Bubbleponics top up water

[Yukonbud]

Experienced grower and new to this forum but always trying to improve. Question for today: I’m growing in a bubbleponics set up and wondering about top up water between rez changes. Plants are drinking up 2 litres a day. Should it be the same solution I am using and changing out once a week or just water? (My water is ro)

[Bluey]

If you run a test on the remaining nute mix midway between res changes you'll see what the plant is taking up the most if you know your starting baseline. Prior to flower its more often than not the calmag that is depleted first.

Without testing Id just add your standard nute mix prior to correcting the pH in the res.

[Allenpro]

I have grown in hydro for for over 15 years because I love to experiment and the media for hydro growing is inert so there is no mystery in what the plants are getting . Its just whatever your giving it. Without getting into the details one of things I have had success with is I dont change the water in a grow, and before I top it off and before the flip I measure the amount of water I had to add and add nutrients equal to what that amount of water should need, I also check the PPM's frequently and I measure the sap PH so I know what is lacking or over indulging.
By the time I get to mid flower the Veg nutrients are are gone and its running mostly if not totally on flower nutes. I also learned that as the plants get closer to being ready to harvest the nutrient intake decrease and they start living on their stores. Most living things that go out naturally do the same thing
Dont take my word for it, try it yourself