simonc by tank I meant reservoir, not boiler.
Did I say boiler? 🤔
What I’m saying is, unless you know that you have exactly 2 litres of “pure” water in the tank, then yes, it’s absolutely fine to just dose the minerals into it directly, providing you have accurate instruments which can measure the desired amount of solubles. I would then give it a good stir to make sure everything is dissolved properly.
If you are just topping up the tank to a 2L mark with pure water and then adding the soluble to water which is already treated, you’ll be increasing the overall concentration.
If it was me, I would do it all into a 2L container, shake it well and then top up the tank with it.
The reason why we use a concentrate solution is so that it significantly helps with precision. For instance, it’s a lot simpler, accurate and easier to first make a concentrate of 100ml containing 1g of sodium bicarbonate (or 10g of sodium bicarbonate for a 1L concentrate) and then mix 10ml of such concentrate into 1L of pure water. Rather than use scales which you trust are accurate and precise and mix 0.20g (200mg) of sodium bicarbonate into 2L of water.
Hope that helps. 👍
