Nutrient bottle #2 [RESOLVED]

Only distilled water from the beginning. It has to be an issue with the system dispensing too much nutes or the distilled water I’m buying from my local metro supermarket is crap.

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And here are all my bottles on day 12.

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Had the same exact issue, it’s due to the PH being faulty and not working the way it’s supposed to, and therefore it misreads the PH of the reservoir at a higher and constant range( mine was 7), so the system is reading your reservoir at a higher value than desired, and so it keeps dumping the PH Low bottle into the reservoir to bring the PH down, even though in reality it has been lowered, the system reads it as not being lowered and still at the same prior value, and so it just keeps dumping the Acidic bottle even further making ur system really Acidic, essentially having a really really low PH, which would definitely affect plant growth negatively. You should send in a ticket to diagnose the exact issue, and in the meantime, just take out both bottles 1 and 2 from the the unit, and do a new drain and fill with fresh distilled water to fix the state of the reservoir, and you should deff get a back up PH and EC meter to check the range of your res, and if PH needs adjustments you can do it manually by dropping in some. You can do this until the issue is fixed and it can adjust the PH itself automatically again.


Hey @Stephane

Bottle #5 looks normal it uses a bit more then 3 & 4 with distilled water. Grobo guys should be checking your pH shortly since you sent a ticket in, :+1:

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Hey @CookieGrower

I totally understand the science of pH I remember seeing this issue with you and at least one other grower. What was the final resolve? My guess is either a replacement pH sensor or calibration of the existing one?

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Thank you all for the great advice. I ordered a PH and EC testing kit off amazon. I will wait to drain and fill until @Stephen can look at the data and figure out what went wrong.

Once I get an answer I will give my beloved plant some fresh distilled water and I will test manually and adjust accordingly.

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My bottle 5 hasn’t used an inch of liquid. I’ve replaced bottle 4 and am about to replace bottle 2.

I assume everything will be different based on the water they use.

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Hi @Stephane,

Houston, we have a problem! I’ll shift over to my support voice and dig in with @GroboJason. Help is on the way!!



Here is an update for inquiring minds,

So far I have investigated the tubing system for kinks in the lines and I found the drain/fill hose was pressing against the hose going into bottle number 2. I moved the small white hose to the right a little and that did the trick for removing any possible kinks.

Said that I don’t believe that the issue is with the product not being dispensed to the DWC tank and more so what @CookieGrower was saying with reference to the PH sensor not functioning properly and telling the system that it is too alkaline and dumping the number two bottle to bring the PH down continually.

Said that the geniuses over at Grobo are working diligently to solve this issue and I will keep everyone up to date.

For now all I can do is fire on the Volcano and fill up a bag and relax :slight_smile:


Update time, @GroboJason called me this morning to do a couple of test on the system. Let me just say its pretty cool how much control you guys have over every function of the Grobo at a distance.

To start I carefully removed the cover and my beloved plant and placed it on top of a bucket and placed a towel around the holes to minimize the amount of light the root system was going to be exposed to. Then we proceeded with a partial drain to expose the hoses for the nutrient bottles and Jason activated the pump number two and determined that solution number two was definitely flowing into the tank.

So now at this point ill receive a testing kit for the PH sensor and proceed to the next step of seeing what numbers the PH sensor will give.

Little bumps along the road to success but we’ll get there.

Thanks again Grobo team for being awesome.


Here is a more recent picture of my white widow. She seems in good health.


I just got my nutrient kit in the mail today. I’m just hesitant to put the new #2 bottle in as to not waste it.

Im on day 14 so I’m due for a complete water change. Should I just proceed with the water change and just simply test the distilled water with my portable pH meter. If the pH level isn’t through the roof and doesn’t need to be lowered with acidic, omit the number 2 bottle until all the trouble shooting on my Grobo is completed?

Please let me know your thoughts.

Thanks a million.

That’s what I would do until the issue is resolved your system may just dump the contents of the bottle into the resevouir. Bottle #2 for me with distilled water has only used 1/3 of the bottle in over 100 days of growing. :man_shrugging:


She is still doing good despite everything. Cannabis is one hell of a resilient plant. :sunglasses:


Ok I did a full water change yesterday. Today I wanted to see what the PH of the water was so I took out a sample out of the tank and tested it. The reading I got was 5.8 and I’m pretty sure thats around the range it should be.

Said that my little PH meter is nowhere near as good quality as the one that comes with the unit and there could be some slight fluctuations in that number.

I’m trying my best to keep the light off the roots but it has been difficult lately due to all the trouble shooting and I noticed today a good portion was discoloured brown but did not seem to have any signs of slime like substance on the surface so I will chock it up to possibly stained by the nutrients.

Here is a pic of her today(day 16). notice the two leaves that seem pretty shrivelled up. I really hope its not a sign of something bad.

The new growth seems really good.

let me know if i’m missing anything.

Thanks :slight_smile:

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Hey @Stephane, I think you’re right on point with how the new growth looks which is very healthy. To me just looking at the picture it seems she has said, “forget these two leaves.” I would continue to do what you’re doing and monitor new growth. Said leaves turn yellow or enough time goes by, you’ll cut them off anyways. :+1:


Update time!(Day 19)

Today I tested the pH Levels in my water and it was sitting at 5.4. Did a fill to top up my reservoirs and added 1ml of Basic to raise that number a little bit. Will monitor and adjust as needed.

Wish me luck :slight_smile: :green_thumb:

Edit: RH is low and will be adding humidifier.




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Yesterday @GroboJason and I did the full calibration on the pH Probe.
Started out by gently lifting the cover and removing the pH probe. I noticed quite a bit of red/brown coloured algae growing on the tip of the probe. I cleaned it with the pH probe cleaning solution and the tooth brush that came with the kit.

Completed the calibration process with the included solutions in the kit and help from Jason. I was lucky because I was on day 21 so right after the calibration I did a complete drain/fill and I replaced the #2 bottle in the Grobo.

So far so good the #2 bottle hasn’t been touched which wasn’t the case beforehand. I will continue to monitor but I think that did the trick.