Pregrow questions

Well first of all, after some light reading I checked to make sure my sensor probes fit in their holes and they do. :clap::clap:

Upon doing this, I was aggravated not for the first time, that the light goes out as soon as I open the door and when I turn it on again it lasts exactly 28 seconds. Is this normal is there’s no grow going on?

I notice there’sa lot of dust and shipping debris in my water reservoir. Is there a good way to clean this out before my first grow to help ensure success? I don’t want any of that debris messing with my plant!
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Thank you growers!!


Where isyour air stone?
Damped towel with water for the dust.
Yes the lighting is normal. Its why there are so many different types of photos on here.


The light timer has been on our list of changes we’ve requested from the Grobo staff. I believe @Stephen mentioned that it is on their to-do list, but other things are higher on their priority list.

What I did before I used mine for the first time was to fill it (select a recipe or it won’t fill all the way to the high float valve) and drain it a couple times. If you have a floral sprayer you can use that to help flush the crud to the bottom of the reservoir. There will always be some water left over in the reservoir, this is so your probes never dry out, so you’ll have to either use some towels or shop-vac to get the rest of the water out.

If you do the drain and fill method to clean it out make sure you disconnect your nutrient bottles to make sure you don’t waste it.

I just noticed @Todd.grobo asking about your air stone, is it under the bracket that holds the probes and nute tubes?


It looks like it was there at one point, wonder if it dislodged during shipping?


Are either of those parts it? They don’t move if so. Where is it supposed to be?

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Is there tape or glue under it? Should be in the middle of the reservoir
Imho its the only mandatory spare part you must have as youll lose your plant if it dies.

Yes there’s tape on the bottom of the pumice stone. I moved it to the middle. Does the tape stay? Does the stone stay on the bottom or float?

After you first asked me about the stone I went to the grobo site to see about ordering one and ??? There isn’t one that I can find?? On a happier note, while there I spun a free grow set!! :grin: I wonder if it’s still there :thinking:

So. Amazon? Or? What’s next teach​:question::grin:

I was thinking “it should be in the middle of the reservoir” too, but wondered if it might just be the “new placement”?

I’ve experimented with various placements of air stones (3 of them) and I found the roots tend to follow the flow of the current and that can somewhat be controlled based on where the stones are placed.

If it’s not a mistake, I’d bet that was done to keep the roots away from the drain hoses.

I’ve managed to get my roots tangled around the float sensors when my stones were placed in a “bad” way.


Typically its glued in place. Hardest thing i had to remove. I like the middle as i know it dispersed the nutes more evenly then crammed in a corner. When had 2 the roots were everywhere.
It will likely float which is an issue potentially. Confirm with support.

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My Grobo has been here for 15 days; I don’t recall seeing one in the center of the Grobo… I’m pretty sure it’s glued for a reason, and there wasn’t a single direction at all in the set up that referred to it. So, I’m gonna assume it’s supposed to be right where it is as per manufacturing.

The small chance that it was supposed to moved…well I’ve been reading these forums for over a month now and I haven’t seen a single thing talking about moving your air stone in the Grobo…Also I would be upset with the lack of instruction in the set up… so again I’m assuming it’s all good o_O

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Alrighty… I haven’t submitted a ticket yet about my air stone. I really like @pyromancy ‘s theory. I moved it back and cleaned my baby up and it bubbles. At this point there’s less sticky but I let it run for about 1/2 hour bubbling and didn’t encounter issues in that time.

More clean and shiny pics. Seeds arrive tomorrow!! I’m ready! (I think :thinking:)

More general questions have popped into my head. Anyone know why my nutrient tubes are all yellow? I see other people’s and theirs aren’t yellow, some are, some aren’t, but out of the box? And the tubes seem like they barely reach into the water tank. What tells the grobo to feed your plant? The water or the recipe?

And what’s all this sticky gunk under my reservoir lid? I got most of it cleaned off, this is what’s left.

Oh yeah, another one. Of many many to come I’m sure. I keep seeing people asking about the ph levels of the water. So we need a kit? What’s the probe for then? Doesn’t the ph probe tell us anything??

Thanks growers!! :grin:

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Btw, I did end up asking @Dani about where to place the air stone and the answer was in the middle right under the plant.

I am totally worried about stick now. Any old double sided tape work or do I need something special that doesn’t have xyz chemicals in it?