When to change out water?

When are you supposed to change out the water will :loudspeaker: you or just every 7 day’s


It will send you a reminder like 15-20 minutes after Day 8 starts, so you get a Full 7 days out of the water and then switch.

If you ever do a water change not on these days for one reason or another, the notifications will no longer be accurate though.

You can technically change the water as often as you’d like!

Don’t forget it’s a good idea to FILL and top off the reservoir during the 7 day period, too. Usually, once a week during Early veg, twice in Late veg, then every two days in flower, and then towards the end, every day… Something along those lines… You’ll have to feel it out and judge how much water it uses to make the call

General way to think about it is the bigger your plant, the thirstier it will be.


Appreciate the info. So far so good sprouted on the 4th day. Let’s see with help and learning how this goes


Day 8 here. Just finished my first drain and fill.

Some “notes”:

**Have a container large enough to hold the 2-3 gal. A 5 gal bucket would be prudent.

**Although you can “pause” the drain function, say if your container you’re draining into is getting full, the app will suddenly call you drain complete. You’ll then have to restart the drain function through the maintenance section of the app. (See above note to avoid this).


I’m in a habit of not letting pumps of any type cavitate. When my hose started sucking wind, I stopped the drain function. This does not allow the programming to finalize giving you a “Grobo is busy draining” message when you try to fill. Coincidentally, when I tried to restart the drain process, I also got the “Drain Complete” message on the app. The app may have thought we were done, but the unit itself was disagreeing.

So, moral of the story…let that sucker drain until it’s sucking air and you get the green lights from the unit. (Mine sucked wind for nearly 10 sec before it decided it was good)

Hope this helps.

I’m sure there are others in here with similar stories or tips, but I didn’t go “a-searching”