Should I add chemicals to top-up water?

[Ckilner]

I brew with a Braumeister 50 and use reverse osmosis water. My recipes are generated by Beersmith which also makes the water adjustment calculations for me. I like to brew large batches to go into my 1/2bbl fermenter which don't fit in the Braumeister. What I tend to do is brew, sparge and then top up with water into the fermenter to make up the desired volume. What I can never decide on though is whether I should add chemicals to the top-up water.
I add chemicals and acid to the mash. I add chemicals to the sparge but should I add chemicals to the top-up water?

Thoughts welcome please.

 

[Coalminer]

Not necessary I believe, but I don't use reverse osmosis water

 

[MHB]

Maybe!

Really that’s often the answer to brewing questions. The amount of some salts plays a big role in the flavour of the finished beer. Good example being the amount of Sulphate in a Newcastle brown ale.
All salt additional are a range, if the amount you use in the brew is high enough to give you the desired amount after dilution, then probably not necessary. Obviously if after dilution you don’t have your target concentration then it would be a yes.
The pH likewise, if your beer isnt finishing at target then tweeking it can make a big difference.
Probably has a lot to do with just how much you are diluting your wort.
Mark

 

[Hip Hops Don't Stop]

I've just started all grain brewing, the chemicals part is a bit of a mystery to me.

Do I need to check my local water supplier for the composition?

Edit: Found it

Measurement		Result	Compliant
Aluminium		<0.01 mg/L
Dichloroacetic acid		0.006 mg/L
Ecoli		100.0%*
Mono chloroacetic acid		<0.005 mg/L
Trichloroacetic acid		0.013 mg/L
Trihalomethanes		0.035 mg/L
Turbidity		0.3 NTU

 

[Hip Hops Don't Stop]

Measurement		Result	Compliant
Chlorine		1.00 mg/L
Coliforms		N/A
Colour		<2 HU
Copper		0.001 mg/L
Electrical Conductivity		74 µS/cm
Fluoride		0.76 mg/L
Hardness		25 mg/L CaCo3
Iron		0.02 mg/L
pH		7.5 pH