If you are using distilled you will need to reconstitute it. But you may not have to even use it. Google your local water report. Your local water likely contains adequate cal-mag and micro nutrients. So if you go 100% distilled you will need to add cal-mag and micro's like iron, manganese etc. Prob the best option if you have hard water is to mix it with R/O and not fully replace it (in my opinion).
I run at 68F you may need to buy a chiller to achieve this.
Great looking roots!!! Yeah some prefer sterile, I prefer to go with a bacteria but the 2 methods should not be mixed. There are reasons why some don't have success. I come from an aquatic background and have a lot of experience using beneficial bacteria to aid in growing aquatic plants. They are easily kept happy but can easily be killed off if you don't understand them. I mean personally i think the directions for hydrogaurd are made for marketing purposes and the culture of water changes in DWC would have to change in order to see more success. When you change out all the water at once you are destroying the environment and often killing off the beneficial bacteria then you need to re introduce them (aka buy more product) I think we are going to start seeing more and more use as hydro growers learn about it but I won't go on about it. 65-68F would definitely be a big reason for your success.
Bottom line if it works don't change it
and you obviously are quite successful with what your doing.
