testing water. The basics

coffeealex

Apologies for this. Its probably covered somewhere. I have just tested my tap water which is rated as moderately hard by water supplier. I have used an API kit. Results were:

15 drops to get a colour change on GH

9 drops to get a colour change on KH

How do I convert this to something meaningful please so I can enter it into maybe robs calculator?

MWJB

1 drop = 1 degree German (d) or 17.8mg/L as CaCO3

So your alkalinity is about 3x as much as you need at 160ppm or mg/L

coffeealex

MWJB

so is my water hardness 17.8 × 15 = 267 mg/L as CaCO3 ?

alkalinity 17.8 ×9 = 160.2ppm or mg/L ?

Rob1

Just make sure you’re adding the drops with the dropper held perfectly upright and you stop adding at the first sign of colour change.

coffeealex

Rob1

Rob1 Just make sure you’re adding the drops with the dropper held perfectly upright and you stop adding at the first sign of colour change.

Just repeated the test using your method and different results now:

GH down to 13 drops

KH down to 8 drops

so 17.8×13 = 231.4 mgl (CaCO3)

alkalinity = 17.8 ×8 =142.4 mgl or ppm

Have I entered them correctly?

Rob1

Yes, but you need to make sure you put the boiler temp in the temp cell. The service boiler will be easy enough to find but you need to know the brew boiler offset to figure out temps in the brew boiler, assuming it uses a pid.

coffeealex

Rob1 Ok thanks, so with service boiler I just look at the temp on the PID? and the brew boiler offset is 10 degrees c on mine, so do I just add 10 to the PID reading of the brew boiler?

Also I take it I enter temp in box 12, but which temperature do I enter there?

MediumRoastSteam

Enter the temperatures you see in the display for the steam boiler. If you want to know what the results are for your brew boiler, enter the temperature as shown in the display plus 10 (as that’s your offset).

coffeealex

MediumRoastSteam Thank you, I thought it was that but wanted to check. I am assuming box 12 on Robs calculator is used to input either/ or the service boiler/ brew boiler temps

Rob1

It’s either, not both. But not much point bothering as the results will just tell you you’ll get scale either way.

coffeealex

Rob1

Rob1 But not much point bothering as the results will just tell you you’ll get scale either way.

That is true. I was doing more as a learning curve. I was then going to measure my filtered water and other water to see how the figures changed and the impact that meant.