Please explain why water needs changed every 7 days [RESOLVED]


I’m a novice, but it seems odd that the water needs to be changed every 7 days. I’m using distilled water. Perhaps you could explain the chemistry behind this requirement?

New grow - help needed

Hi @Cat,

The idea behind changing your water every week is to ensure that your plant has less of a chance of getting root rot and also ensures you are always feeding fresh nutrient solution to your plants. When growing in a DWC system, it is important to completely change out the nutrient solution.

Think of it through this analogy (@Stephen gets the credit for teaching me it in the first place :wink: ): every week I go out and buy fresh bananas, oranges, and apples for my kids. When I get home I place them all in piles on the kitchen table for them to eat; however, at this point I cannot see what’s left on the table anymore. Depending on what the kids are feeling that week they’ll eat a random combination of the fruits, or even might munch down on only one of the groups of fruits. So, the next week when I do my grocery run I end up buying the same amount of each fruit. The only difference this week is that I’ll clear the entire table before putting the new fruits on the table to make sure that there’s nothing rotting, which could potentially poison the kids. It’s the same way with the nutrients we’re giving to your plants; if we were to keep dosing the same amount of nutrients every week without cleaning the water first, we could potentially poison the plant with an excess of any of the nutrients

Hope that helped :slight_smile:


Well put my friend. Excellent analogy!!!


@Chris @Stephen

I was notified to do the first drain and fill today. My seed hasn’t sprouted but does have a small root. Should I still do the recommended water change or wait until I see the seed sprouting?


Yup, do it. Replenishes with fresh nutes and water.


Yes always do what it says!


@rouleauj even if my plant hasn’t started growing? I’d think maybe we would want to delay as the notifications have nothing to do with what is actually going on inside the grobo


Do it even if it hasn’t sprouted. The tap root showing it’s lovely head is a great sign. It needs nutrients and fresh water.


Like @rainstorm3 said. You said it had a tap root and is going. Nature will take care of the rest for now, then will come @Stephen .


What day?..I figure day 7 as you just got your drain and fill notification. A bean can take up to 10+ days to sprout before you might need to chuck her. As you have a tap root already observed, the nutes dispensed after said drain and fill will ultimately help your girl sprout quickly now. Genetics and feeding schedule will determine how she grows now. Be patient. And keep us posted.


As everyone already mentioned here @Gatorsfn28 it’s best to follow the drain/fill schedule to make sure that your plant has the potential to do its best :ok_hand:




6 posts were split to a new topic: Water Levels




I am leaving today and will be away 4 days visiting family. It has been a week since I began my grow and have not, as of yet, received a notification to drain or do a reservoir change. I have a sprouted seedling showing. Is there a way to manually drain the unit and then refill it before notification? My app does not seem to respond when I go in to the maintenance drop down box and click on drain.



Is your Grobo light in the front slowly blinking blue? (this will confirm that you are connected to your wifi)… If it is blinking fast blue, (this means it is looking for wifi, and the website will not work with the unit) Other than that you can put in a (SupportTicket) :ticket::tickets: and they can help you with this issue… :crossed_fingers::crossed_fingers:


Thanks, it says it’s connected and the light is a slow pulsing light blue. However the drain function did not activate when I clicked it under maintenance. I did submit an inquiry so hopefully the tech guys can tell me what is going on. However, I’m out of town till Friday so hopefully it won’t be a problem



It sounds like you need to put the light in front of the Grobo to green and go into (Settings/Reconnect to Wifi again) when you get back to activate the website to your Grobo… :crossed_fingers::crossed_fingers:


@Andyrmt did @SilverGrobo 's suggestion work? If not please send in a ticket to and we’ll be able to help yah out

You can do a ‘manual’ Drain and Fill by going into your side nav --> Maintenance --> Fill or Drain to do whatever action you want to do




Yes, all good thanks