Drain/Fill with water chiller

Those who have been running water chillers in conjunction with your Grobo:

What process do you use for draining/filling your reservoir? I am positive that the chiller adds to the process, just want to be sure that I am not missing anything when it comes time to drain/fill. Thanks in advance!

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(The Best Way To Controle Your [WaterTemperatures] is to Controle the room that you have your Grobo in): (For us we will probably go with the [Extra liquids]):

(Although [HydroGuard], [Revive], [Recharge] will help your roots explode): (Apply all three to save plant and Root System):




Thanks Silver,

I’ve read all of these, no one touches on exactly how they handle drain/fill. Looking for a step by step guide if possible! Is it as simple as just turning off the cooler so that it doesn’t freeze up, turning off the pump, and running the drain function, then priming the pump during fill, and once reservoir is full and sufficient water is flowing you turn the chiller back on and your done?

The part that concerns me is the “old” water that gets left behind in the chiller, is it ok for that much of it to stay in the system? Or is there a step you must take to get it out during the drain? Also, are there any other steps I’m missing?

Thanks again, I’ve been checking out your grows, inspiring!

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I have a shut off valve on both hoses at the entry/exit point out of the Grobo.
I just shut both valves off, do the drain/fill, and open the valves back up.



Any idea how much water stays in the chiller/input/output tubes? I worry that the additional water added to the grobo after it’s filled to the precise level The recipe calls for could have negative effects.

No clue and it’s not something I have been worried about (maybe my ignorance).
The water in the chiller/tubes is a separate reservoir.
It’s level is always consistent.
When you stop the flow of water to/from the chiller, the chiller is at 100% as the same amount of water that flows out is the same amount of water that always flows in.

Grobo is also it’s own reservoir and it knows based upon sensors how much water needs to be in that reservoir. When you execute the fill command, it will only fill as much as this reservoir needs. When the fill is complete, this reservoir is now at 100%.

When you turn your valves back on, water will start flowing into the Grobo reservoir, but the same amount of water will also be flowing back out. So the Grobo reservoir will never increase or decrease levels as the chiller reservoir was at 100%.

I probably didn’t explain it the best, but this is how I see it. I know Grobo Support says they do not support the machine with attached chillers, but I don’t understand how having a chiller impacts a recipe. Thoughts?

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Well I feel like an idiot haha you are exactly right! Doesn’t matter whether you leave water in or not as the amount circulating is a constant. Your method is easier, once this grow is completed I will add open close valves to input and out put tubes.


Have you flushed a plant while using the water chiller? If so, how did you clear the water from the chiller/tubes?

Good question!!

I have another valve :slight_smile:

My pump OUT line has a Y, one going to a drain, one going into the Grobo.
When I flush, I turn the 2 valves on the IN/OUT lines at the Grobo to OFF.
I then proceed with the flush.
I also then drain the water chiller by opening my drain valve at the Y.

Well good news for me, I inadvertently built in a drain line by adding the same set up for priming the pump haha. Will need add the valves coming in and out of Grobo however.

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You can opt to just unplug your pump instead of adding valves.
Will achieve the same result.
I just did valves because I have so many things plugged in and my power strips are hard to reach. Plus I kept unplugging the wrong thing!

Good call! Another question, do you run the chiller during germination or is that counter intuitive as you want warmer temps during this portion of the grow?

Correct- no need to run it if the roots aren’t in the water. I turn it on once the roots start coming down.


Thanks again!

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