Cleaning your Grobo


Hi Growers,

There are two types of cleaning that you can do to ensure your grow goes smoothly. The 1st is sanitation and the 2nd is sterilization.

Sanitation refers to the removal of all of the debris in your unit. It is important to keep your reservoir free of dead leaves, roots and floating things. Quickly remove any spilled nutrients, excess water, or dead plant material you find. Removing dead leaves immediately reduces the risk of having pests or diseases get a foothold in your system.

To clean your intake fans, inspect them monthly and clean with compressed air shooting from the inside out.

To clean the door window front or back, use a microfiber cloth. These are very sensitive and can scratch easily.

To clean the outside or inside metal, you can use isopropyl alcohol and a soft cloth.

To clean your wood top, non abrasive soap is best as it has previously been sealed with a varnish.

Sterilization refers to the removal of all pathogens in the system and concentrates on our deep water culture tank. Here we use a solution of 50/50 water to distilled white vinegar to eliminate any bacteria, fungus, spores or viruses that may have found their way into our system. You can perform a final tap water fill and then drain to ensure that there isn’t any residuals on the tank. To clean the tank and lid:

  1. Prepare a solution of 50% water (tap is fine) with 50% vinegar.
  2. Remove the lid from the tank and scrub the underside with the solution. Rinse well and allow to dry.
  3. Drain your unit.
  4. Fill a bucket with the solution and fill the unit. Allow the unit to soak for 30 minutes.
  5. Drain your unit.
  6. Using an abrasive scrub brush and the remaining prepared solution in the bottom of the tank, scrub the sides and bottom of your tank.
  7. Fill your unit with clean water, then drain again. Wipe out the excess water in the bottom with a sponge or paper towels and do a final wipe down of all surfaces. Be careful cleaning around your water level sensors!
  8. At this point you can select a new recipe and start a new grow.

Bonus cleaning If you notice your airstone is slowing down the flow of bubbles into your tank, you can clean it too. After step 7 above, prepare a 35% hydrogen peroxide solution (mixed 1/1 with water) and pour enough into your tank to cover your air stone. Let the system sit for an hour, then fill and drain your unit. One final wipe down and you are ready to fill your unit and begin growing again!

Community Grow Photos
Community Grow Photos
See-thru glass door
Gunky Lid

@Stephen I assume this would be best practice after each grow?


Hi @rainstorm3,

Absolutely right on. I would even consider sterilizing your dwc tank after a failed germination or early seedling death. The Grobo provides an ideal growing chamber, but some things can sneak in over time.

Think prevention.



Should the sensors be removed for the cleaning process, or are they ok with or benefiting from the water/vinegar solution?


The pH of vinegar itself should be around 2-3. Mixing 50/50 with water would obviously raise that number a little. I really don’t think it would have any adverse affects on your probes.

In fact if any bacteria has found a home on your probes it would take care of them.

However I’m not an expert so please chime in if I’m wrong.


On our cleaning day, we hung up the sensors both up in the Flush water that came from the Grobo… Like this…



Do those probes need to be kept wet? I emptied and dried out my Grobo today, so they have been dry a couple of hours now.


The pH probe does indeed need to be kept wet. The EC one should be fine it came in a dry tube to protect it.

Get your pH probe wet ASAP.



Thanks so much for the heads up! I don’t know which is which, so I’ve got both probes soaking in distilled water now.