kh - alkalinity ???

[fau8]

Okay I am confused on testing. I bought a kh test kit and it gives me results of in the 140 to 150 range. From reading other posts as long as it it under 200 there is nothing to worry about. Is this correct and why is kh showing up as 12.5 13.7 etc when people post there water parameters? Is there a conversion or is it a different test that gives results in this range.

 

[dennis210]

Check out thread by reefnut in archives alkalinity and Calcium Chart.

 

[fau8]

Thank you

 

[vince-1961]

you mean this.....???
Calcium & Alkalinity Chart

[hr]
Alkalinity__Alkalinity____Alkalinity_____Calcium
(meq/L)____(dKH)___(ppm CaCO3)__(ppm Ca++)
--0.0

[hr]
0.0

[hr]
0

[hr]
360
--0.5

[hr]
1.4

[hr]
25

[hr]
370
--1.0

[hr]
2.8

[hr]
50

[hr]
380
--1.5

[hr]
4.2

[hr]
75

[hr]
390
--2.0

[hr]
5.6

[hr]
100

[hr]
400
--2.5

[hr]
7.0

[hr]
125

[hr]
410
--3.0

[hr]
8.4

[hr]
150

[hr]
420
--3.5

[hr]
9.8

[hr]
175

[hr]
430
--4.0

[hr]
11.2

[hr]
200

[hr]
440
--4.5

[hr]
12.6

[hr]
225

[hr]
450
--5.0

[hr]
14.0

[hr]
250

[hr]
460
--5.5

[hr]
15.4

[hr]
275

[hr]
470
--6.0

[hr]
16.8

[hr]
300

[hr]
480
--6.5

[hr]
18.2

[hr]
325

[hr]
490
--7.0

[hr]
19.6

[hr]
350

[hr]
500
My Calcium tested out at 450 on one test and 520 on another, with alkalinity coming in at 1.7. How does this chart relate to those numbers?

 

[natclanwy]

I assume your kit is using meq/l for unit, and it means that your calcium is high, you need to get a repeatable test before you try to dose anything though. If your calcium is 450 just add enough buffer to get your alk to aprx 4.5meg/l and you will be set. If it is 550 stop dosing calcium and let it fall on its own then try to balance the alk and calcium.

 

[dennis210]

He said his test kit showed his alk to be in the 140 to 150 range. He got the impression that as long as he was under 200 he was fine. Then he saw people post there as 12.5 - 13.7. He asked about a conversion number or where he sould be. IE the chart for starters shows where yours numbers are.
So to get from alkalinity measured in ppm CaCO3 to a dKH reading you multiply by .056.
100 x .056 = 5.6
125 x .056 = 7.0
150 x .056 = 8.4
175 x .056 = 9.8
200 x .056 = 11.2
At any rate if you follow the chart and keep your alk in the 150 - 250 range
(8.4 - 14 dKH) you will be fine as long as your calcium is at a corresponding range of 420 -460.