Red SeaFish Pharm ARE21411 Reagent KH/Alkalinity Pro Kit Refill for Aquarium, 75 Tests

Always use dedicated vials and syringes with these kits. Don't mix and match between the different tests. I generally consider red sea titration tests very accurate but it really doesn't matter. Just try to stay with the same tests because it's more important to maintain stability than to chase numbers.

Great way to refill a single reagent of your Red Sea kits, the refill solution actually had a better color change which made it easier to get accurate readings than the original bottle of solution that came in the kit. Would definitely recommend this to anyone looking to refill their Alk testing solution in a red sea kit. Note that it does come with a new plastic syringe with it but you will need to use the glass bottle and holder from your existing kit with this refill package.

Red sea replaced the original color agent or whatever with this one which is a much clearer change. Much better choice than some of the cheaper alk test and I continue to get the refills. I only wish the refills were 10 bucks.

Been using for year. Accurate and easy to read!

I tested my reef water three times with this kit and got a different result each time. My old kit worked right so I must have gotten a bottle from a bad batch.

It’s confusing whenever you get to the changes f color. It says red but the reagent shows different color. I use Hanna checker now

Not much more to say on this. It works well just like Red Sea products do. Been using them for awhile.

Works as designed.