Salifert KH/Alk Test kit confusion?

[Reefaddict]

Is anyone familiar with the Salifert KH/Alk test kit?

I am very confused with the directions. I performed the test just fine, but to read the KH or alkalinity value you can use the table they provide or calculate the reading in step 5 times 16 for KH in dkh or times 5.71 for Alk in meq/L.

So if your not familiar with salifert your probably lost, but what I can't understand is, if you use the table they provide the readings are way way different from the calculated readings, if your multiplying by 16 and so forth.

So whats going on here is: the reading in step 5, as mentioned above, is the amount of KH reagent left in the syringe, after you've achieved the desired color,which is a orange red or pink color. So I have .18ml of KH reagent left in the syringe. If I use the table they provided then I take the .18ml and read right across the chart. This gives me 13.1 for a KH value in dKH. Reading straight across the chart this also gives me an alkalinity reading of 4.69 in meq/L...OK so thats using the table.

Now using the calculation method
If I were to multiply the .18ml by 16 to give me a KH in dKH, the value is 2.88. SO this make no sense! The chart/table says I have 13.1 for a KH in dKH and the calculations say 2.88 KH in dKH. To calculate for Alk in meq/L the directions say to multiply my .18ml by 5.71. So that gives me about 1.03 Alk in meq/L. The table says I have 4.69meq/L.

So obviously these readings are way different and Im way confused. How do you know what your reading are and what is the recommended levels?

Thanks for any help!!

 

[reefrunner69]

When I do the math, I get 13.12 DKH and 4.682 meq/L.

When using the math, you multiply by the amount of reagent used which is .82

 

[Reefaddict]

Oh MAN!! Thanks RR! LOL I was using the .18 to multiply with

So when using the table, you use the .18.....right?

So what is the optimum levels I should be at for a small reef?

Thanks again!

 

[reefrunner69]

So what is the optimum levels I should be at?

Well optimum is a relative term, LOL. You want your Alk to be ionicly balanced with your CA. I like to shoot for a CA of around 420 and a balanced alk (optimum for that CA reading) would be... around 8.3 DKH or around 3.0 meq/L.

For the ALK that you have 4.69 your CA should be around 450 ppm.

 

[reefrunner69]

So when using the table, you use the .18.....right?

Yes, personally I just use the table...it's easier, the only time I would bust out the calculator would be if I went over 1 cc of reagent (which I have done).

 

[Reefaddict]

WOW thanks so much ReefRunner, you've helped me out HUGE!

I do have one more question...How would I go about lowering my CA and ALK levels to optimum 420ca and 8.3dkh. I have ESV's B-Ionic, but that would only make the levels higher wouldn't it?

Thanks again

 

[reefrunner69]

I do have one more question...How would I go about lowering my CA and ALK levels to optimum 420ca and 8.3dkh.

Water change But there is nothing wrong with your levels where they are at. I said I shoot for 420 ppm CA with a balanced ALK, but if I tested and came up with 450 ppm CA and 4.69 meq/L ALK, I would be perfectly content. I would not like it to get much over 450 ppm though.