/peach color. if looking at the photo that you sent over the reading would be taken at the 4 photo. The brighter peach color is just the same just over saturated with the reagent. If you would like we can send out a replacement reagent."

Hopefully with the new reagent the color change will be more obvious, between 3,4,5 the color variance is not too distinct.

Well It looks like I won't be getting a replacement, since I'm in AK shipping would be $30...