Charlie asked | 20th November 2012
Question: Hi, I am interested in the autopot 4 pot kit, I was just wondering, can this system over water the plants?
I know over watering is a big killer and if its kept constantly moist it is no good either, so how exactly does the system work?
Answer: You are certainly right in asking that question and that is why it is important that the irrigation system is not attached until the plants have become established in the Autopot pot. This means that you will have to hand water until you see roots appear in the drain holes and at this point I would then open the in-line tap to initiate the automatic irrigation. To establish the plants, I would follow something that we call the 'half weight' rule and what this means is that when you pre-wet your growing media when you plant-out to saturation, then pick up the pot to get a feel for the weight and do not water any liquid into the pot again until the pot weighs half this saturated weight. This process stimulates the roots to find the wetter media toward the bottom of the pot. If you keep the media at saturation then the plants will not establish properly and you will not realise your yield potential. The irrigation operates by the opening and closing of a valve in the bottom of the Autopot tray. The valve allows nutrient/water to pass into the tray to a depth of approximately 25mm and then will not let any more liquid in until this has been used. This does keep the pots at their saturation point but once the plants have been established prior to this then it is not a problem and system works very well. Part of this is due to the height of the pot. The pots are quite deep which allows the upper parts of the pot to carry much less water so more air occuppies the root space. The media is also quite important so I would recommend a good grade inert growing media such as coconut fibre/coir or Grodan Grow Cubes. You can use a good quality compost but make sure this is a free draining compost such as VitaLink Enriched Soil.