Seven Trent Water

[PureGuiness]

yes. a 5ml one and a 1ml one.

[kevthebootboy]

ah yes,
ive got 20 ml syringe i use for measuring my iodophor,

oh and while im at it, do you test your water befor or after removing the chlorine? or does it not matter?

[kevthebootboy]

Nice one cheers Chris.

[Dr.Evil]

The nutrafin kit was specifically the kit I was refering to, it wasn't even in the ball park. I couldn't even fudge it to give the correct figure.

Interesting. The total hardness value I got was within 2% of the value published by my water company. The alkalinity value gave a bang-on mash pH when using it to calculate how much CRS i need to add. Perhaps you got a duff kit. Could be more evidence to support the safilert as the kit of choice (ie. perhaps the Nutrafin kits are inconsistent).

[kevthebootboy]

I've got my testing kit,CRS and sodium metabisulphite, so hopefully I'll get chance over the weekend to sort the water test out,I want to be brewing next weekend and I look forward to not having to lug 45 litres of bottled water around! Thanks again Chris,I'll let you know how I get on

[Dr.Evil]

If I recall correctly there were 2 problems with the Nutrafin kit. Firstly the 5ml line on the test tube wasn't actually 5 mls and secondly the dropper was poorly designed/poor quality and the drop size was likely to be inconsistent.

Looks like they have improved the kit. The test-tube supplied was a reasonable quality glass one. The line is at 5 ml (well as near as I can tell without an analytical balance). My reagents were supplied in dropper-bottles, which seemed to give a nice consistent drop-size. Point taken about mash pH not being a particularly good indication that the alkalinity value I got was dead accurate, but the important thing is it was close enough.

[kevthebootboy]

Right,the results are in! And wrote down the following while I was doing the test,
0.54 ml first flash of pink in the tube
0.48 ml move obviouse
0.41 ml colour changed to purple
0.38 ml colour changed to pink and didn't chance again after that

so from Chris was saying 0.54 ml would be the Reading to go off? That means the alkalinty in meg/L is 2.63 acordning to the graph in the kit, looks like I've got abit of maths to do . .

[kevthebootboy]

Using the Reading of 2.63 meq/l

To treat 45 litres I need 25.4 ml of CRS does sound about right?

Edit - that's using the calculations Chris gave me..

[kevthebootboy]

Thatt's it then, sorted! I've mixed up a 10% sodium met solution,got my gypsum so I'm pretty much good to go,
I take it's a good idea to keep testing the alkalinity of my water every so offen,

Thanks again for all the help,it's very much appriciated!

[kevthebootboy]

Yep as long as that concurs with the changes in the video an in the pictures on the thread, (and assuming you have given the correct value off the table as I don't have mine to hand):

2.63 x 50 = 131.5 mg/l CaCO3

CRS required for pale ales

131.5 - 30/180 = 0.56mg/l

to treat 30l for eg: 0.56 x 30 = 16.8 mls of CRS round down to the nearest 1/2 ml (or what ever increment you can realistically measure to).

For milds subtract 100 (instead of 30), very dark milds will lots of dark malt subtract 100-150, likewise with stouts and porters, anywhere between 100-150 depending on how much dark grain you use.

Aup I was just looking at some calculations and you say for a stout I'd need to subtract up to 150 from my calculation of 131.5 mg/l caco3

How does this work?

[kevthebootboy]

Ah I see, no problem, I worked out for a mild I wouldn't need a great deal of CRS,

cheers.